day02

.gitignore

@@ -0,0 +1,3 @@
+2024
+2023/*
+

2024/gareth/day20/day20.go

@@ -0,0 +1,191 @@
+package day20
+
+import (
+	"container/heap"
+	"fmt"
+	"math"
+	"strings"
+)
+
+var directions = [][]int{
+	{0, 1},  // Right
+	{1, 0},  // Down
+	{0, -1}, // Left
+	{-1, 0}, // Up
+}
+
+type State struct {
+	row, col, dir, score int
+	path                 []string
+	//Would rather use tuple as key but cant get to work
+	costMap map[[2]int]int
+}
+
+type PriorityQueue []State
+
+func Part1(input string) int {
+	maze := parseInput(input)
+	_, path, costMap := solveMaze(maze)
+	cheats := findCheats(path, costMap)
+	return cheats
+}
+
+func Part2(input string) int {
+	maze := parseInput(input)
+	_, path, costMap := solveMaze(maze)
+	cheats := findCheatsPart2(path, costMap)
+	return cheats
+}
+
+func parseInput(input string) []string {
+	parts := strings.Split(input, "\n")
+	maze := []string{}
+	maze = append(maze, parts...)
+
+	return maze
+}
+
+func (pq PriorityQueue) Len() int { return len(pq) }
+func (pq PriorityQueue) Less(i, j int) bool {
+	return pq[i].score < pq[j].score
+}
+func (pq PriorityQueue) Swap(i, j int) { pq[i], pq[j] = pq[j], pq[i] }
+
+func (pq *PriorityQueue) Push(x interface{}) {
+	*pq = append(*pq, x.(State))
+}
+
+func (pq *PriorityQueue) Pop() interface{} {
+	old := *pq
+	n := len(old)
+	item := old[n-1]
+	*pq = old[0 : n-1]
+	return item
+}
+
+func solveMaze(maze []string) (int, []string, map[[2]int]int) {
+	rows := len(maze)
+	cols := len(maze[0])
+
+	// Locate start and end points
+	var startRow, startCol, endRow, endCol int
+	for i := 0; i < rows; i++ {
+		for j := 0; j < cols; j++ {
+			if maze[i][j] == 'S' {
+				startRow, startCol = i, j
+			} else if maze[i][j] == 'E' {
+				endRow, endCol = i, j
+			}
+		}
+	}
+
+	// Priority queue and visited set
+	pq := &PriorityQueue{}
+	heap.Init(pq)
+	startPath := []string{fmt.Sprintf("(%d,%d)", startRow, startCol)}
+	startCostMap := map[[2]int]int{
+		{startRow, startCol}: 0,
+	}
+	heap.Push(pq, State{startRow, startCol, 0, 0, startPath, startCostMap})
+	visited := make(map[[3]int]bool)
+
+	for pq.Len() > 0 {
+		cur := heap.Pop(pq).(State)
+
+		// If reached the end point, return the score and path
+		if cur.row == endRow && cur.col == endCol {
+			return cur.score, cur.path, cur.costMap
+		}
+
+		// Mark as visited
+		key := [3]int{cur.row, cur.col, cur.dir}
+		if visited[key] {
+			continue
+		}
+		visited[key] = true
+
+		// Explore moves
+		for i := 0; i < 4; i++ {
+			// Compute new direction
+			newDir := (cur.dir + i) % 4
+
+			// Compute new position
+			newRow := cur.row + directions[newDir][0]
+			newCol := cur.col + directions[newDir][1]
+
+			// Check bounds and wall
+			if newRow >= 0 && newRow < rows && newCol >= 0 && newCol < cols && maze[newRow][newCol] != '#' {
+				newCost := cur.score + 1
+				if oldCost, exists := cur.costMap[[2]int{newRow, newCol}]; !exists || newCost < oldCost {
+					// Update cost map
+					newCostMap := make(map[[2]int]int)
+					for k, v := range cur.costMap {
+						newCostMap[k] = v
+					}
+					newCostMap[[2]int{newRow, newCol}] = newCost
+
+					// Update path
+					newPath := append([]string{}, cur.path...)
+					newPath = append(newPath, fmt.Sprintf("(%d,%d)", newRow, newCol))
+
+					heap.Push(pq, State{
+						newRow,
+						newCol,
+						newDir,
+						newCost,
+						newPath,
+						newCostMap,
+					})
+				}
+			}
+		}
+	}
+
+	return -1, nil, nil // No path found
+}
+
+func findCheats(path []string, costLookup map[[2]int]int) int {
+
+	totalCheats := 0
+	for index, position := range path {
+
+		var row, col int
+		//Should be a better way to do this
+		fmt.Sscanf(position, "(%d,%d)", &row, &col)
+
+		for _, dir := range directions {
+			newRow := row + (dir[0] * 2)
+			newCol := col + (dir[1] * 2)
+
+			if cost, exists := costLookup[[2]int{newRow, newCol}]; exists {
+				if cost > index && (cost-index-2) >= 100 {
+					totalCheats++
+				}
+			}
+		}
+	}
+	return totalCheats
+}
+
+func findCheatsPart2(path []string, costLookup map[[2]int]int) int {
+	totalCheats := 0
+
+	for index, position := range path {
+		var row, col int
+		//Should be a better way to do this
+		fmt.Sscanf(position, "(%d,%d)", &row, &col)
+
+		for x1 := row - 20; x1 <= row+20; x1++ {
+			for y1 := col - 20 + int(math.Abs(float64(row-x1))); y1 <= col+20-int(math.Abs(float64(row-x1))); y1++ {
+				if cost, exists := costLookup[[2]int{x1, y1}]; exists && cost != -1 {
+					diff := cost - index - int(math.Abs(float64(row-x1))) - int(math.Abs(float64(col-y1)))
+					if cost > index && diff >= 100 {
+						totalCheats++
+					}
+				}
+			}
+		}
+	}
+
+	return totalCheats
+}

2024/gareth/day20/day20_test.go

@@ -0,0 +1,45 @@
+package day20
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`###############
+	#...#...#.....#
+	#.#.#.#.#.###.#
+	#S#...#.#.#...#
+	#######.#.#.###
+	#######.#.#...#
+	#######.#.###.#
+	###..E#...#...#
+	###.#######.###
+	#...###...#...#
+	#.#####.#.###.#
+	#.#...#.#.#...#
+	#.#.#.#.#.#.###
+	#...#...#...###
+	###############`)
+	assert.Equal(t, 44, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`###############
+	#...#...#.....#
+	#.#.#.#.#.###.#
+	#S#...#.#.#...#
+	#######.#.#.###
+	#######.#.#...#
+	#######.#.###.#
+	###..E#...#...#
+	###.#######.###
+	#...###...#...#
+	#.#####.#.###.#
+	#.#...#.#.#...#
+	#.#.#.#.#.#.###
+	#...#...#...###
+	###############`)
+	assert.Equal(t, 285, r)
+}

2024/gareth/day20/input.txt

@@ -0,0 +1,141 @@
+#############################################################################################################################################
+#...###...#.......###...........###...#...#####...#...#...###...#...#.........###...#.......#...#.....#.........#...........#...............#
+#.#.###.#.#.#####.###.#########.###.#.#.#.#####.#.#.#.#.#.###.#.#.#.#.#######.###.#.#.#####.#.#.#.###.#.#######.#.#########.#.#############.#
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+#...#.#.......#.#.....###.....#...#.............#.....#.#.............#...#...#...#.#...#...#.#.#...#...#...#.....#.#...#...#.#.#...#...#...#
+###.#.#######.#.###################.#################.#.#############.#.#.#########.#.###.#.#.#.#.#.###.#.#.#.#####.###.###.#.#.#.#.#####.###
+###.#.#...#...#...###...#...#.......#.......#...#...#.#...#...###...#...#.#.........#.#...#...#...#...#...#.#.......#...#...#...#.#.#...#...#
+###.#.#.#.#.#####.###.#.#.#.#.#######.#####.#.#.#.#.#.###.#.#.###.#.#####.#.#########.#.#############.#####.#########.###.#######.#.#.#.###.#
+#...#...#...#...#.....#...#.#.........#.....#.#.#.#.#...#.#.#.#...#...###.#.#.....###.#.###...###...#.....#.#...#.....#...#...#...#...#...#.#
+#.###########.#.###########.###########.#####.#.#.#.###.#.#.#.#.#####.###.#.#.###.###.#.###.#.###.#.#####.#.#.#.#.#####.###.#.#.#########.#.#
+#.#.......#...#...#...#...#.#...#.......#.....#.#.#.#...#.#.#.#.....#...#.#.#.#...#...#...#.#.#...#.....#.#...#...#...#.....#...#...#...#...#
+#.#.#####.#.#####.#.#.#.#.#.#.#.#.#######.#####.#.#.#.###.#.#.#####.###.#.#.#.#.###.#####.#.#.#.#######.#.#########.#.###########.#.#.#.#####
+#.#.#.....#...#...#.#...#.#.#.#.#...#...#.....#.#.#.#.#...#.#.#...#...#.#.#.#.#.###...#...#.#.#.......#.#...###.....#.............#...#.....#
+#.#.#.#######.#.###.#####.#.#.#.###.#.#.#####.#.#.#.#.#.###.#.#.#.###.#.#.#.#.#.#####.#.###.#.#######.#.###.###.###########################.#
+#...#.#...#...#.....###...#...#.....#.#.#...#.#.#.#.#.#...#.#.#.#...#.#.#.#.#.#...#...#.#...#.#...#...#...#.....#...#...#...#...#...#.......#
+#####.#.#.#.###########.#############.#.#.#.#.#.#.#.#.###.#.#.#.###.#.#.#.#.#.###.#.###.#.###.#.#.#.#####.#######.#.#.#.#.#.#.#.#.#.#.#######
+#.....#.#.#.#.....#...#.....#.........#.#.#.#.#.#.#.#...#...#.#.#...#.#.#.#.#...#...###.#.###...#.#...#...#.......#...#.#.#...#...#.#...#...#
+#.#####.#.#.#.###.#.#.#####.#.#########.#.#.#.#.#.#.###.#####.#.#.###.#.#.#.###.#######.#.#######.###.#.###.###########.#.#########.###.#.#.#
+#.#.....#...#...#...#.......#.###.......#.#...#.#.#...#.###...#.#.....#...#.#...#.......#.......#...#.#.#...###.......#.#.....#...#...#...#.#
+#.#.###########.#############.###.#######.#####.#.###.#.###.###.###########.#.###.#############.###.#.#.#.#####.#####.#.#####.#.#.###.#####.#
+#.#.#...........#...#...#...#...#...#...#...#...#.#...#...#...#.....#.......#.###.....#.....#...###.#.#.#.......#.....#.......#.#.###.......#
+#.#.#.###########.#.#.#.#.#.###.###.#.#.###.#.###.#.#####.###.#####.#.#######.#######.#.###.#.#####.#.#.#########.#############.#.###########
+#...#.............#...#.#.#...#...#...#.#...#.#...#.#...#.#...#.....#...#...#.#.....#.#.#...#.....#...#.#.......#.....###...###.#...........#
+#######################.#.###.###.#####.#.###.#.###.#.#.#.#.###.#######.#.#.#.#.###.#.#.#.#######.#####.#.#####.#####.###.#.###.###########.#
+#...............#.....#...#...#...###...#...#.#...#.#.#.#.#.#...#...###...#.#.#...#...#.#.....#...###...#...###.....#.....#.....#...#.......#
+#.#############.#.###.#####.###.#####.#####.#.###.#.#.#.#.#.#.###.#.#######.#.###.#####.#####.#.#####.#####.#######.#############.#.#.#######
+#.............#.#...#.....#...#.#.....#...#.#.#...#.#.#.#.#.#.....#.......#.#...#...#...#.....#.....#.#...#.....#...#...#.....#...#.#.......#
+#############.#.###.#####.###.#.#.#####.#.#.#.#.###.#.#.#.#.#############.#.###.###.#.###.#########.#.#.#.#####.#.###.#.#.###.#.###.#######.#
+#...#...###...#.....#...#.....#.#.....#.#...#.#.###.#.#.#.#...#...#.....#.#.#...###.#.###...#...#...#...#.#.....#.#...#.#...#.#...#.........#
+#.#.#.#.###.#########.#.#######.#####.#.#####.#.###.#.#.#.###.#.#.#.###.#.#.#.#####.#.#####.#.#.#.#######.#.#####.#.###.###.#.###.###########
+#.#...#...#...........#.....#...#.....#.#.....#...#...#.#.###.#.#.#.#...#.#.#.#.....#.#.....#.#.#.#.......#.....#.#.#...#...#.....#...#...###
+#.#######.#################.#.###.#####.#.#######.#####.#.###.#.#.#.#.###.#.#.#.#####.#.#####.#.#.#.###########.#.#.#.###.#########.#.#.#.###
+#.......#.#.................#.#...#...#.#...#...#.....#.#.#...#.#.#.#.#...#.#.#...#...#.#...#.#.#.#.......#.....#...#...#...........#...#...#
+#######.#.#.#################.#.###.#.#.###.#.#.#####.#.#.#.###.#.#.#.#.###.#.###.#.###.#.#.#.#.#.#######.#.###########.###################.#
+#.......#.#...#.....#...#...#.#.#...#...###.#.#...#...#...#.#...#.#.#.#.#...#.#...#.###...#.#.#.#.#.......#.......#...#.#.....#...#...#...#.#
+#.#######.###.#.###.#.#.#.#.#.#.#.#########.#.###.#.#######.#.###.#.#.#.#.###.#.###.#######.#.#.#.#.#############.#.#.#.#.###.#.#.#.#.#.#.#.#
+#...#...#...#...#...#.#.#.#...#.#.#...#...#.#.###.#.###.....#...#...#.#.#.....#...#.......#.#.#.#.#.#...#...#...#.#.#.#...###.#.#.#.#...#.#.#
+###.#.#.###.#####.###.#.#.#####.#.#.#.#.#.#.#.###.#.###.#######.#####.#.#########.#######.#.#.#.#.#.#.#.#.#.#.#.#.#.#.#######.#.#.#.#####.#.#
+###...#...#.......#...#.#.#...#...#.#...#...#...#.#...#...#.....#.....#.#.........#.......#...#.#.#...#.#.#...#.#...#.......#.#.#.#...###.#.#
+#########.#########.###.#.#.#.#####.###########.#.###.###.#.#####.#####.#.#########.###########.#.#####.#.#####.###########.#.#.#.###.###.#.#
+#.........#.....#...#...#...#.....#.........#...#.#...###.#.#...#...#...#.#...#...#...#.......#...###...#.....#...#...#.....#...#...#...#.#.#
+#.#########.###.#.###.###########.#########.#.###.#.#####.#.#.#.###.#.###.#.#.#.#.###.#.#####.#######.#######.###.#.#.#.###########.###.#.#.#
+#...#...#...###...#...#...#.......#.........#.###...#.....#...#.#...#.#...#.#.#.#...#...#...#.#.......#.......###...#.#.......#.....#...#...#
+###.#.#.#.#########.###.#.#.#######.#########.#######.#########.#.###.#.###.#.#.###.#####.#.#.#.#######.#############.#######.#.#####.#######
+#...#.#.#.#.........#...#.#.###...#...#.....#.......#.....#.....#...#.#...#.#.#...#...#...#...#.......#.#...#...#...#.#.......#.......###...#
+#.###.#.#.#.#########.###.#.###.#.###.#.###.#######.#####.#.#######.#.###.#.#.###.###.#.#############.#.#.#.#.#.#.#.#.#.#################.#.#
+#...#.#.#.#.#...#...#...#.#.#...#.....#.#...#.....#.....#.#...#.....#.#...#.#...#.#...#.....#.........#...#...#...#.#.#...................#.#
+###.#.#.#.#.#.#.#.#.###.#.#.#.#########.#.###.###.#####.#.###.#.#####.#.###.###.#.#.#######.#.#####################.#.#####################.#
+###...#...#...#...#.....#...#...........#.....###.......#.....#.......#.....###...#.........#.......................#.......................#
+#############################################################################################################################################

2024/gareth/day21/day21.go

@@ -0,0 +1,125 @@
+package day21
+
+import (
+	"strconv"
+	"strings"
+)
+
+type coordinate struct {
+	row, col int
+}
+
+var numberPad = map[string]coordinate{
+	"7": {0, 0}, "8": {0, 1}, "9": {0, 2},
+	"4": {1, 0}, "5": {1, 1}, "6": {1, 2},
+	"1": {2, 0}, "2": {2, 1}, "3": {2, 2},
+	"0": {3, 1}, "A": {3, 2},
+}
+
+var robotPad = map[string]coordinate{
+	"^": {0, 1}, "A": {0, 2},
+	"<": {1, 0}, "v": {1, 1}, ">": {1, 2},
+}
+
+type cacheKey struct {
+	sequence   string
+	iterations int
+}
+
+var memo = make(map[cacheKey]int)
+
+func Part1(input string) int {
+	codes := parseInput(input)
+
+	numpadGraph := createGraph(numberPad, coordinate{3, 0})
+	dirpadGraph := createGraph(robotPad, coordinate{0, 0})
+
+	total := 0
+	for _, code := range codes {
+		codeInt, _ := strconv.Atoi(code[:len(code)-1])
+		total += codeInt * getLength(code, 3, true, numpadGraph, dirpadGraph)
+	}
+	return total
+}
+
+func Part2(input string) int {
+	codes := parseInput(input)
+
+	numpadGraph := createGraph(numberPad, coordinate{3, 0})
+	dirpadGraph := createGraph(robotPad, coordinate{0, 0})
+
+	total := 0
+	for _, code := range codes {
+		codeInt, _ := strconv.Atoi(code[:len(code)-1])
+		total += codeInt * getLength(code, 26, true, numpadGraph, dirpadGraph)
+	}
+	return total
+}
+
+func parseInput(input string) []string {
+	parts := strings.Split(input, "\n")
+	codes := []string{}
+	codes = append(codes, parts...)
+	return codes
+}
+
+func createGraph(keypad map[string]coordinate, invalidCoords coordinate) map[string]string {
+	graph := make(map[string]string)
+
+	for a, coordA := range keypad {
+		for b, coordB := range keypad {
+			x1, y1 := coordA.row, coordA.col
+			x2, y2 := coordB.row, coordB.col
+
+			path := strings.Repeat("<", max(0, y1-y2)) +
+				strings.Repeat("v", max(0, x2-x1)) +
+				strings.Repeat("^", max(0, x1-x2)) +
+				strings.Repeat(">", max(0, y2-y1))
+
+			if invalidCoords == (coordinate{x1, y2}) || invalidCoords == (coordinate{x2, y1}) {
+				path = reverseString(path)
+			}
+			graph[a+"->"+b] = path + "A"
+		}
+	}
+
+	return graph
+}
+
+func reverseString(s string) string {
+	runes := []rune(s)
+	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
+		runes[i], runes[j] = runes[j], runes[i]
+	}
+	return string(runes)
+}
+
+func getLength(sequence string, iterations int, firstIter bool, numpadGraph map[string]string, dirpadGraph map[string]string) int {
+
+	if iterations == 0 {
+		return len(sequence)
+	}
+
+	key := cacheKey{sequence: sequence, iterations: iterations}
+	if cachedResult, exists := memo[key]; exists {
+		return cachedResult
+	}
+
+	graph := numpadGraph
+	if !firstIter {
+		graph = dirpadGraph
+	}
+
+	totalLength := 0
+	prev := "A"
+	for _, char := range sequence {
+		graphKey := prev + "->" + string(char)
+		if subSequence, exists := graph[graphKey]; exists {
+			totalLength += getLength(subSequence, iterations-1, false, numpadGraph, dirpadGraph)
+		}
+		prev = string(char)
+	}
+
+	memo[key] = totalLength
+	return totalLength
+}

2024/gareth/day21/day21_test.go

@@ -0,0 +1,25 @@
+package day21
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`029A
+980A
+179A
+456A
+379A`)
+	assert.Equal(t, 126384, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`029A
+980A
+179A
+456A
+379A`)
+	assert.Equal(t, 126384, r)
+}

2024/gareth/day21/input.txt

@@ -0,0 +1,5 @@
+985A
+540A
+463A
+671A
+382A

2024/gareth/day22/day22.go

@@ -0,0 +1,112 @@
+package day22
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+type Queue struct {
+	data []int
+	size int
+}
+
+func NewQueue(size int) *Queue {
+	return &Queue{
+		data: make([]int, 0, size),
+		size: size,
+	}
+}
+
+func (queue *Queue) Push(value int) {
+	if len(queue.data) == queue.size {
+		queue.data = queue.data[1:]
+	}
+	queue.data = append(queue.data, value)
+}
+
+func (queue *Queue) Get() []int {
+	return queue.data
+}
+
+func (queue *Queue) String() string {
+	strs := make([]string, len(queue.data))
+	for i, val := range queue.data {
+		strs[i] = fmt.Sprintf("%d", val)
+	}
+	return strings.Join(strs, ", ")
+}
+
+func Part1(input string) int {
+	secretNumbers := parseInput(input)
+
+	total := 0
+	for _, number := range secretNumbers {
+		for i := 0; i < 2000; i++ {
+			number = getNextNumber(number)
+		}
+		total += number
+	}
+	return total
+}
+
+func Part2(input string) int {
+	secretNumbers := parseInput(input)
+	memo := make(map[string]int)
+
+	for _, number := range secretNumbers {
+		seen := make(map[string]bool)
+		queue := NewQueue(4)
+		prevNumber := secretNumbers[0] % 10
+
+		for i := 0; i < 2000; i++ {
+			singleNumber := number % 10
+			cost := singleNumber - prevNumber
+			queue.Push(cost)
+			if i > 3 {
+				if _, ok := seen[queue.String()]; !ok {
+					memo[queue.String()] += singleNumber
+					seen[queue.String()] = true
+				}
+			}
+			prevNumber = singleNumber
+			number = getNextNumber(number)
+		}
+	}
+	return maxMapValue(memo)
+}
+
+func parseInput(input string) []int {
+	parts := strings.Split(input, "\n")
+	secretNumbers := []int{}
+	for _, part := range parts {
+		num, _ := strconv.Atoi(part)
+		secretNumbers = append(secretNumbers, num)
+	}
+
+	return secretNumbers
+}
+
+func getNextNumber(number int) int {
+	step1 := (number * 64) ^ number
+	step1 = step1 % 16777216
+
+	step2 := (step1 / 32) ^ step1
+	step2 = step2 % 16777216
+
+	step3 := (step2 * 2048) ^ step2
+	step3 = step3 % 16777216
+
+	return step3
+}
+
+func maxMapValue(memo map[string]int) int {
+	maxValue := 0
+
+	for _, value := range memo {
+		if value > maxValue {
+			maxValue = value
+		}
+	}
+	return maxValue
+}

2024/gareth/day22/day22_test.go

@@ -0,0 +1,23 @@
+package day22
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`1
+10
+100
+2024`)
+	assert.Equal(t, 37327623, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`1
+2
+3
+2024`)
+	assert.Equal(t, 23, r)
+}

2024/gareth/main.go

@@ -1,7 +1,7 @@
 package main
 
 import (
-	"aoc2024/day09"
+	"aoc2024/day22"
 	"fmt"
 	"os"
 	"time"
@@ -9,11 +9,9 @@ import (
 
 func main() {
 	start := time.Now()
-	data, _ := os.ReadFile("day09/input.txt")
+	data, _ := os.ReadFile("day22/input.txt")
-	fmt.Printf("part 1: %d\n", day09.Part1(string(data)))
+	fmt.Printf("part 1: %d\n", day22.Part1(string(data)))
-	fmt.Printf("part 2: %d\n", day09.Part2(string(data)))
+	fmt.Printf("part 2: %d\n", day22.Part2(string(data)))
 	elapsed := time.Since(start)
 	fmt.Printf("Execution time: %s\n", elapsed)
 }
-
-// 6320029754031

2024/go/day20/day20.go

@@ -52,14 +52,54 @@ func Part1(input string) int {
 	return dist
 }
 func Part2(input string) int {
+	const saves int = 100
+	count := 0
 	maze := Maze{}.Parse(input)
-	fmt.Println(maze)
+	//	fmt.Println(maze)
 	data := inputGraph(*maze)
 	graph := dijkstra.CreateGraph(data)
-	_, count := dijkstra.GetShortestPath(data.From, data.To, graph)
+	path, dist := dijkstra.GetShortestPath(data.From, data.To, graph)
+	cost := make(map[Vec]int)
+	cheats := []Cheat{}
+
+	for i, p := range path {
+		cost[Vec{p.X, p.Y}] = i
+	}
+	cheat_data := cheatGraph(*maze)
+
+	for _, s := range path[:len(path)-saves] {
+		fmt.Println("Checking start:", s)
+		for _, e := range path[saves:] {
+			fmt.Println("\tChecking end", e)
+			cheat_data_1 := cheatGraphAdd(maze, cheat_data, s)
+			cheat_data_2 := cheatGraphAdd(maze, cheat_data_1, e)
+			cheat_graph := dijkstra.CreateGraph(cheat_data_2)
+			_, cheat_dist := dijkstra.GetShortestPath(dijkstra.Point{X: s.X, Y: s.Y}, dijkstra.Point{X: e.X, Y: e.Y}, cheat_graph)
+			fmt.Println("\t\tcheat distance:", cheat_dist)
+			if cheat_dist <= 20 {
+				cheat := Cheat{start: Vec{s.X, s.Y}, end: Vec{e.X, e.Y}, cost: cost[Vec{s.X, s.Y}] + cheat_dist + dist - cost[Vec{e.X, e.Y}]}
+				fmt.Println("\t\tSaving cheat:", cheat)
+				cheats = append(cheats, cheat)
+			}
+		}
+	}
+	for _, cheat := range cheats {
+		save := dist - cheat.cost
+		//		fmt.Println("[", i, "]", "save", save)
+		if save >= saves {
+			count++
+		}
+	}
 	return count
 }
 
+func abs(in int) int {
+	if in < 0 {
+		return in * -1
+	}
+	return in
+}
+
 func inputGraph(maze Maze) dijkstra.InputGraph {
 	data := dijkstra.InputGraph{}
 	data.From = dijkstra.Point{X: maze.start.x, Y: maze.start.y}
@@ -89,6 +129,58 @@ func inputGraph(maze Maze) dijkstra.InputGraph {
 	return data
 }
 
+func cheatGraph(maze Maze) dijkstra.InputGraph {
+	data := dijkstra.InputGraph{}
+	for y := 0; y < maze.height; y++ {
+		for x := 0; x < maze.width; x++ {
+			if maze.grid.Get(x, y) == CORRIDOR {
+				continue
+			}
+			for _, dir := range DIRECTIONS {
+				nx, ny := x+dir.x, y+dir.y
+				if nx < 0 || ny < 0 || nx >= maze.width || ny >= maze.height {
+					continue
+				}
+				if maze.grid.Get(nx, ny) == CORRIDOR {
+					continue
+				}
+				data.Graph = append(data.Graph, dijkstra.InputData{
+					Source:      dijkstra.Point{X: x, Y: y},
+					Destination: dijkstra.Point{X: nx, Y: ny},
+					Weight:      1,
+				})
+			}
+		}
+	}
+
+	return data
+}
+
+func cheatGraphAdd(maze *Maze, in dijkstra.InputGraph, s dijkstra.Point) dijkstra.InputGraph {
+	x := s.X
+	y := s.Y
+	out := dijkstra.InputGraph{}
+	out.From = in.From
+	out.To = in.To
+	out.Graph = append([]dijkstra.InputData{}, in.Graph...)
+
+	for _, dir := range DIRECTIONS {
+		nx, ny := x+dir.x, y+dir.y
+		if nx < 0 || ny < 0 || nx >= maze.width || ny >= maze.height {
+			continue
+		}
+		if maze.grid.Get(nx, ny) == CORRIDOR {
+			continue
+		}
+		out.Graph = append(out.Graph, dijkstra.InputData{
+			Source:      dijkstra.Point{X: x, Y: y},
+			Destination: dijkstra.Point{X: nx, Y: ny},
+			Weight:      1,
+		})
+	}
+	return out
+}
+
 func (m Maze) Parse(input string) *Maze {
 	m.grid = inputs.ToGrid2D(input, "\n", "", '?', func(c string) Cell { return Cell(c[0]) })
 	m.height, m.width = m.grid.SizeY(), m.grid.SizeX()

2024/go/day20/day20_test.go

@@ -26,6 +26,20 @@ func TestPart1(t *testing.T) {
 }
 
 func TestPart2(t *testing.T) {
-	r := Part2("")
+	r := Part2(`###############
+#...#...#.....#
+#.#.#.#.#.###.#
+#S#...#.#.#...#
+#######.#.#.###
+#######.#.#...#
+#######.#.###.#
+###..E#...#...#
+###.#######.###
+#...###...#...#
+#.#####.#.###.#
+#.#...#.#.#...#
+#.#.#.#.#.#.###
+#...#...#...###
+###############`)
 	require.Equal(t, 0, r)
 }

2024/go/day21/day21.go

@@ -0,0 +1,181 @@
+package day21
+
+import (
+	"adventofcode2024/utils"
+	"adventofcode2024/utils/dijkstra"
+	"adventofcode2024/utils/memo"
+	"fmt"
+	"math"
+	"strings"
+)
+
+type Pair struct {
+	s dijkstra.Point
+	d dijkstra.Point
+}
+
+type Path struct {
+	path     []dijkstra.Point
+	path_str string
+	cost     int
+}
+
+type State struct {
+	code         string
+	depth        int
+	isNumericPad bool
+}
+
+var numericPad = map[dijkstra.Point]string{
+	{X: 0, Y: 0}: "7", {X: 1, Y: 0}: "8", {X: 2, Y: 0}: "9",
+	{X: 0, Y: 1}: "4", {X: 1, Y: 1}: "5", {X: 2, Y: 1}: "6",
+	{X: 0, Y: 2}: "1", {X: 1, Y: 2}: "2", {X: 2, Y: 2}: "3",
+	{X: 1, Y: 3}: "0", {X: 2, Y: 3}: "A",
+}
+
+var directionPad = map[dijkstra.Point]string{
+	{X: 1, Y: 0}: "^", {X: 2, Y: 0}: "A",
+	{X: 0, Y: 1}: "<", {X: 1, Y: 1}: "v", {X: 2, Y: 1}: ">",
+}
+
+var directions = []dijkstra.Point{{X: 0, Y: 1}, {X: 0, Y: -1}, {X: 1, Y: 0}, {X: -1, Y: 0}}
+
+var lookup_np = get_paths(numericPad)
+var lookup_dp = get_paths(directionPad)
+
+var m *memo.Memo
+
+func init() {
+	m = memo.New(get_shortest_path)
+}
+
+func Part1(input string) int {
+	codes := strings.Split(input, "\n")
+	cost := 0
+	for _, code := range codes {
+		initialState := State{
+			code:         code,
+			depth:        2,
+			isNumericPad: true,
+		}
+		result := m.Get(initialState).(int)
+		cost += result * utils.MustAtoi(code[:len(code)-1])
+	}
+	return cost
+}
+
+func Part2(input string) int {
+	codes := strings.Split(input, "\n")
+	cost := 0
+	for _, code := range codes {
+		initialState := State{
+			code:         code,
+			depth:        25,
+			isNumericPad: true,
+		}
+		result := m.Get(initialState).(int)
+		cost += result * utils.MustAtoi(code[:len(code)-1])
+	}
+	return cost
+}
+
+func get_paths(in map[dijkstra.Point]string) map[Pair][]Path {
+	lookup := make(map[Pair][]Path)
+	data := dijkstra.InputGraph{}
+	for p := range in {
+		for _, dir := range directions {
+			np := dijkstra.Point{X: p.X + dir.X, Y: p.Y + dir.Y}
+			if in[np] != "" {
+				data.Graph = append(data.Graph, dijkstra.InputData{
+					Source:      p,
+					Destination: np,
+					Weight:      1,
+				})
+			}
+		}
+	}
+	graph := dijkstra.CreateGraph(data)
+	for s := range in {
+		for d := range in {
+			paths, cost := dijkstra.GetAllShortestPaths(s, d, graph)
+
+			for _, path := range paths {
+				path_str := ""
+				for x := 1; x < len(path); x++ {
+					f := path[x-1]
+					t := path[x]
+
+					switch {
+					case f.X == t.X && f.Y < t.Y:
+						// Moving verticallY down
+						path_str += "v"
+					case f.X == t.X && f.Y > t.Y:
+						// Moving verticallY up
+						path_str += "^"
+					case f.Y == t.Y && f.X < t.X:
+						// Moving horizontallY right
+						path_str += ">"
+					case f.Y == t.Y && f.X > t.X:
+						// Moving horizontally left
+						path_str += "<"
+					default:
+						// No matching case or invalid input
+						fmt.Println("Invalid direction")
+					}
+
+				}
+				lookup[Pair{s, d}] = append(lookup[Pair{s, d}], Path{path, path_str, cost})
+			}
+
+		}
+	}
+	return lookup
+}
+
+func find_point(in string, lookup map[dijkstra.Point]string) dijkstra.Point {
+	for k, v := range lookup {
+		if v == in {
+			return k
+		}
+	}
+	return dijkstra.Point{}
+}
+
+func get_shortest_path(key interface{}) interface{} {
+	state := key.(State)
+
+	if state.depth < 0 {
+		return len(state.code)
+	}
+
+	// (Optional) If you need to modify the state, work on a copy.
+	newState := state
+	newState.code = "A" + state.code
+
+	cost := 0
+	for x := 0; x<len(newState.code)-1; x++ {
+		pps := shortest_paths(string(newState.code[x]), string(newState.code[x+1]), newState.isNumericPad)
+		min := math.MaxInt // Start with a very high number not just 65535
+		for _, pp := range pps {
+			nextState := State{
+				code:         pp.path_str + "A",
+				depth:        newState.depth - 1,
+				isNumericPad: false,
+			}
+			mm := m.Get(nextState).(int)
+			if mm < min {
+				min = mm
+			}
+		}
+		cost += min
+	}
+	return cost
+}
+
+func shortest_paths(s, d string, isNumericPad bool) []Path {
+	if isNumericPad {
+		return lookup_np[Pair{s: find_point(s, numericPad), d: find_point(d, numericPad)}]
+	} else {
+		return lookup_dp[Pair{s: find_point(s, directionPad), d: find_point(d, directionPad)}]
+	}
+}

2024/go/day21/day21_test.go

@@ -0,0 +1,25 @@
+package day21
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`029A
+980A
+179A
+456A
+379A`)
+	require.Equal(t, 126384, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`029A
+980A
+179A
+456A
+379A`)
+	require.Equal(t, 126384, r)
+}

2024/go/day21/input.txt

@@ -0,0 +1,5 @@
+480A
+965A
+140A
+341A
+285A

2024/go/day21/tt

@@ -0,0 +1,9 @@
+
+v<A <A A >>^A v<<A>A<A>>^AvAA<^A>AvA<^A>vA^A
+<vA <A A >>^A vA A <^A >A      <v<A>>^AvA^A<vA>^A<v<A>^A>AAvA^A<v<A>A>^AAAvA<^A>A
+  v  < <    A  > >   ^  A      <A>AvA<^AA>A<vAAA>^A
+            <           A                            ^A>^^AvvvA
+0                              29A
+
+
+

2024/go/day22/day22.go

@@ -0,0 +1,91 @@
+package day22
+
+import (
+	"adventofcode2024/utils"
+	rb "adventofcode2024/utils/ringbuffer"
+	"strconv"
+	"strings"
+)
+
+func Part1(input string) int {
+	var secret uint
+	total := 0
+	secrets := strings.Split(input, "\n")
+	for _, secret_str := range secrets {
+		secret = uint(utils.MustAtoi(secret_str))
+		for i := 0; i < 2000; i++ {
+			secret ^= secret * 64
+			secret %= 16777216
+			secret ^= secret / 32
+			secret %= 16777216
+			secret ^= secret * 2048
+			secret %= 16777216
+		}
+		total += int(secret)
+	}
+	return total
+}
+
+func Part2(input string) int {
+	var secret uint
+	var banannas0, banannas1, banannas2, banannas3, banannas4 int
+	seq_map := make(map[string]int)
+	total := 0
+	ringBuffer := rb.NewRingBuffer[uint](5)
+
+	secrets := strings.Split(input, "\n")
+	for _, secret_str := range secrets {
+		found_map := make(map[string]bool)
+		secret = uint(utils.MustAtoi(secret_str))
+		for i := 0; i < 2000; i++ {
+			secret = get_next_secret(secret)
+			ringBuffer.Add(secret)
+			if ringBuffer.Len() < 5 { continue }
+			ring := ringBuffer.Get()
+			banannas0 = get_bannnas(ring[0])
+			banannas1 = get_bannnas(ring[1])
+			banannas2 = get_bannnas(ring[2])
+			banannas3 = get_bannnas(ring[3])
+			banannas4 = get_bannnas(ring[4])
+			map_str := diff_bannanas(banannas1, banannas0) +
+				diff_bannanas(banannas2, banannas1) +
+				diff_bannanas(banannas3, banannas2) +
+				diff_bannanas(banannas4, banannas3)
+			if _, ok := found_map[map_str]; !ok {
+				seq_map[map_str] += banannas4
+				found_map[map_str] = true
+			}
+		}
+	}
+	for _, v := range seq_map {
+		if v > total {
+			total = v
+		}
+	}
+	return total
+}
+
+func get_next_secret(in uint) uint {
+	in ^= in * 64
+	in %= 16777216
+	in ^= in / 32
+	in %= 16777216
+	in ^= in * 2048
+	in %= 16777216
+	return in
+}
+
+func get_bannnas(secret uint) int {
+	return int(secret) % 10
+}
+
+func diff_bannanas(a, b int) string {
+	ret := ""
+	diff := a - b
+	if diff >= 0 {
+		ret = "+" + strconv.Itoa(diff)
+	} else {
+		ret = strconv.Itoa(diff)
+	}
+	return ret
+}

2024/go/day22/day22_test.go

@@ -0,0 +1,20 @@
+package day22
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1("1")
+	require.Equal(t, 8685429, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`1
+2
+3
+2024`)
+	require.Equal(t, 23, r)
+}

2024/go/day23/day23.go

@@ -0,0 +1,242 @@
+package day23
+
+import (
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+type Lan struct {
+	nodes []*Node
+}
+
+type Node struct {
+	key      string
+	adjacent []*Node
+	loops    [][]*Node
+}
+
+func Part1(input string) int {
+	total := 0
+
+	lan := &Lan{}
+
+	pattern := `^([a-z]{2})-([a-z]{2})$`
+	re := regexp.MustCompile(pattern)
+	lines := strings.Split(input, "\n")
+	for _, line := range lines {
+		matches := re.FindAllStringSubmatch(line, -1)
+		for _, match := range matches {
+			lan.AddNode(match[1])
+			lan.AddNode(match[2])
+			lan.AddConnection(match[1], match[2])
+			lan.AddConnection(match[2], match[1])
+		}
+	}
+	for _, node := range lan.nodes {
+		if node.key[0] == 't' {
+			connections := node.adjacent
+			for _, connection := range connections {
+				c := lan.getNode(connection.key)
+				for _, n1 := range c.adjacent {
+					for _, n2 := range connections {
+						if n1.key == n2.key {
+							already_found := false
+							for _, loop := range node.loops {
+								if contains(loop, c.key) && contains(loop, n2.key) {
+									already_found = true
+									break
+								}
+							}
+
+							for _, loop := range c.loops {
+								if contains(loop, node.key) && contains(loop, n2.key) {
+									already_found = true
+									break
+								}
+							}
+
+							for _, loop := range n2.loops {
+								if contains(loop, c.key) && contains(loop, node.key) {
+									already_found = true
+									break
+								}
+							}
+
+							if !already_found {
+								already_found = true
+								total++
+								loop := make([]*Node, 0)
+								loop = append(loop, node)
+								loop = append(loop, c)
+								loop = append(loop, n2)
+								node.loops = append(node.loops, loop)
+								fmt.Printf("%v,%v,%v\n", node.key, c.key, n2.key)
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+	lan.Print()
+	t := 0
+	for _, node := range lan.nodes {
+		if node.key[0] == 't' {
+			t += len(node.loops)
+			fmt.Printf("Node: %v\n", node.key)
+			for _, loop := range node.loops {
+				for _, n := range loop {
+					fmt.Printf(" %v ", n.key)
+				}
+				fmt.Println()
+			}
+		}
+	}
+	fmt.Printf("Total: %d\n", t)
+	return total
+}
+
+func Part2(input string) int {
+	total := 0
+
+	lan := &Lan{}
+
+	pattern := `^([a-z]{2})-([a-z]{2})$`
+	re := regexp.MustCompile(pattern)
+	lines := strings.Split(input, "\n")
+	for _, line := range lines {
+		matches := re.FindAllStringSubmatch(line, -1)
+		for _, match := range matches {
+			lan.AddNode(match[1])
+			lan.AddNode(match[2])
+			lan.AddConnection(match[1], match[2])
+			lan.AddConnection(match[2], match[1])
+		}
+	}
+	for _, node := range lan.nodes {
+		connections := node.adjacent
+		for _, connection := range connections {
+			c := lan.getNode(connection.key)
+			for _, n1 := range c.adjacent {
+				for _, n2 := range connections {
+					if n1.key == n2.key {
+						already_found := false
+						for _, loop := range node.loops {
+							if contains(loop, c.key) && contains(loop, n2.key) {
+								already_found = true
+								break
+							}
+						}
+
+						for _, loop := range c.loops {
+							if contains(loop, node.key) && contains(loop, n2.key) {
+								already_found = true
+								break
+							}
+						}
+
+						for _, loop := range n2.loops {
+							if contains(loop, c.key) && contains(loop, node.key) {
+								already_found = true
+								break
+							}
+						}
+
+						if !already_found {
+							already_found = true
+							total++
+							loop := make([]*Node, 0)
+							loop = append(loop, node)
+							loop = append(loop, c)
+							loop = append(loop, n2)
+							node.loops = append(node.loops, loop)
+							fmt.Printf("%v,%v,%v\n", node.key, c.key, n2.key)
+						}
+					}
+				}
+			}
+		}
+	}
+	lan.Print()
+	maxLoop := 0
+	var maxNode *Node
+	for _, node := range lan.nodes {
+		if len(node.loops) > maxLoop {
+			maxLoop = len(node.loops)
+			maxNode = node
+		}
+	}
+	fmt.Printf("Max: %d\n", len(maxNode.loops))
+	nodeList := make([]*Node, 0)
+	keyList := make([]string, 0)
+	for _, loop := range maxNode.loops {
+		for _, l := range loop {
+			if !contains(nodeList, l.key) {
+				nodeList = append(nodeList, l)
+				keyList = append(keyList, l.key)
+			}
+		}
+	}
+	sort.Strings(keyList)
+	fmt.Println(strings.Join(keyList, ","))
+	return len(nodeList)
+}
+
+func (g *Lan) AddNode(key string) {
+	if !contains(g.nodes, key) {
+		g.nodes = append(g.nodes, &Node{key: key})
+	}
+}
+
+func (g *Lan) AddConnection(from, to string) {
+	fromNode := g.getNode(from)
+	toNode := g.getNode(to)
+
+	if fromNode == nil || toNode == nil {
+		err := fmt.Errorf("Error: Invalid edge (%v --> %v)", from, to)
+		fmt.Println(err.Error())
+	} else if contains(fromNode.adjacent, to) {
+		err := fmt.Errorf("Error: Existing edge (%v --> %v)", from, to)
+		fmt.Println(err.Error())
+	} else {
+		fromNode.adjacent = append(fromNode.adjacent, toNode)
+	}
+}
+
+func (g *Lan) getNode(key string) *Node {
+	for i, v := range g.nodes {
+		if v.key == key {
+			return g.nodes[i]
+		}
+	}
+	return nil
+}
+
+func (g *Lan) Print() {
+	for _, v := range g.nodes {
+		fmt.Printf("\nNode %v : ", v.key)
+		for _, v := range v.adjacent {
+			fmt.Printf(" %v ", v.key)
+		}
+		fmt.Println()
+		for _, loop := range v.loops {
+			for _, v := range loop {
+				if v != nil {
+					fmt.Printf(" %v ", v.key)
+				}
+			}
+			fmt.Println()
+		}
+	}
+}
+
+func contains(list []*Node, key string) bool {
+	for _, v := range list {
+		if key == v.key {
+			return true
+		}
+	}
+	return false
+}

2024/go/day23/day23_test.go

@@ -0,0 +1,79 @@
+package day23
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`kh-tc
+qp-kh
+de-cg
+ka-co
+yn-aq
+qp-ub
+cg-tb
+vc-aq
+tb-ka
+wh-tc
+yn-cg
+kh-ub
+ta-co
+de-co
+tc-td
+tb-wq
+wh-td
+ta-ka
+td-qp
+aq-cg
+wq-ub
+ub-vc
+de-ta
+wq-aq
+wq-vc
+wh-yn
+ka-de
+kh-ta
+co-tc
+wh-qp
+tb-vc
+td-yn`)
+	require.Equal(t, 7, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`kh-tc
+qp-kh
+de-cg
+ka-co
+yn-aq
+qp-ub
+cg-tb
+vc-aq
+tb-ka
+wh-tc
+yn-cg
+kh-ub
+ta-co
+de-co
+tc-td
+tb-wq
+wh-td
+ta-ka
+td-qp
+aq-cg
+wq-ub
+ub-vc
+de-ta
+wq-aq
+wq-vc
+wh-yn
+ka-de
+kh-ta
+co-tc
+wh-qp
+tb-vc
+td-yn`)
+	require.Equal(t, "co,de,ka,ta", r)
+}

2024/go/day24/day24.go

@@ -0,0 +1,297 @@
+package day24
+
+import (
+	"adventofcode2024/utils"
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+type Network struct {
+	gates []*Gate
+	wires []*Wire
+}
+
+type State int
+
+const (
+	NA State = iota - 1
+	ZERO
+	ONE
+)
+
+type Wire struct {
+	name  string
+	state State
+}
+
+type Operation int
+
+const (
+	AND Operation = iota
+	OR
+	XOR
+)
+
+type Gate struct {
+	in  [2]*Wire
+	out *Wire
+	op  Operation
+}
+
+func Part1(input string) int {
+
+	network := &Network{}
+	network.wires = make([]*Wire, 0)
+
+	data := strings.Split(input, "\n\n")
+
+	network.AddWires(data[0])
+	network.AddGates(data[1])
+	for {
+		if network.OutputKnown() {
+			break
+		}
+		for _, gate := range network.gates {
+			//			fmt.Printf("%d: %v\n", i, gate)
+			if gate.out.state == NA && gate.in[0].state != NA && gate.in[1].state != NA {
+				switch gate.op {
+				case AND:
+					gate.out.state = And(gate.in[0].state, gate.in[1].state)
+				case OR:
+					gate.out.state = Or(gate.in[0].state, gate.in[1].state)
+				case XOR:
+					gate.out.state = Xor(gate.in[0].state, gate.in[1].state)
+				}
+			}
+		}
+	}
+	return int(network.Output())
+}
+
+func Part2(input string) int64 {
+
+	data := strings.Split(input, "\n\n")
+
+	inputs := strings.Split(data[0], "\n")
+	num_inputs := len(inputs) / 2
+	fmt.Println(num_inputs)
+	var x_value int64
+	var y_value int64
+	var z_value int64
+	y_value = 0
+	for i := 0; i < num_inputs; i++ {
+	//	y_value = 1 << i
+		x_value = 1 << i
+		network := &Network{}
+		network.wires = make([]*Wire, 0)
+		network.AddWires2("x", num_inputs, x_value)
+		network.AddWires2("y", num_inputs, y_value)
+		network.AddGates(data[1])
+		//		for i, gate := range network.gates {
+		//			fmt.Printf("%d: %v\n", i, gate)
+		//		}
+		network.SwapOutputs("z07", "rts")
+		network.SwapOutputs("z12", "jpj")
+		network.SwapOutputs("z26", "kgj")
+		network.SwapOutputs("vvw", "chv")
+
+		//		for i, gate := range network.gates {
+		//			fmt.Printf("%d: %v\n", i, gate)
+		//		}
+		for {
+			if network.OutputKnown() {
+				break
+			}
+			for _, gate := range network.gates {
+				//			fmt.Printf("%d: %v\n", i, gate)
+				if gate.out.state == NA && gate.in[0].state != NA && gate.in[1].state != NA {
+					switch gate.op {
+					case AND:
+						gate.out.state = And(gate.in[0].state, gate.in[1].state)
+					case OR:
+						gate.out.state = Or(gate.in[0].state, gate.in[1].state)
+					case XOR:
+						gate.out.state = Xor(gate.in[0].state, gate.in[1].state)
+					}
+				}
+			}
+		}
+		z_value = network.Output()
+		if x_value +  y_value  != z_value {
+			fmt.Printf("(%d):\t x:%4d\t: y:%4d z:%4d\n", i, x_value, y_value, z_value)
+		}
+	}
+	ans := []string{"z07", "rts", "z12", "jpj", "z26", "kgj", "vvw", "chv"}
+	sort.Strings(ans)
+	fmt.Println(strings.Join(ans, ","))
+	return z_value
+}
+
+func (n *Network) AddWires(data string) {
+	for _, line := range strings.Split(data, "\n") {
+		v := strings.Split(line, ": ")
+		n.AddWire(&Wire{name: v[0], state: to_state(v[1])})
+	}
+}
+
+func (n *Network) AddWire(wire *Wire) {
+	n.wires = append(n.wires, wire)
+}
+
+func (n *Network) AddWires2(w string, count int, value int64) {
+	for x := 0; x < count; x++ {
+		name := fmt.Sprintf("%s%02d", w, x)
+		v := fmt.Sprintf("%d", (value>>x)&1)
+		n.AddWire(&Wire{name: name, state: to_state(v)})
+	}
+
+}
+
+func (n *Network) AddGates(data string) {
+	// ntg XOR fgs -> mjb
+	pattern := `^([a-z0-9]{3}) (AND|OR|XOR) ([a-z0-9]{3}) -> ([a-z[0-9]{3})$`
+
+	re := regexp.MustCompile(pattern)
+	for _, line := range strings.Split(data, "\n") {
+		matches := re.FindAllStringSubmatch(line, -1)
+		for _, match := range matches {
+			n.AddGate(match[1], match[2], match[3], match[4], &n.wires)
+		}
+	}
+}
+
+func (n *Network) SwapOutputs(a, b string) {
+	_, wire1 := to_wire(a, n.wires)
+	_, wire2 := to_wire(b, n.wires)
+	for _, gate := range n.gates {
+		if gate.out.name == a {
+			gate.out = wire2
+		} else if gate.out.name == b {
+			gate.out = wire1
+		}
+	}
+}
+
+func (n *Network) AddGate(in0, op, in1, out string, wires *[]*Wire) {
+	var in [2]*Wire
+	var outw *Wire
+	*wires, in[0] = to_wire(in0, *wires)
+	*wires, in[1] = to_wire(in1, *wires)
+	*wires, outw = to_wire(out, *wires)
+	n.gates = append(n.gates, &Gate{in: in,
+		op:  to_operation(op),
+		out: outw})
+}
+
+func (n *Network) OutputKnown() bool {
+	for _, gate := range n.gates {
+		if gate.out.name[0] != 'z' {
+			continue
+		}
+		if gate.out.state == NA {
+			return false
+		}
+	}
+	return true
+}
+
+func (n *Network) Output() int64 {
+	var ret int64
+	ret = 0
+	for _, gate := range n.gates {
+		if gate.out.name[0] != 'z' {
+			continue
+		}
+		addr := utils.MustAtoi(gate.out.name[1:])
+		if gate.out.state == ONE {
+			ret += 1 << addr
+		}
+	}
+	return ret
+}
+
+func (n Gate) String() string {
+	return n.in[0].name + "(" + n.in[0].state.String() + ")\t" + n.op.String() + " " + n.in[1].name + "(" + n.in[1].state.String() + ")\t ->\t" + n.out.name + " (" + n.out.state.String() + ")"
+}
+func to_state(in string) State {
+	switch in {
+	case "1":
+		return ONE
+	case "0":
+		return ZERO
+	}
+	return NA
+}
+
+func to_operation(in string) Operation {
+	var val Operation
+	switch in {
+	case "AND":
+		val = AND
+	case "OR":
+		val = OR
+	case "XOR":
+		val = XOR
+	}
+	return val
+}
+
+func to_wire(in string, wires []*Wire) ([]*Wire, *Wire) {
+	for _, v := range wires {
+		if in == v.name {
+			return wires, v
+		}
+	}
+	wire := Wire{name: in, state: NA}
+	wires = append(wires, &wire)
+	return wires, &wire
+}
+
+func And(a, b State) State {
+	if a == ONE && b == ONE {
+		return ONE
+	}
+	return ZERO
+}
+
+func Or(a, b State) State {
+	if a == ONE || b == ONE {
+		return ONE
+	}
+	return ZERO
+}
+
+func Xor(a, b State) State {
+	if (a == ONE && b == ZERO) || (a == ZERO && b == ONE) {
+		return ONE
+	}
+	return ZERO
+}
+
+func (state State) String() string {
+	switch state {
+	case NA:
+		return "NA"
+	case ZERO:
+		return "0"
+	case ONE:
+		return "1"
+	default:
+		return "Invalid"
+	}
+}
+
+func (op Operation) String() string {
+	switch op {
+	case OR:
+		return "OR"
+	case AND:
+		return "AND"
+	case XOR:
+		return "XOR"
+	default:
+		return "Invalid"
+	}
+}

2024/go/day24/day24_test.go

@@ -0,0 +1,17 @@
+package day24
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1("")
+	require.Equal(t, 0, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2("")
+	require.Equal(t, 0, r)
+}

2024/go/day24/input.txt

@@ -0,0 +1,313 @@
+x00: 1
+x01: 0
+x02: 1
+x03: 1
+x04: 0
+x05: 0
+x06: 1
+x07: 1
+x08: 0
+x09: 1
+x10: 1
+x11: 1
+x12: 1
+x13: 0
+x14: 1
+x15: 1
+x16: 1
+x17: 1
+x18: 1
+x19: 1
+x20: 0
+x21: 1
+x22: 0
+x23: 1
+x24: 0
+x25: 1
+x26: 1
+x27: 1
+x28: 1
+x29: 0
+x30: 0
+x31: 1
+x32: 0
+x33: 1
+x34: 1
+x35: 0
+x36: 0
+x37: 1
+x38: 0
+x39: 1
+x40: 1
+x41: 1
+x42: 1
+x43: 0
+x44: 1
+y00: 1
+y01: 0
+y02: 0
+y03: 1
+y04: 1
+y05: 0
+y06: 0
+y07: 0
+y08: 0
+y09: 0
+y10: 0
+y11: 1
+y12: 0
+y13: 1
+y14: 0
+y15: 1
+y16: 1
+y17: 1
+y18: 1
+y19: 0
+y20: 0
+y21: 1
+y22: 1
+y23: 1
+y24: 1
+y25: 0
+y26: 0
+y27: 1
+y28: 1
+y29: 1
+y30: 1
+y31: 0
+y32: 0
+y33: 0
+y34: 1
+y35: 1
+y36: 1
+y37: 0
+y38: 1
+y39: 1
+y40: 1
+y41: 1
+y42: 0
+y43: 1
+y44: 1
+
+x03 AND y03 -> htr
+gwb AND kvf -> pkd
+x04 AND y04 -> jjm
+qcm XOR twv -> z21
+rrq XOR bmp -> z44
+x43 AND y43 -> pnn
+x06 XOR y06 -> qmt
+x26 AND y26 -> z26
+y00 AND x00 -> whb
+jfq XOR fbb -> z36
+y33 AND x33 -> mmb
+x38 AND y38 -> vqt
+bbh OR qtd -> jfq
+cbs AND ttb -> qtd
+wqs OR cmf -> tpf
+x10 AND y10 -> bfm
+djp OR pfb -> qvr
+x20 XOR y20 -> vhb
+kkd XOR cjg -> z32
+qpp XOR stg -> z41
+kkd AND cjg -> mdv
+tpp OR pfj -> twv
+www AND qdf -> vjf
+y15 XOR x15 -> hmr
+mtg XOR sqm -> z09
+x33 XOR y33 -> chc
+x41 AND y41 -> pkj
+x31 AND y31 -> cvn
+x09 AND y09 -> nvw
+mtg AND sqm -> chg
+pkr AND kcv -> thc
+x07 XOR y07 -> cds
+x15 AND y15 -> fpr
+mwv AND jsg -> wdw
+mwv XOR jsg -> z38
+y16 XOR x16 -> svs
+y14 XOR x14 -> fnq
+wth OR vjf -> btv
+bvp AND gdb -> stc
+cjb XOR rjc -> z04
+x13 AND y13 -> pfb
+x30 AND y30 -> qgf
+htq AND rtk -> dsm
+x18 XOR y18 -> kvf
+y12 AND x12 -> mqn
+bcj XOR bkh -> z03
+x07 AND y07 -> sdj
+bdf OR wbw -> qkf
+y30 XOR x30 -> kbn
+tpf AND vhb -> tpp
+hqd OR fpr -> hgh
+vfm XOR hbw -> z23
+x01 AND y01 -> bdf
+nvw OR chg -> vgp
+x21 XOR y21 -> qcm
+bwg AND mfn -> djp
+dnf OR pkj -> ksp
+y44 AND x44 -> gqr
+y11 AND x11 -> smr
+smr OR dsm -> ksn
+jkm OR pkd -> rjf
+thc OR sqt -> rbd
+qvr XOR fnq -> z14
+cjb AND rjc -> fsb
+svg XOR fmt -> z31
+x06 AND y06 -> ssv
+dtj OR vvq -> jvp
+chv XOR fqf -> z34
+cvr AND hck -> pjd
+dqp AND nbm -> hvv
+x29 AND y29 -> vvq
+y13 XOR x13 -> mfn
+ksn AND nft -> z12
+jjd XOR whb -> z01
+chc AND rnq -> vjh
+y36 AND x36 -> kfn
+cwh OR vvw -> ttb
+qkf AND wsv -> pqc
+rdj OR kfv -> gdb
+x08 AND y08 -> jrr
+x02 AND y02 -> vdf
+x12 XOR y12 -> nft
+ptf OR jrr -> sqm
+tdv OR wjp -> cjw
+qvr AND fnq -> mch
+x28 XOR y28 -> cfj
+gtn XOR qmt -> z06
+mqn OR jpj -> bwg
+x36 XOR y36 -> fbb
+qht OR bfm -> htq
+y42 AND x42 -> mkg
+ksn XOR nft -> jpj
+x20 AND y20 -> pfj
+cmt AND nbq -> gmc
+rbd XOR knm -> z25
+pvj XOR ksp -> z42
+kgj OR stc -> www
+tpf XOR vhb -> z20
+pjd OR dsg -> mwv
+cbs XOR ttb -> z35
+bfk OR jvm -> gwb
+ffj XOR rpg -> z17
+vjr OR kwg -> pkr
+pvj AND ksp -> dkc
+y37 XOR x37 -> cvr
+btv XOR cfj -> z28
+gtq OR qgf -> fmt
+nbq XOR cmt -> z39
+wgq AND dqj -> tws
+x24 AND y24 -> sqt
+whj OR pnn -> bmp
+x02 XOR y02 -> wsv
+stg AND qpp -> dnf
+kbn XOR jvp -> z30
+y39 AND x39 -> gwq
+cds AND rkv -> nph
+kvf XOR gwb -> z18
+mkg OR dkc -> sch
+bqh XOR rjf -> z19
+hck XOR cvr -> z37
+jmk OR ssv -> rkv
+x21 AND y21 -> cgd
+pqc OR vdf -> bkh
+rff OR mts -> rpg
+bkh AND bcj -> rhq
+bnv OR bst -> stg
+bwg XOR mfn -> z13
+sgt AND scc -> bnv
+btv AND cfj -> tdv
+svs AND hgh -> rff
+hbw AND vfm -> kwg
+x40 XOR y40 -> scc
+y17 AND x17 -> jvm
+y34 AND x34 -> chv
+y35 AND x35 -> bbh
+mdv OR rft -> rnq
+fqf AND chv -> cwh
+y28 AND x28 -> wjp
+sch AND srj -> whj
+htr OR rhq -> rjc
+x05 XOR y05 -> dqp
+cvn OR qnk -> cjg
+y14 AND x14 -> tfr
+y11 XOR x11 -> rtk
+jfq AND fbb -> trr
+ppb AND hmr -> hqd
+gtb OR hvv -> gtn
+y44 XOR x44 -> rrq
+rtk XOR htq -> z11
+x01 XOR y01 -> jjd
+hmv XOR rts -> z08
+y10 XOR x10 -> vpc
+jvp AND kbn -> gtq
+cjw AND ntj -> dtj
+x22 AND y22 -> prp
+ppb XOR hmr -> z15
+y18 AND x18 -> jkm
+x39 XOR y39 -> nbq
+jjd AND whb -> wbw
+x34 XOR y34 -> vvw
+x19 AND y19 -> wqs
+gwq OR gmc -> sgt
+rbd AND knm -> rdj
+srj XOR sch -> z43
+y05 AND x05 -> gtb
+x08 XOR y08 -> hmv
+y25 AND x25 -> kfv
+cgd OR jth -> dqj
+vpc XOR vgp -> z10
+tws OR prp -> hbw
+jjm OR fsb -> nbm
+wdw OR vqt -> cmt
+rrq AND bmp -> cbv
+rts AND hmv -> ptf
+svs XOR hgh -> z16
+y41 XOR x41 -> qpp
+ntj XOR cjw -> z29
+ffj AND rpg -> bfk
+gqr OR cbv -> z45
+x25 XOR y25 -> knm
+chc XOR rnq -> z33
+y43 XOR x43 -> srj
+vgp AND vpc -> qht
+x00 XOR y00 -> z00
+cds XOR rkv -> rts
+x24 XOR y24 -> kcv
+x32 AND y32 -> rft
+nbm XOR dqp -> z05
+x35 XOR y35 -> cbs
+mch OR tfr -> ppb
+x16 AND y16 -> mts
+www XOR qdf -> z27
+x23 AND y23 -> vjr
+x26 XOR y26 -> bvp
+gtn AND qmt -> jmk
+x29 XOR y29 -> ntj
+y19 XOR x19 -> bqh
+rjf AND bqh -> cmf
+y38 XOR x38 -> jsg
+x32 XOR y32 -> kkd
+y03 XOR x03 -> bcj
+y31 XOR x31 -> svg
+y22 XOR x22 -> wgq
+qkf XOR wsv -> z02
+bvp XOR gdb -> kgj
+x04 XOR y04 -> cjb
+x17 XOR y17 -> ffj
+y37 AND x37 -> dsg
+y27 AND x27 -> wth
+y23 XOR x23 -> vfm
+sgt XOR scc -> z40
+mmb OR vjh -> fqf
+qcm AND twv -> jth
+y09 XOR x09 -> mtg
+sdj OR nph -> z07
+wgq XOR dqj -> z22
+trr OR kfn -> hck
+y27 XOR x27 -> qdf
+kcv XOR pkr -> z24
+x42 XOR y42 -> pvj
+x40 AND y40 -> bst
+svg AND fmt -> qnk

2024/go/day25/day25.go

@@ -0,0 +1,76 @@
+package day25
+
+import (
+	"fmt"
+	"strings"
+	"math"
+)
+
+type Lock struct {
+	diagram string
+	combination int
+}
+
+type Key struct {
+	diagram string
+	combination int
+}
+
+type Pair struct {
+	l Lock
+	k Key
+}
+
+func Part1(input string) int {
+	data := strings.Split(input, "\n\n")
+	locks := make([]Lock, 0)
+	keys := make([]Key, 0)
+	pairs := make([]Pair, 0)
+
+	for _, in := range data {
+		if in[0] == '#' {
+			locks = append(locks, Lock{diagram: in, combination: combination(in, '.')  })
+		} else {
+			keys = append(keys, Key{diagram: in, combination: combination(in, '#')})
+		}
+	}
+	
+	for _, l := range locks {
+		for _, k := range keys {
+			if key_fits(l.combination, k.combination) {
+				pairs = append(pairs, Pair{l: l, k: k})
+			}
+		}
+	}
+	fmt.Printf("locks: %d, keys: %d\n", len(locks), len(keys))
+	fmt.Printf("pair0 lock\n%s\n%d\n", pairs[0].l.diagram , pairs[0].l.combination)
+	fmt.Printf("pair0 key\n%s\n%d\n",pairs[0].k.diagram, pairs[0].k.combination)
+	return len(pairs)
+}
+
+func Part2(input string) int {
+	return 0
+}
+
+func combination(d string, k rune) int {
+	comb := 0
+	rows := strings.Split(d, "\n")
+	columns := len(rows[0])
+	for _, r := range rows {
+		for i, c := range r {
+			if c == k {
+				comb += 1 * int(math.Pow10(columns - i - 1))
+			}
+		}
+	}
+	return comb
+}
+
+func key_fits(l int, k int) bool {
+	for i:=1;i<6;i++ {
+		ll := l % int(math.Pow10(i))
+		kk := k % int(math.Pow10(i))
+		if ll  < kk { return false }
+	}
+	return true
+}

2024/go/day25/day25_test.go

@@ -0,0 +1,24 @@
+package day25
+
+import (
+	"log"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	data, err := os.ReadFile("input.txt")
+	if err != nil {
+		log.Fatalf("failed to read file: %s", err)
+	}
+
+	r := Part1(string(data))
+	require.Equal(t, 0, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2("")
+	require.Equal(t, 0, r)
+}

2024/go/go.mod

@@ -1,15 +1,14 @@
 module adventofcode2024
 
-go 1.19
+go 1.23.2
+
+toolchain go1.23.5
 
 require (
 	github.com/deckarep/golang-set/v2 v2.7.0
-	github.com/luxedo/esb_fireplace-go v0.3.0
 	golang.org/x/exp v0.0.0-20241009180824-f66d83c29e7c
 )
 
-require github.com/spf13/pflag v1.0.5 // indirect
-
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect

2024/go/go.sum

@@ -2,12 +2,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/deckarep/golang-set/v2 v2.7.0 h1:gIloKvD7yH2oip4VLhsv3JyLLFnC0Y2mlusgcvJYW5k=
 github.com/deckarep/golang-set/v2 v2.7.0/go.mod h1:VAky9rY/yGXJOLEDv3OMci+7wtDpOF4IN+y82NBOac4=
-github.com/luxedo/esb_fireplace-go v0.3.0 h1:zhpWG9AJfWEzqiaYsPjlBAwIMa1IF1gWoQoM4zvdLxI=
-github.com/luxedo/esb_fireplace-go v0.3.0/go.mod h1:L8zIvYDHIKTHc3g3VACvjS0qBHvKmt31KRjWLP5ftkU=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
-github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 golang.org/x/exp v0.0.0-20241009180824-f66d83c29e7c h1:7dEasQXItcW1xKJ2+gg5VOiBnqWrJc+rq0DPKyvvdbY=

2024/go/main.go

@@ -26,6 +26,11 @@ import (
 	"adventofcode2024/day17"
 	"adventofcode2024/day18"
 	"adventofcode2024/day19"
+	"adventofcode2024/day21"
+	"adventofcode2024/day22"
+	"adventofcode2024/day23"
+	"adventofcode2024/day24"
+	"adventofcode2024/day25"
 	"adventofcode2024/utils"
 )
 
@@ -90,6 +95,21 @@ func main() {
 	case 19:
 		fmt.Printf("part 1: %d\n", day19.Part1(utils.Readfile(d)))
 		fmt.Printf("part 2: %d\n", day19.Part2(utils.Readfile(d)))
+	case 21:
+		fmt.Printf("part 1: %d\n", day21.Part1(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day21.Part2(utils.Readfile(d)))
+	case 22:
+		fmt.Printf("part 1: %d\n", day22.Part1(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day22.Part2(utils.Readfile(d)))
+	case 23:
+		fmt.Printf("part 1: %d\n", day23.Part1(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day23.Part2(utils.Readfile(d)))
+	case 24:
+		fmt.Printf("part 1: %d\n", day24.Part1(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day24.Part2(utils.Readfile(d)))
+	case 25:
+		fmt.Printf("part 1: %d\n", day25.Part1(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day25.Part2(utils.Readfile(d)))
 	default:
 		panic(fmt.Errorf("no such day: %d", d))
 	}
@@ -99,7 +119,7 @@ func main() {
 
 // Reads day from os.Args.
 func day() int {
-	latest := 19
+	latest := 24
 	if len(os.Args) == 1 {
 		return latest
 	}

2024/go/utils/dijkstra/graph.go

@@ -1,7 +1,6 @@
 package dijkstra
 
 import (
-	"fmt"
 	"math"
 	"sync"
 )
@@ -92,7 +91,7 @@ func getShortestPath(startNode *Node, endNode *Node, g *ItemGraph) ([]Point, int
 		pathval = prev[pathval]
 	}
 	finalArr = append(finalArr, pathval)
-	fmt.Println(finalArr)
+	//	fmt.Println(finalArr)
 	for i, j := 0, len(finalArr)-1; i < j; i, j = i+1, j-1 {
 		finalArr[i], finalArr[j] = finalArr[j], finalArr[i]
 	}

2024/go/utils/memo/memo.go

@@ -0,0 +1,47 @@
+package memo
+
+import "sync"
+
+type Func func(key interface{}) interface{}
+
+type result struct {
+	value interface{}
+}
+
+type Memo struct {
+	f     Func
+	cache map[interface{}]result
+	mu    sync.RWMutex // Allows concurrent reads.
+}
+
+func New(f Func) *Memo {
+	return &Memo{
+		f:     f,
+		cache: make(map[interface{}]result),
+	}
+}
+
+func (memo *Memo) Get(key interface{}) interface{} {
+	// First, try to read the cache using a read lock.
+	memo.mu.RLock()
+	res, ok := memo.cache[key]
+	memo.mu.RUnlock()
+	if ok {
+		return res.value
+	}
+
+	// Compute the result without holding the lock.
+	computed := memo.f(key)
+
+	// Now acquire a write lock to update the cache.
+	memo.mu.Lock()
+	// Double-check: another goroutine may have stored the result in the meantime.
+	res, ok = memo.cache[key]
+	if !ok {
+		res.value = computed
+		memo.cache[key] = res
+	}
+	memo.mu.Unlock()
+
+	return res.value
+}

2024/go/utils/ringbuffer/ringbuffer.go

@@ -0,0 +1,56 @@
+package ringbuffer
+
+import (
+	"sync"
+)
+
+type RingBuffer[T any] struct {
+	buffer []T
+	size   int
+	mu     sync.Mutex
+	write  int
+	count  int
+}
+
+// NewRingBuffer creates a new ring buffer with a fixed size.
+func NewRingBuffer[T any](size int) *RingBuffer[T] {
+	return &RingBuffer[T]{
+		buffer: make([]T, size),
+		size:   size,
+	}
+}
+
+// Add inserts a new element into the buffer, overwriting the oldest if full.
+func (rb *RingBuffer[T]) Add(value T) {
+	rb.mu.Lock()
+	defer rb.mu.Unlock()
+
+	rb.buffer[rb.write] = value
+	rb.write = (rb.write + 1) % rb.size
+
+	if rb.count < rb.size {
+		rb.count++
+	}
+}
+
+// Get returns the contents of the buffer in FIFO order.
+func (rb *RingBuffer[T]) Get() []T {
+	rb.mu.Lock()
+	defer rb.mu.Unlock()
+
+	result := make([]T, 0, rb.count)
+
+	for i := 0; i < rb.count; i++ {
+		index := (rb.write + rb.size - rb.count + i) % rb.size
+		result = append(result, rb.buffer[index])
+	}
+
+	return result
+}
+
+// Len returns the current number of elements in the buffer.
+func (rb *RingBuffer[T]) Len() int {
+	rb.mu.Lock()
+	defer rb.mu.Unlock()
+	return rb.count
+}

2025/gareth/day01/day01.go

@@ -0,0 +1,64 @@
+package day01
+
+import (
+	"strconv"
+	"strings"
+)
+
+func Part1(input string) int {
+	lines := strings.Split(input, "\n")
+
+	position := 50
+	output := 0
+
+	for _, line := range lines {
+		direction := line[0]
+		amount, _ := strconv.Atoi(line[1:])
+
+		if direction == 'R' {
+			position += amount
+			for position > 99 {
+				position -= 100
+			}
+		} else if direction == 'L' {
+			position -= amount
+			for position < 0 {
+				position += 100
+			}
+		}
+
+		if position == 0 {
+			output++
+		}
+	}
+
+	return output
+}
+
+func Part2(input string) int {
+	lines := strings.Split(input, "\n")
+	position := 50
+	output := 0
+
+	for _, line := range lines {
+		direction := line[0]
+		amount, _ := strconv.Atoi(line[1:])
+
+		step := 1
+		if direction == 'L' {
+			step = -1
+		}
+
+		for i := 0; i < amount; i++ {
+			position = (position + step) % 100
+			if position < 0 {
+				position += 100
+			}
+			if position == 0 {
+				output++
+			}
+		}
+	}
+
+	return output
+}

2025/gareth/day01/day01_test.go

@@ -0,0 +1,35 @@
+package day01
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82`)
+	assert.Equal(t, 3, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82`)
+	assert.Equal(t, 6, r)
+}

2025/gareth/day01/poc.py

@@ -0,0 +1,49 @@
+def part1(input_file):
+    file = open(input_file, "r")
+    line = file.readline()
+
+    position = 50
+    output = 0
+    while line:
+        direction = line[0]
+        amount = int(line[1:])
+
+        if direction == "R":
+            position += amount
+            while position > 99:
+                position -= 100
+
+        elif direction == "L":
+            position -= amount
+            while position < 0:
+                position += 100
+
+        if position == 0:
+            output += 1
+
+        line = file.readline()
+
+    file.close()
+    print("Part 1:", output)
+
+def part2(input_file):
+    position = 50
+    output = 0
+
+    with open(input_file) as file:
+        for line in file:
+            line = line.strip()
+            direction = line[0]
+            amount = int(line[1:])
+
+            step = 1 if direction == "R" else -1
+
+            for _ in range(amount):
+                position = (position + step) % 100
+                if position == 0:
+                    output += 1
+
+    print("Part 2:", output)
+
+part1("input.txt")
+part2("input.txt")

2025/gareth/day02/day02.go

@@ -0,0 +1,119 @@
+package day02
+
+import (
+	"math"
+	"strconv"
+	"strings"
+)
+
+// Very messy and not my finest work but not too bad for 6am
+
+func parseInput(input string) [][2]int {
+	var ranges [][2]int
+	lines := strings.Split(strings.TrimSpace(input), ",")
+	for _, part := range lines {
+		if part == "" {
+			continue
+		}
+		ab := strings.Split(part, "-")
+		if len(ab) != 2 {
+			continue
+		}
+
+		a, _ := strconv.Atoi(ab[0])
+		b, _ := strconv.Atoi(ab[1])
+		ranges = append(ranges, [2]int{a, b})
+	}
+	return ranges
+}
+
+func divisors(n int) []int {
+	out := make([]int, 0)
+	for i := 1; i <= n; i++ {
+		if n%i == 0 {
+			out = append(out, i)
+		}
+	}
+	return out
+}
+
+func Part1(input string) int {
+	ranges := parseInput(input)
+	invalidSum := 0
+
+	for _, r := range ranges {
+		low, high := r[0], r[1]
+
+		minLen := len(strconv.Itoa(low))
+		maxLen := len(strconv.Itoa(high))
+
+		for digits := minLen; digits <= maxLen; digits++ {
+			if digits%2 != 0 {
+				continue
+			}
+
+			half := digits / 2
+			start := int(math.Pow(10, float64(half-1)))
+			end := int(math.Pow(10, float64(half)))
+
+			for first := start; first < end; first++ {
+				s := strconv.Itoa(first)
+				selected, _ := strconv.Atoi(s + s)
+
+				if selected < low {
+					continue
+				}
+				if selected > high {
+					break
+				}
+
+				invalidSum += selected
+			}
+		}
+	}
+
+	return invalidSum
+}
+
+func Part2(input string) int {
+	ranges := parseInput(input)
+	total := 0
+
+	for _, r := range ranges {
+		low, high := r[0], r[1]
+		seen := make(map[int]bool)
+
+		minLen := len(strconv.Itoa(low))
+		maxLen := len(strconv.Itoa(high))
+
+		for d := minLen; d <= maxLen; d++ {
+			for _, L := range divisors(d) {
+				k := d / L
+				if k < 2 {
+					continue
+				}
+				start := int(math.Pow(10, float64(L-1)))
+				end := int(math.Pow(10, float64(L)))
+
+				for base := start; base < end; base++ {
+					s := strings.Repeat(strconv.Itoa(base), k)
+					selected, _ := strconv.Atoi(s)
+
+					if selected < low {
+						continue
+					}
+					if selected > high {
+						break
+					}
+
+					if !seen[selected] {
+						seen[selected] = true
+						total += selected
+					}
+				}
+			}
+		}
+	}
+
+	return total
+}

2025/gareth/day02/day02_test.go

@@ -0,0 +1,17 @@
+package day02
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`11-22,95-115,998-1012,1188511880-1188511890,222220-222224,1698522-1698528,446443-446449,38593856-38593862,565653-565659,824824821-824824827,2121212118-2121212124`)
+	assert.Equal(t, 1227775554, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`11-22,95-115,998-1012,1188511880-1188511890,222220-222224,1698522-1698528,446443-446449,38593856-38593862,565653-565659,824824821-824824827,2121212118-2121212124`)
+	assert.Equal(t, 4174379265, r)
+}

2025/gareth/day02/input.txt

@@ -0,0 +1 @@
+78847-119454,636-933,7143759788-7143793713,9960235-10043487,44480-68595,23468-43311,89-123,785189-1014654,3829443354-3829647366,647009-692765,2-20,30-42,120909-197026,5477469-5677783,9191900808-9191943802,1045643-1169377,46347154-46441299,2349460-2379599,719196-779497,483556-641804,265244-450847,210541-230207,195-275,75702340-75883143,58-84,2152-3237,3367-5895,1552-2029,9575-13844,6048-8966,419388311-419470147,936-1409,9292901468-9292987321

2025/gareth/day03/dad_in.txt

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2025/gareth/day03/dad_out.txt

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2025/gareth/day03/day03.go

@@ -0,0 +1,69 @@
+package day03
+
+import (
+	"strconv"
+	"strings"
+)
+
+func Part1(input string) int {
+	lines := strings.Split(input, "\n")
+	output := 0
+
+	for _, bank := range lines {
+		best := 0
+		length := len(bank)
+		for i := 0; i < length; i++ {
+			tens, _ := strconv.Atoi(string(bank[i]))
+			for j := i + 1; j < length; j++ {
+				ones, _ := strconv.Atoi(string(bank[j]))
+				value := tens*10 + ones
+				if value > best {
+					best = value
+				}
+			}
+		}
+		output += best
+	}
+
+	return output
+}
+
+func Part2(input string) int {
+	lines := strings.Split(strings.TrimSpace(input), "\n")
+	total := 0
+	k := 12
+
+	for _, bank := range lines {
+		bank = strings.TrimSpace(bank)
+
+		n := len(bank)
+		start := 0
+		chosen := make([]byte, 0, k)
+
+		for picked := 0; picked < k; picked++ {
+			// leave enough digits to complete the subsequence
+			last := n - (k - picked)
+			bestChar := bank[start]
+			bestIdx := start
+
+			for i := start + 1; i <= last; i++ {
+				if bank[i] > bestChar {
+					bestChar = bank[i]
+					bestIdx = i
+
+					if bestChar == '9' {
+						break
+					}
+				}
+			}
+
+			chosen = append(chosen, bestChar)
+			start = bestIdx + 1
+		}
+
+		val, _ := strconv.Atoi(string(chosen))
+		total += val
+	}
+
+	return total
+}

2025/gareth/day03/day03_test.go

@@ -0,0 +1,23 @@
+package day03
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`987654321111111
+811111111111119
+234234234234278
+818181911112111`)
+	assert.Equal(t, 357, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`987654321111111
+811111111111119
+234234234234278
+818181911112111`)
+	assert.Equal(t, 3121910778619, r)
+}

2025/gareth/day03/greatest_and_most_modest_coder_ever_out.txt

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2025/gareth/day03/poc.py

@@ -0,0 +1,58 @@
+def part1(input_str):
+    lines = input_str.strip().split("\n")
+    output = 0
+
+    for bank in lines:
+        best = 0
+        length = len(bank)
+
+        for i in range(length):
+            tens = int(bank[i])
+            for j in range(i + 1, length):
+                ones = int(bank[j])
+                value = tens * 10 + ones
+                if value > best:
+                    best = value
+
+        output += best
+
+    return output
+
+
+def part2(input_str, k = 12):
+    lines = input_str.strip().split("\n")
+    total = 0
+
+    for bank in lines:
+        bank = bank.strip()
+        n = len(bank)
+        start = 0
+        chosen = []
+
+        for picked in range(k):
+            last = n - (k - picked)
+            best_char = bank[start]
+            best_idx = start
+
+            for i in range(start + 1, last + 1):
+                if bank[i] > best_char:
+                    best_char = bank[i]
+                    best_idx = i
+
+                    if best_char == '9':
+                        break
+
+            chosen.append(best_char)
+            start = best_idx + 1
+
+        total += int("".join(chosen))
+
+    return total
+
+
+
+with open("input.txt") as f:
+    data = f.read()
+
+print("Part1:", part1(data))
+print("Part2:", part2(data, 12))

2025/gareth/go.mod

@@ -0,0 +1,11 @@
+module aoc/2025
+
+go 1.23.2
+
+require github.com/stretchr/testify v1.11.1
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

2025/gareth/go.sum

@@ -0,0 +1,9 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

2025/gareth/main.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"aoc/2025/day02"
+	"fmt"
+	"os"
+	"time"
+)
+
+func main() {
+	start := time.Now()
+	data, _ := os.ReadFile("day02/input.txt")
+	fmt.Printf("part 1: %d\n", day02.Part1(string(data)))
+	fmt.Printf("part 2: %d\n", day02.Part2(string(data)))
+	elapsed := time.Since(start)
+	fmt.Printf("Execution time: %s\n", elapsed)
+}

2025/go/.vscode/launch.json

@@ -0,0 +1,16 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch Package",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${fileDirname}",
+            "args": ["1"]
+        }
+    ]
+}

2025/go/day01/day01.go

@@ -0,0 +1,128 @@
+package day01
+
+import (
+	"adventofcode2025/utils"
+	"fmt"
+	"strings"
+)
+
+type Dir int
+
+const (
+	Left Dir = iota
+	Right
+	Safe
+	Unsafe
+)
+
+type Instruction struct {
+	Turn  Dir
+	Steps int
+}
+
+func Part1(input string) int {
+	lines := strings.Split(input, "\n")
+	position := 50
+	code := 0
+	Instructions := make([]Instruction, 0)
+	for _, line := range lines {
+		var steps int
+		var dir Dir
+		switch line[0] {
+		case 'L':
+			steps = utils.MustAtoi(line[1:])
+			dir = Left
+		case 'R':
+			steps = utils.MustAtoi(line[1:])
+			dir = Right
+		default:
+			fmt.Println("Invalid direction")
+			continue
+		}
+		if steps > 100 {
+			steps = steps % 100
+		}
+		Instructions = append(Instructions, Instruction{Turn: dir, Steps: steps})
+	}
+	fmt.Print(Instructions)
+	for _, instr := range Instructions {
+		if instr.Turn == Left {
+			if position-instr.Steps < 0 {
+				position = 100 + (position - instr.Steps)
+			} else {
+				position -= instr.Steps
+			}
+		} else if instr.Turn == Right {
+			if position+instr.Steps >= 100 {
+				position = (position + instr.Steps) - 100
+			} else {
+				position += instr.Steps
+			}
+		}
+		fmt.Println("\n", instr.Turn, instr.Steps, "->", position)
+		if position == 0 {
+			code++
+		}
+	}
+	return code
+}
+
+func Part2(input string) int {
+	lines := strings.Split(input, "\n")
+	position := 50
+	code := 0
+	Instructions := make([]Instruction, 0)
+	for _, line := range lines {
+		var steps int
+		var dir Dir
+		switch line[0] {
+		case 'L':
+			steps = utils.MustAtoi(line[1:])
+			dir = Left
+		case 'R':
+			steps = utils.MustAtoi(line[1:])
+			dir = Right
+		default:
+			fmt.Println("Invalid direction")
+			continue
+		}
+		Instructions = append(Instructions, Instruction{Turn: dir, Steps: steps})
+	}
+	fmt.Print(Instructions)
+	for _, instr := range Instructions {
+		if instr.Steps > 100 {
+			code = code + (instr.Steps / 100)
+			instr.Steps = instr.Steps % 100
+		}
+		if instr.Turn == Left {
+			if position-instr.Steps < 0 {
+				if position != 0 {
+					code++
+				}
+				position = 100 + (position - instr.Steps)
+				
+			} else {
+				position -= instr.Steps
+				if position == 0 {
+					code++
+				}
+			}
+		} else if instr.Turn == Right {
+			if position+instr.Steps > 99 {
+				if position != 0 {
+					code++
+				}
+				position = (position + instr.Steps) - 100
+			} else {
+				position += instr.Steps
+				if position == 0 {
+					code++
+				}
+			}
+		}
+
+		fmt.Println("\n", instr.Turn, instr.Steps, "->", position, "code:", code)
+
+	}
+	return code
+}

2025/go/day01/day01_test.go

@@ -0,0 +1,34 @@
+package day01
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require")
+
+func TestPart1(t *testing.T) {
+	r := Part1(`L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82`)
+	require.Equal(t, 3, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82`)
+	require.Equal(t, 6, r)
+}

2025/go/day02/day02.go

@@ -0,0 +1,59 @@
+package day02
+
+import (
+	"adventofcode2025/utils"
+	"fmt"
+	"strings"
+)
+
+func Part1(input string) int {
+	ranges := strings.Split(input, ",")
+	count := 0
+	for _, r := range ranges {
+		min_s, max_s := strings.Split(r, "-")[0], strings.Split(r, "-")[1]
+		min := utils.MustAtoi(min_s)
+		max := utils.MustAtoi(max_s)
+		for i := min; i <= max; i++ {
+			s := fmt.Sprintf("%d", i)
+			if len(s)%2 != 0 {
+				continue
+			}
+			if s[:len(s)/2] != s[len(s)/2:] {
+				continue
+			}
+			count += utils.MustAtoi(s)
+		}
+	}
+	return count
+}
+
+func Part2(input string) int {
+	ranges := strings.Split(input, ",")
+	count := 0
+	for _, r := range ranges {
+		min_s, max_s := strings.Split(r, "-")[0], strings.Split(r, "-")[1]
+		min := utils.MustAtoi(min_s)
+		max := utils.MustAtoi(max_s)
+		for i := min; i <= max; i++ {
+			s := fmt.Sprintf("%d", i)
+			for numDigits := 1; numDigits <= len(s)/2; numDigits++ {
+				if len(s)%numDigits != 0 {
+					continue
+				}
+				found := true
+				for j := 1; j < len(s)/numDigits; j++ {
+					if s[0:numDigits] != s[j*numDigits:(j+1)*numDigits] {
+						found = false
+						continue
+					}
+
+				}
+				if found {
+					count += utils.MustAtoi(s)
+					break
+				}
+			}
+		}
+	}
+	return count
+}

2025/go/day03/day03.go

@@ -0,0 +1,68 @@
+package day03
+
+import (
+	"adventofcode2025/utils"
+	"fmt"
+	"strings"
+)
+
+const NUM_OF_CELLS = 12
+
+func Part1(input string) int {
+	var jolts []int
+	batteries := strings.Split(input, "\n")
+	for _, battery := range batteries {
+		maxJolt := 0
+		cells := strings.Split(battery, "")
+		for i := 0; i < len(cells)-1; i++ {
+			for j := i + 1; j < len(cells); j++ {
+				jolt := utils.MustAtoi(fmt.Sprintf("%s%s", cells[i], cells[j]))
+				if jolt > maxJolt {
+					maxJolt = jolt
+				}
+			}
+		}
+		jolts = append(jolts, maxJolt)
+	}
+	sum := 0
+	for _, jolt := range jolts {
+		sum += jolt
+	}
+	return sum
+}
+
+func Part2(input string) int {
+	var jolts []string
+	batteries := strings.Split(input, "\n")
+	for _, battery := range batteries {
+		start := 0
+		end := len(battery) - NUM_OF_CELLS
+		j := ""
+		for i := 0; i < NUM_OF_CELLS; i++ {
+			v, pos := find_first_max(battery[start : end+1])
+			j = j + v
+			start = start + pos + 1
+			end = len(battery) - NUM_OF_CELLS + i + 1
+		}
+		jolts = append(jolts, j)
+	}
+	sum := 0
+	for _, jolt := range jolts {
+		fmt.Println(jolt)
+		sum += utils.MustAtoi(jolt)
+	}
+	return sum
+}
+
+func find_first_max(s string) (string, int) {
+	max := byte('0')
+	pos := -1
+	for i := 0; i < len(s); i++ {
+		t1 := s[i]
+		if t1 > max {
+			max = s[i]
+			pos = i
+		}
+	}
+	return string(max), pos
+}

2025/go/day03/day03_test.go

@@ -0,0 +1,20 @@
+package day03
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`987654321111111
+811111111111119
+234234234234278
+818181911112111`)
+	require.Equal(t, 357, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`7455526631444542356445533352351453423842653536563363453344445222432533133425443346642463393231542655`)
+	require.Equal(t, 893231542655, r)
+}

2025/go/day03/input.txt

@@ -0,0 +1,200 @@
+3238233422322723245312524333415334121333413432322532233243267325442232433333224143383436222223233233
+3655644666946277273684457436668666955664663983765757454464876854654654857865665766676664954456576457
+2222222214221321222242232252322221422222222212122123221322623222234222422221122212282121422123326322
+2124214643322332212222134232222223323244234222412424222132142344221221232224211124244142332242234423
+3436232236223426333625431396643366362565194162563644533454346253234235616323362232354352264323633232
+5222522242424132416252524213114222342315134433221233322222231246224242332433133211133213224152222532
+5426122223223222711223433222337222332222222833232224339146332213332173223213812332213383222132234312
+6754666344575335444575875747453663683596555517664555664546484534645635645553474345756556566654566656
+5433475435554344344375445374544445355635555544744477536637334335232664335527685544454753243246465444
+2533323723332334421324325274334254525431339343344558454433386313383333342332322853233331232763541433
+3434243341345332224133423322532152471432322626222426413335421225224211233163443935254725234333133342
+3541448771235152323243338633424215242426556266442614844233795554292323321243648444233424278324436324
+4232241923231442232233522224233222222232431222432321223233222123223234123233322133322222222322224341
+2322413333333323433423333323333431233331323233463333343333223323333323333323323333333332354333332133
+2212425414842355412223552127242426224852234212232212232222255523322321224232222232323222235222434633
+2222323222221122221215238122312222122214221322215512242233212223122222232412233122321222222271322222
+5215532261853227652345746126415532422366821723536247423754252265364642376432522655527226425574722471
+3222222422252332112231224221356222221223222134222221232223313326222222131432222522333222223122622222
+6676222427665466767653734672313657732795538736586768869694693597677586674659542276554762257672793343
+3653535256345253634345457434518545543444445544575534454455644555557475445545334555545353535563446555
+2233222222323144222222444222122411422321222212315431213323242223222222242233222224322232221212242531
+3424593117244244313425222742513498752244424152632323419112114524386212455225243275425565524227362317
+5531424542533424455635625443656442662633435324445245422523346364263544533554433452426246313433372514
+2522967564465922868445536669545363547885536537774684644666145884654894493744892656428549864924265585
+8736457373466777928237878853455465677654727936757338659679873668786246374673877537787726887267376752
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2025/go/day04/day04.go

@@ -0,0 +1,92 @@
+package day04
+
+import (
+	"adventofcode2025/utils/grid2d"
+	"adventofcode2025/utils/inputs"
+)
+
+func Part1(input string) int {
+	adj := 0
+	rolls := 0
+	grid := inputs.ToGrid2D(input, "\n", "", "", func(c string) string { return c })
+	directions := [][]int{{0, 1}, {0, -1}, {1, 0}, {-1, 0}, {-1, 1}, {1, 1}, {-1, -1}, {1, -1}}
+	for j := 0; j < grid.SizeY(); j++ {
+		for i := 0; i < grid.SizeX(); i++ {
+			if !checkChar(i, j, grid, "@") {
+				continue
+			}
+			for _, dir := range directions {
+				x := i + dir[0]
+				y := j + dir[1]
+				if checkChar(x, y, grid, "@") {
+					adj++
+				}
+			}
+			if adj < 4 {
+				rolls++
+			}
+			adj = 0
+		}
+	}
+	return rolls
+}
+
+func Part2(input string) int {
+	grid := inputs.ToGrid2D(input, "\n", "", "", func(c string) string { return c })
+	rolls := countRolls(grid)
+	total := rolls
+
+	for rolls > 0 {
+		removeRolls(grid)        // modifies grid
+		rolls = countRolls(grid) // compute only once per loop
+		total += rolls
+	}
+
+	return total
+}
+
+func checkChar(x int, y int, grid *grid2d.Grid[string], c string) bool {
+	if x < 0 || x >= grid.SizeX() || y < 0 || y >= grid.SizeY() {
+		return false
+	}
+	if grid.Get(x, y) == c {
+		return true
+	}
+	return false
+}
+
+func countRolls(grid *grid2d.Grid[string]) int {
+	adj := 0
+	rolls := 0
+	directions := [][]int{{0, 1}, {0, -1}, {1, 0}, {-1, 0}, {-1, 1}, {1, 1}, {-1, -1}, {1, -1}}
+	for j := 0; j < grid.SizeY(); j++ {
+		for i := 0; i < grid.SizeX(); i++ {
+			if checkChar(i, j, grid, ".") {
+				continue
+			}
+			for _, dir := range directions {
+				x := i + dir[0]
+				y := j + dir[1]
+				if checkChar(x, y, grid, "@") || checkChar(x, y, grid, "x") {
+					adj++
+				}
+			}
+			if adj < 4 {
+				grid.Set(i, j, "x")
+				rolls++
+			}
+			adj = 0
+		}
+	}
+	return rolls
+}
+func removeRolls(grid *grid2d.Grid[string]) {
+	for j := 0; j < grid.SizeY(); j++ {
+		for i := 0; i < grid.SizeX(); i++ {
+			if checkChar(i, j, grid, "x") {
+				grid.Set(i, j, ".")
+			}
+		}
+	}
+
+}

2025/go/day04/day04_test.go

@@ -0,0 +1,35 @@
+package day04
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(`..@@.@@@@.
+@@@.@.@.@@
+@@@@@.@.@@
+@.@@@@..@.
+@@.@@@@.@@
+.@@@@@@@.@
+.@.@.@.@@@
+@.@@@.@@@@
+.@@@@@@@@.
+@.@.@@@.@.`)
+	require.Equal(t, 13, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`..@@.@@@@.
+@@@.@.@.@@
+@@@@@.@.@@
+@.@@@@..@.
+@@.@@@@.@@
+.@@@@@@@.@
+.@.@.@.@@@
+@.@@@.@@@@
+.@@@@@@@@.
+@.@.@@@.@.`)
+	require.Equal(t, 43, r)
+}

2025/go/day04/input.txt

@@ -0,0 +1,140 @@
+@@@@@@@@@.@@@@@@@@@.@.@..@@..@@.@.@@.@@.@@@@@@..@@..@.@.@@..@.@.@@@@@.@@.@@@@@@..@@@@@@@....@@@@@@@@.@.@.@@@@@@@@@@.@..@@@@@@@@@@@@@@@@.@.@@
+@@@.@@@.@@@@@@..@..@@@@.@.@.@.@@@@.@.@@@@@@@..@@.@@.@.@@@@.@@@@@@.@@@@.@.@@@...@@.@@@@@@.@.@@@.@.@@@@@.@@@@@@@.@@.@@@@@@@@.@..@@@@.@@@@@@.@@
+@@..@@.@@@.@@@@..@@..@..@@@@@@.@.@@..@@@@....@@@@@@.@.@@.@..@@@@@.@@@@.@@@@@..@@@.@@.@@.@@..@@@@@@@@.@@@@.@@@.@@@@@@@@@@.@@.@@@@.@@@..@@@.@@
+@...@@.@...@@@@@@.@@..@@@@@@@.@...@@@@.@.@@...@@@.@@@@@@.@@@.@@@.@.@..@@@@@@@@.@.@@@@..@@@.....@.@@@@..@...@.@@@@@..@@@.@@@.@@....@.@@@...@.
+..@@@@@.@.@@.@@@..@@@@@@.@@@.@@@@.@@@@.@...@@@@@...@.@@@..@..@..@.@.@.@@@@..@....@@@...@@@@@.@@.@@.@..@.@@@..@@@@@@@@..@.@.@@.@@@..@@@..@@@@
+@@@.@@..@@.@@@..@@.....@@...@@@.@.@@@@@.@@@@..@.@@@@.@.@@@@@@.....@@.@@.@..@@@@@@@..@@.@@..@@@@.@@@.@..@@@.@@@@.@@@.@@@.@@@@@@..@@@@@@.@.@..
+.@@@@.@.@..@.@@@@...@.@..@.@@@.@..@.@...@@@.@@..@..@...@@@..@@@@.@@@.@@@.@@@@.@.@...@@@@.@..@@@.@@..@.@.@@...@.@@.@.@@.@.@.@@@@.@@..@@@@.@@.
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+@@.@..@.@@@@@@@@.@.@@@@@.@.@.@@.@@@.@@@@@@@.@@@@@..@@@@.@@@@@@..@@@@@@..@.@.@@@.@@@@.@.@@.@@@.@@@@.@.@@...@@@@@@@.@@..@@@@.@@@.@@@.@@@@@..@@
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+.@@@.@@.@@@..@..@@.@.@@@@@@.@.@.@@@@.@@@@@@@@..@.@@@@@@@@.@@@@@@@@@@.@@.@@@...@@.@@@@@@@.@@@.@..@@.@....@@.@@...@@.@@..@.@..@@@@..@.@@@.@..@
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+..@.@@@..@@@@.@@@@..@@.@@....@@@@.....@.@.@@@.@.@@@.@@@@@...@@@@@@.@@@@@..@@.@@..@@@.@..@.@....@@@.@.@.@.@@.@@@@@@@.@@@@@@@@.@.@.@@@..@..@.@
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+.@@.@@.@@@@@@@.@@@@@@.@@.@.@@@.@@..@.@@.@.@@@@@@.@@@.@@@@@@@@.@....@@@@@@..@...@.@.@@@@@@@.@.@@@@.@.@@@@.@@@....@@@@@@.@@@@@@@@@.@@@.@@@@@@.
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+.@@@@@@.@@@.@@.@@@..@@.@@@@@@@.....@@@@.@@@@@@@@.....@.@@@.@@@@@@@..@.@@@@..@@.@....@.@.@.@@@@@@@@.@..@..@..@@@@..@@...@@@.@@@@..@@@@..@@@@.
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+@@@.@.@@.@@.@..@.@.@@@@.@.@@...@@.@.@.@@@@@...@@@@.@@.@@@..@@.@@@.@@@.@...@@.@.@@.@@.@@...@@.@@..@@.@.@@@@@@@@.@@...@@@@@@@@@@@.@@..@@@@@@..
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+...@.@.@@.@@@@.@.@@......@.@.@..@@..@@@.@@@@....@@@.@...@.@@.@@@@@@@@@...@@..@.@.@.@@...@@.@@.@...@@.@..@@.@.@....@@..@@.@@@..@@.@.@@@..@@@@
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+..@@@@.@.@@...@@..@@@...@@.@@@@@@@@@@@.@@@..@@@.@@.....@@...@@@.@@.@..@..@@.@.@@@.@.@@@.@.@@@@@.@@.@@@..@@@@@@@@@@..@.@@@@@@@@.@@.@@@@..@@@.
+.@@.@@@@@@..@@@@@.@.@@@@@@@.@@@@..@@.@.@@...@@@...@..@@....@@.@.@@@.@.@@@..@@@.@@...@.@.@@..@@..@@.@@@@@@@@@.@@.@@@@@@@@@@..@.@@@.@.@@@.@@@.
+@.@@.@..@......@@@@@.@@.@@.@@@@@@@@.@.@@.@.@@..@...@...@.@@@.@@@.@@@@@.@..@.@@@@@@@.@@@@@@..@@@@..@@@.@.@@@@..@..@@@@@..@@.@@.@@..@..@@.@@..
+@@.@@.@@@@@@.....@@@.@.@@.@@@@.@.@@..@.@.@@.@@@.@..@.@@.@@@@.@@@@@..@@..@@@...@.@.@@@@..@@@...@@@.@@@@@.@..@@@@@@@@@..@@.@@@@@.@@@@@@..@@.@.
+....@@@@.@....@@@@@@@@..@@@@@@.@..@@@@..@.@@@@..@.@@@@@@@@.@@@@@@@@@@.@@@@@@@@@@@.@.@@@.@.@@.@@.@@@@.@...@@.@@@@@@@@.@@.@.@@..@@@.@.@.@.@.@@
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+.@@@@.@@@.@@@@@@@@@@@@@@.@@@@@@@@..@.@@@@@@@.@@.@@@.@.@@.@@@.@@@@@@.@@@@.@@.@@@@.@.@@.@@@..@@@.@.@@@....@@.@..@@@.@.@@@..@@@@.@@..@.@.@@@@.@
+@@@..@@@@.@@..@@@@@@@@@..@@.@.@.@@@@@@.@@.@@.@@.@.@@@@@.@@..@.@@@.@.@@@@.@@....@@@@.@...@@.@..@@..@..@@@@@@@@.@.@@@.@@.@..@.@..@.@.@@@...@.@
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+.@@@@@.@@@...@@@@.@..@@@..@@..@.@@@@..@........@@@.@@.@@.@.@@@.@@@@...@@@@@@..@@@.@.@...@@.@@.@@.@@@...@.@@@.@@.@.@@.@..@@..@.@@@@@@@@...@@.
+@@@...@@@@@@@@@@....@@@@@.@.@.@..@..@.@@...@.@.@..@@@@.@.....@@.@..@..@...@@@@.@@.@@@@@@@.@@.@@.@@@@.@@@@@.@@.@@.@@@@@.@@@...@@@@@.......@..
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+..@@..@.@@@@@@.@@.@@@@@@@@@.@..@.@.@@..@.@@@@@@@@@@@@.....@.@..@@@...@@@.@@..@@.@@@.@.@@@@@@.@@@....@@.@@..@@.@@@@@.@@..@@.@@@@@@..@@@.@@..@
+@@..@.@.@.@@.@@.@@@@@.@..@@...@.@@@..@@..@@@.@@@..@@.@@@@@@@....@.@@@@@@..@@.@@.@@..@.@@@@@@...@@@@.@@@....@@@..@@..@@..@.@@.@....@@.@.@@@@.
+@...@@.@@@.@.@@@.@.@@@@@@@...@@.@@.@@@..@@@@.@@@.@@@.@.@.@@@@@@.@..@@@@@@@@@@.@@.@.@@.@.@.@@@.@@.@@@..@.@@@.@.@.@@@@..@...@..@@@@.@..@.@.@@.
+..@@@@...@@@.@@.@.@@@@@@@..@@@.@.@@@@@.@@@@@@@@@.@..@@@@@@.@@@.@...@@.@@@@@@@@.@.@.@..@@@@@..@@@.@.@.@@.@@...@.@@....@@@@@.@@@@.@..@..@@@@.@
+.@@.@@...@.@.@..@.@@@@.@@@.@.@.@.@@@..@@@.@@@@@@@@@@@.@.@@@@@.@@@.@.@@.@.@.@.@@.@@@@.@@@.@@@@..@@@@@@@@@@@...@@@@@.@@@@...@...@@.@@.@@.@@.@@
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+@@.@@.@.@@.@@.@.@@..@@.@@..@...@.@@@@.@@@..@@@@.@@@@@@@@..@@@.@@.@..@@@@.@@@.@..@@@@@@@@@@@..@@@.@...@@..@..@@@@.@@@@@.@@@@@@...@@.@.@.@@.@@
+@@.@@@.@@@@@@.@.@@@@@@@.@@@@@@@@@..@@.@..@@@@.@..@.@@.@@@.@.@.@.@@@@.@.@.@.@.@@.@.@.@@@@@@@@@@@..@@......@@@.@@.@@@@@@@@@@@..@..@..@@@@@@@@@
+@@@@.@@.@@@.@.@.@@@@..@@@@@@@@@..@..@.@@@.@@@@@..@@@@@.@@@@@..@@@@.@@.@...@@...@@.@..@..@@@...@..@...@@.@@@.@@.@..@@..@@@@@@@@@@@@.@@@@.@@@.

2025/go/go.mod

@@ -0,0 +1,16 @@
+module adventofcode2025
+
+go 1.23.2
+
+toolchain go1.23.5
+
+require (
+	github.com/stretchr/testify v1.11.1
+	golang.org/x/exp v0.0.0-20241009180824-f66d83c29e7c
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

2025/go/go.sum

@@ -0,0 +1,11 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+golang.org/x/exp v0.0.0-20241009180824-f66d83c29e7c h1:7dEasQXItcW1xKJ2+gg5VOiBnqWrJc+rq0DPKyvvdbY=
+golang.org/x/exp v0.0.0-20241009180824-f66d83c29e7c/go.mod h1:NQtJDoLvd6faHhE7m4T/1IY708gDefGGjR/iUW8yQQ8=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

2025/go/main.go

@@ -0,0 +1,158 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	//	"math/rand"
+	"os"
+	//	"strings"
+	//	"time"
+	"adventofcode2025/day01"
+	"adventofcode2025/day02"
+	"adventofcode2025/day03"
+	"adventofcode2025/day04"
+
+	"adventofcode2025/utils"
+)
+
+// Usage: go run main.go <NN>
+// assumes input is in day<NN>/input.txt
+func main() {
+	d := day()
+	fmt.Printf("Running day %02d\n", d)
+	start := time.Now()
+	switch d {
+	case 1:
+		fmt.Printf("part 1: %d\n", day01.Part1(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day01.Part2(utils.Readfile(d)))
+	case 2:
+		fmt.Printf("part 1: %d\n", day02.Part1(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day02.Part2(utils.Readfile(d)))
+	case 3:
+		fmt.Printf("part 1: %d\n", day03.Part1(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day03.Part2(utils.Readfile(d)))
+	case 4:
+		fmt.Printf("part 1: %d\n", day04.Part1(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day04.Part2(utils.Readfile(d)))
+		//	case 6:
+		//		fmt.Printf("part 1: %d\n", day06.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day06.Part2(utils.Readfile(d)))
+		//	case 7:
+		//		fmt.Printf("part 1: %d\n", day07.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day07.Part2(utils.Readfile(d)))
+		//	case 8:
+		//		fmt.Printf("part 1: %d\n", day08.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day08.Part2(utils.Readfile(d)))
+		//	case 9:
+		//		fmt.Printf("part 1: %d\n", day09.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day09.Part2(utils.Readfile(d)))
+		//	case 10:
+		//		fmt.Printf("part 1: %d\n", day10.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day10.Part2(utils.Readfile(d)))
+		//	case 11:
+		//		fmt.Printf("part 1: %d\n", day11.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day11.Part2(utils.Readfile(d)))
+		//	case 12:
+		//		fmt.Printf("part 1: %d\n", day12.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day12.Part2(utils.Readfile(d)))
+		//	case 13:
+		//		fmt.Printf("part 1: %d\n", day13.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day13.Part2(utils.Readfile(d)))
+		//	case 14:
+		//		fmt.Printf("part 1: %d\n", day14.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day14.Part2(utils.Readfile(d)))
+		//	case 15:
+		//		fmt.Printf("part 1: %d\n", day15.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day15.Part2(utils.Readfile(d)))
+		//	case 16:
+		//		fmt.Printf("part 1: %d\n", day16.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day16.Part2(utils.Readfile(d)))
+		//	case 17:
+		//		fmt.Printf("part 1: %s\n", day17.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day17.Part2(utils.Readfile(d)))
+		//	case 18:
+		//		fmt.Printf("part 1: %d\n", day18.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day18.Part2(utils.Readfile(d)))
+		//	case 19:
+		//		fmt.Printf("part 1: %d\n", day19.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day19.Part2(utils.Readfile(d)))
+		//	case 21:
+		//		fmt.Printf("part 1: %d\n", day21.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day21.Part2(utils.Readfile(d)))
+		//	case 22:
+		//		fmt.Printf("part 1: %d\n", day22.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day22.Part2(utils.Readfile(d)))
+		//	case 23:
+		//		fmt.Printf("part 1: %d\n", day23.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day23.Part2(utils.Readfile(d)))
+		//	case 24:
+		//		fmt.Printf("part 1: %d\n", day24.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day24.Part2(utils.Readfile(d)))
+		//	case 25:
+		//		fmt.Printf("part 1: %d\n", day25.Part1(utils.Readfile(d)))
+		//		fmt.Printf("part 2: %d\n", day25.Part2(utils.Readfile(d)))
+	default:
+		panic(fmt.Errorf("no such day: %d", d))
+	}
+	elapsed := time.Since(start)
+	fmt.Printf("Execution time: %s\n", elapsed)
+}
+
+// Reads day from os.Args.
+func day() int {
+	latest := 3
+	if len(os.Args) == 1 {
+		return latest
+	}
+
+	if os.Args[1] == "next" {
+		genNext(latest + 1)
+		os.Exit(0)
+	}
+	day := utils.MustAtoi(os.Args[1])
+	return day
+}
+
+func genNext(n int) {
+	os.Mkdir(fmt.Sprintf("day%02d", n), 0755)
+	f, err := os.Create(fmt.Sprintf("day%02d/day%02d.go", n, n))
+	utils.PanicOnErr(err)
+	defer f.Close()
+	f.WriteString(fmt.Sprintf(`package day%02d
+
+func Part1(input string) int {
+	return 0
+}
+
+func Part2(input string) int {
+	return 0
+}
+`, n))
+	fmt.Printf("wrote day%02d/day%02d.go\n", n, n)
+
+	f, err = os.Create(fmt.Sprintf("day%02d/day%02d_test.go", n, n))
+	utils.PanicOnErr(err)
+	defer f.Close()
+	f.WriteString(fmt.Sprintf(`package day%02d
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1("")
+	require.Equal(t, 0, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2("")
+	require.Equal(t, 0, r)
+}
+`, n))
+	fmt.Printf("wrote day%02d/day%02d_test.go\n", n, n)
+	utils.GenInputFile(n)
+
+}

2025/go/utils/dijkstra/graph.go

@@ -0,0 +1,241 @@
+package dijkstra
+
+import (
+	"math"
+	"sync"
+)
+
+type ItemGraph struct {
+	Nodes []*Node
+	Edges map[Node][]*Edge
+	lock  sync.RWMutex
+}
+
+// AddNode adds a node to the graph
+func (g *ItemGraph) AddNode(n *Node) {
+	g.lock.Lock()
+	g.Nodes = append(g.Nodes, n)
+	g.lock.Unlock()
+}
+
+// AddEdge adds an edge to the graph
+func (g *ItemGraph) AddEdge(n1, n2 *Node, weight int) {
+	g.lock.Lock()
+	if g.Edges == nil {
+		g.Edges = make(map[Node][]*Edge)
+	}
+	ed1 := Edge{
+		Node:   n2,
+		Weight: weight,
+	}
+
+	ed2 := Edge{
+		Node:   n1,
+		Weight: weight,
+	}
+	g.Edges[*n1] = append(g.Edges[*n1], &ed1)
+	g.Edges[*n2] = append(g.Edges[*n2], &ed2)
+	g.lock.Unlock()
+}
+
+// dijkstra implement
+func getShortestPath(startNode *Node, endNode *Node, g *ItemGraph) ([]Point, int) {
+	visited := make(map[Point]bool)
+	dist := make(map[Point]int)
+	prev := make(map[Point]Point)
+	//pq := make(PriorityQueue, 1)
+	//heap.Init(&pq)
+	q := NodeQueue{}
+	pq := q.NewQ()
+	start := Vertex{
+		Node:     startNode,
+		Distance: 0,
+	}
+	for _, nval := range g.Nodes {
+		dist[nval.Value] = math.MaxInt64
+	}
+	dist[startNode.Value] = start.Distance
+	pq.Enqueue(start)
+	//im := 0
+	for !pq.IsEmpty() {
+		v := pq.Dequeue()
+		if visited[v.Node.Value] {
+			continue
+		}
+		visited[v.Node.Value] = true
+		near := g.Edges[*v.Node]
+
+		for _, val := range near {
+			if !visited[val.Node.Value] {
+				if dist[v.Node.Value]+val.Weight < dist[val.Node.Value] {
+					store := Vertex{
+						Node:     val.Node,
+						Distance: dist[v.Node.Value] + val.Weight,
+					}
+					dist[val.Node.Value] = dist[v.Node.Value] + val.Weight
+					//prev[val.Node.Value] = fmt.Sprintf("->%s", v.Node.Value)
+					prev[val.Node.Value] = v.Node.Value
+					pq.Enqueue(store)
+				}
+				//visited[val.Node.value] = true
+			}
+		}
+	}
+	//	fmt.Println(dist)
+	//	fmt.Println(prev)
+	pathval := prev[endNode.Value]
+	var finalArr []Point
+	finalArr = append(finalArr, endNode.Value)
+	for pathval != startNode.Value {
+		finalArr = append(finalArr, pathval)
+		pathval = prev[pathval]
+	}
+	finalArr = append(finalArr, pathval)
+	//	fmt.Println(finalArr)
+	for i, j := 0, len(finalArr)-1; i < j; i, j = i+1, j-1 {
+		finalArr[i], finalArr[j] = finalArr[j], finalArr[i]
+	}
+	return finalArr, dist[endNode.Value]
+
+}
+
+func getAllShortestPaths(startNode *Node, endNode *Node, g *ItemGraph) ([][]Point, int) {
+	visited := make(map[Point]bool)
+	dist := make(map[Point]int)
+	prev := make(map[Point][]Point) // Store multiple predecessors for each node
+	q := NodeQueue{}
+	pq := q.NewQ()
+
+	start := Vertex{
+		Node:     startNode,
+		Distance: 0,
+	}
+
+	for _, n := range g.Nodes {
+		dist[n.Value] = math.MaxInt64
+	}
+	dist[startNode.Value] = start.Distance
+	pq.Enqueue(start)
+
+	// Perform Dijkstra's algorithm
+	for !pq.IsEmpty() {
+		v := pq.Dequeue()
+		if visited[v.Node.Value] {
+			continue
+		}
+		visited[v.Node.Value] = true
+		near := g.Edges[*v.Node]
+
+		for _, edge := range near {
+			alt := dist[v.Node.Value] + edge.Weight
+
+			// Case 1: Found a shorter path
+			if alt < dist[edge.Node.Value] {
+				dist[edge.Node.Value] = alt
+				prev[edge.Node.Value] = []Point{v.Node.Value} // Reset predecessors
+				pq.Enqueue(Vertex{
+					Node:     edge.Node,
+					Distance: alt,
+				})
+			}
+
+			// Case 2: Found an equally short path
+			if alt == dist[edge.Node.Value] {
+				// Add the current node as a valid predecessor if not already present
+				found := false
+				for _, p := range prev[edge.Node.Value] {
+					if p == v.Node.Value {
+						found = true
+						break
+					}
+				}
+				if !found {
+					prev[edge.Node.Value] = append(prev[edge.Node.Value], v.Node.Value)
+				}
+			}
+		}
+	}
+
+	// Iteratively reconstruct all paths
+	var paths [][]Point
+	stack := []struct {
+		node Point
+		path []Point
+	}{
+		{node: endNode.Value, path: []Point{}},
+	}
+
+	for len(stack) > 0 {
+		// Pop the top item from the stack
+		current := stack[len(stack)-1]
+		stack = stack[:len(stack)-1]
+
+		// Prepend the current node to the path
+		newPath := append([]Point{current.node}, current.path...)
+
+		// If we've reached the start node, save the path
+		if current.node.X == startNode.Value.X && current.node.Y == startNode.Value.Y {
+			paths = append(paths, newPath)
+			continue
+		}
+
+		// Push all predecessors onto the stack
+		for _, predecessor := range prev[current.node] {
+			if !Contains(newPath, predecessor) {
+				stack = append(stack, struct {
+					node Point
+					path []Point
+				}{
+					node: predecessor,
+					path: newPath,
+				})
+			}
+		}
+	}
+
+	return paths, dist[endNode.Value]
+}
+
+func Contains(slice []Point, value Point) bool {
+	for _, v := range slice {
+		if v == value { // Compare values
+			return true
+		}
+	}
+	return false
+}
+
+func CreateGraph(data InputGraph) *ItemGraph {
+	var g ItemGraph
+	nodes := make(map[Point]*Node)
+	for _, v := range data.Graph {
+		if _, found := nodes[v.Source]; !found {
+			nA := Node{v.Source}
+			nodes[v.Source] = &nA
+			g.AddNode(&nA)
+		}
+		if _, found := nodes[v.Destination]; !found {
+			nA := Node{v.Destination}
+			nodes[v.Destination] = &nA
+			g.AddNode(&nA)
+		}
+		g.AddEdge(nodes[v.Source], nodes[v.Destination], v.Weight)
+	}
+	return &g
+}
+
+func GetShortestPath(from, to Point, g *ItemGraph) ([]Point, int) {
+	nA := &Node{from}
+	nB := &Node{to}
+
+	path, distance := getShortestPath(nA, nB, g)
+	return path, distance
+}
+
+func GetAllShortestPaths(from, to Point, g *ItemGraph) ([][]Point, int) {
+	nA := &Node{from}
+	nB := &Node{to}
+
+	paths, distance := getAllShortestPaths(nA, nB, g)
+	return paths, distance
+}

2025/go/utils/dijkstra/object.go

@@ -0,0 +1,35 @@
+package dijkstra
+
+type Point struct {
+	X int
+	Y int
+	Label string
+}
+
+type Node struct {
+	Value Point
+}
+
+type Edge struct {
+	Node   *Node
+	Weight int
+}
+
+type Vertex struct {
+	Node     *Node
+	Distance int
+}
+
+type PriorityQueue []*Vertex
+
+type InputGraph struct {
+	Graph []InputData 
+	From  Point
+	To    Point
+}
+
+type InputData struct {
+	Source      Point 
+	Destination Point 
+	Weight      int
+}

2025/go/utils/dijkstra/queue.go

@@ -0,0 +1,65 @@
+package dijkstra
+
+import "sync"
+
+type NodeQueue struct {
+	Items []Vertex
+	lock  sync.RWMutex
+}
+
+// Enqueue adds an Node to the end of the queue
+func (s *NodeQueue) Enqueue(t Vertex) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	if len(s.Items) == 0 {
+		s.Items = append(s.Items, t)
+		return
+	}
+	var insertFlag bool
+	for k, v := range s.Items {
+		// add vertex distance less than travers's vertex distance
+		if t.Distance < v.Distance {
+			s.Items = append(s.Items[:k+1], s.Items[k:]...)
+			s.Items[k] = t
+			insertFlag = true
+		}
+		if insertFlag {
+			break
+		}
+	}
+	if !insertFlag {
+		s.Items = append(s.Items, t)
+	}
+}
+
+// Dequeue removes an Node from the start of the queue
+func (s *NodeQueue) Dequeue() *Vertex {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+	item := s.Items[0]
+	s.Items = s.Items[1:len(s.Items)]
+	return &item
+}
+
+//NewQ Creates New Queue
+func (s *NodeQueue) NewQ() *NodeQueue {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+	s.Items = []Vertex{}
+	return s
+}
+
+// IsEmpty returns true if the queue is empty
+func (s *NodeQueue) IsEmpty() bool {
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+	return len(s.Items) == 0
+}
+
+// Size returns the number of Nodes in the queue
+func (s *NodeQueue) Size() int {
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+	return len(s.Items)
+}

2025/go/utils/grid2d/grid2d.go

@@ -0,0 +1,77 @@
+package grid2d
+
+import (
+	"strings"
+
+	"adventofcode2025/utils"
+)
+
+type Grid[T any] struct {
+	sizeX, sizeY int
+	matrix       [][]T
+	empty        T
+}
+
+func NewGrid[T any](sizeX, sizeY int, empty T) *Grid[T] {
+	matrix := make([][]T, sizeY)
+	rows := make([]T, sizeX*sizeY)
+	for i := 0; i < sizeX*sizeY; i++ {
+		rows[i] = empty
+	}
+
+	j := 0
+	for i := 0; i < sizeY; i++ {
+		matrix[i] = rows[j : j+sizeX : j+sizeX]
+		j += sizeX
+	}
+	return &Grid[T]{
+		sizeX:  sizeX,
+		sizeY:  sizeY,
+		matrix: matrix,
+		empty:  empty,
+	}
+}
+
+func (g *Grid[T]) SizeX() int {
+	return g.sizeX
+}
+
+func (g *Grid[T]) SizeY() int {
+	return g.sizeY
+}
+func (g *Grid[T]) Matrix() [][]T {
+	return g.matrix
+} 
+
+func (g *Grid[T]) Get(x, y int) T {
+	if x < 0 || x >= g.sizeX {
+		return g.empty
+	}
+	if y < 0 || y >= g.sizeY {
+		return g.empty
+	}
+	return g.matrix[y][x]
+}
+
+func (g *Grid[T]) Set(x, y int, v T) {
+	if x < 0 || x >= g.sizeX {
+		panic("invalid x")
+	}
+	if y < 0 || y >= g.sizeY {
+		panic("invalid y")
+	}
+	g.matrix[y][x] = v
+}
+
+func (g *Grid[T]) StringWithFormatter(formatter func(T, int, int) string) string {
+	var r strings.Builder
+	for j := 0; j < g.sizeY; j++ {
+		for i := 0; i < g.sizeX; i++ {
+			_, err := r.WriteString(formatter(g.matrix[j][i], i, j))
+			utils.PanicOnErr(err)
+		}
+		_, err := r.WriteRune('\n')
+		utils.PanicOnErr(err)
+	}
+	return r.String()
+}

2025/go/utils/inputFile.go

@@ -0,0 +1,63 @@
+package utils
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+)
+
+func GenInputFile(day int) string {
+	var d string
+	if day < 10 {
+		d = fmt.Sprintf("0%d", day)
+	} else {
+		d = fmt.Sprintf("%d", day)
+	}
+
+	pwd, _ := os.Getwd()
+	path := fmt.Sprintf("%s/day%s/input.txt", pwd, d)
+	fi, _ := os.Stat(path)
+	if fi != nil {
+		return path
+	}
+
+	fmt.Printf("Creating new input file %v...", path)
+	f, err := os.Create(path)
+	if err != nil {
+		fmt.Println(err)
+	} else {
+		defer f.Close()
+		data := readHttp(2025, day)
+		_, err := f.WriteString(data)
+		if err != nil {
+			fmt.Println(err)
+		}
+	}
+	return path
+}
+
+func readHttp(year, day int) string {
+	fmt.Println("Fetching data into file...")
+
+	url := fmt.Sprintf("https://adventofcode.com/%d/day/%d/input", year, day)
+	session := os.Getenv("sessionAoC")
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		panic(err)
+	}
+
+	req.AddCookie(&http.Cookie{Name: "session", Value: session})
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		panic(err)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		panic(err)
+	}
+	return string(body)
+}
+

2025/go/utils/inputs/inputs.go

@@ -0,0 +1,56 @@
+package inputs
+
+import (
+	"strings"
+
+	"adventofcode2025/utils"
+	"adventofcode2025/utils/grid2d"
+	sparsegrid "adventofcode2025/utils/sparseGrid"
+)
+
+func ToInts(input string, sep string) []int {
+	var r []int
+	for _, line := range strings.Split(input, sep) {
+		if line != "" {
+			r = append(r, utils.MustAtoi(line))
+		}
+	}
+	return r
+}
+
+func ToGrid2D[T any](input, rowSep, colSep string, empty T, conv func(string) T) *grid2d.Grid[T] {
+
+	var width int
+	
+	lines := strings.Split(input, rowSep)
+	
+	if colSep == "" {
+        // If no colSep, width is the length of each line
+        width = len(lines[0])
+    } else {
+        // Use colSep to determine the width of the grid
+        width = len(strings.Split(lines[0], colSep))
+    }
+
+	grid := grid2d.NewGrid(width, len(lines), empty)
+	for y, line := range lines {
+		for x, v := range strings.Split(line, colSep) {
+			grid.Set(x, y, conv(v))
+		}
+	}
+
+	return grid
+}
+
+func ToSparseGrid[T comparable](input, rowSep, colSep string, empty T, conv func(string) T) *sparsegrid.SparseGrid[T] {
+	lines := strings.Split(input, rowSep)
+
+	grid := sparsegrid.NewGrid(empty)
+	for y, line := range lines {
+		for x, v := range strings.Split(line, colSep) {
+			grid.Set(x, y, conv(v))
+		}
+	}
+
+	return grid
+}

2025/go/utils/memo/memo.go

@@ -0,0 +1,47 @@
+package memo
+
+import "sync"
+
+type Func func(key interface{}) interface{}
+
+type result struct {
+	value interface{}
+}
+
+type Memo struct {
+	f     Func
+	cache map[interface{}]result
+	mu    sync.RWMutex // Allows concurrent reads.
+}
+
+func New(f Func) *Memo {
+	return &Memo{
+		f:     f,
+		cache: make(map[interface{}]result),
+	}
+}
+
+func (memo *Memo) Get(key interface{}) interface{} {
+	// First, try to read the cache using a read lock.
+	memo.mu.RLock()
+	res, ok := memo.cache[key]
+	memo.mu.RUnlock()
+	if ok {
+		return res.value
+	}
+
+	// Compute the result without holding the lock.
+	computed := memo.f(key)
+
+	// Now acquire a write lock to update the cache.
+	memo.mu.Lock()
+	// Double-check: another goroutine may have stored the result in the meantime.
+	res, ok = memo.cache[key]
+	if !ok {
+		res.value = computed
+		memo.cache[key] = res
+	}
+	memo.mu.Unlock()
+
+	return res.value
+}

2025/go/utils/ringbuffer/ringbuffer.go

@@ -0,0 +1,56 @@
+package ringbuffer
+
+import (
+	"sync"
+)
+
+type RingBuffer[T any] struct {
+	buffer []T
+	size   int
+	mu     sync.Mutex
+	write  int
+	count  int
+}
+
+// NewRingBuffer creates a new ring buffer with a fixed size.
+func NewRingBuffer[T any](size int) *RingBuffer[T] {
+	return &RingBuffer[T]{
+		buffer: make([]T, size),
+		size:   size,
+	}
+}
+
+// Add inserts a new element into the buffer, overwriting the oldest if full.
+func (rb *RingBuffer[T]) Add(value T) {
+	rb.mu.Lock()
+	defer rb.mu.Unlock()
+
+	rb.buffer[rb.write] = value
+	rb.write = (rb.write + 1) % rb.size
+
+	if rb.count < rb.size {
+		rb.count++
+	}
+}
+
+// Get returns the contents of the buffer in FIFO order.
+func (rb *RingBuffer[T]) Get() []T {
+	rb.mu.Lock()
+	defer rb.mu.Unlock()
+
+	result := make([]T, 0, rb.count)
+
+	for i := 0; i < rb.count; i++ {
+		index := (rb.write + rb.size - rb.count + i) % rb.size
+		result = append(result, rb.buffer[index])
+	}
+
+	return result
+}
+
+// Len returns the current number of elements in the buffer.
+func (rb *RingBuffer[T]) Len() int {
+	rb.mu.Lock()
+	defer rb.mu.Unlock()
+	return rb.count
+}

2025/go/utils/sparseGrid/sparseGrid.go

@@ -0,0 +1,81 @@
+package sparsegrid
+
+import (
+	"fmt"
+	"strings"
+
+	"adventofcode2025/utils"
+)
+
+type SparseGrid[T comparable] struct {
+	minX, maxX, minY, maxY int
+	data                   map[string]T
+	empty                  T
+}
+
+func NewGrid[T comparable](empty T) *SparseGrid[T] {
+	return &SparseGrid[T]{
+		minX:  utils.MaxInt,
+		maxX:  utils.MinInt,
+		minY:  utils.MaxInt,
+		maxY:  utils.MinInt,
+		data:  map[string]T{},
+		empty: empty,
+	}
+}
+
+func (g *SparseGrid[T]) SizeX() (int, int) {
+	return g.minX, g.maxX
+}
+
+func (g *SparseGrid[T]) SizeY() (int, int) {
+	return g.minY, g.maxY
+}
+
+func (g *SparseGrid[T]) Visited() int {
+	return len(g.data)
+}
+
+func (g *SparseGrid[T]) Get(x, y int) T {
+	k := key(x, y)
+	v, ok := g.data[k]
+	if !ok {
+		return g.empty
+	}
+	return v
+}
+
+func (g *SparseGrid[T]) Set(x, y int, v T) {
+	k := key(x, y)
+	current, ok := g.data[k]
+	if ok && v == current {
+		return
+	} else if !ok && v == g.empty {
+		return
+	} else if v == g.empty {
+		delete(g.data, k)
+	} else {
+		g.data[k] = v
+		g.minX = utils.Min(g.minX, x)
+		g.maxX = utils.Max(g.maxX, x)
+		g.minY = utils.Min(g.minY, y)
+		g.maxY = utils.Max(g.maxY, y)
+	}
+}
+
+func (g *SparseGrid[T]) StringWithFormatter(formatter func(T, int, int) string) string {
+	var r strings.Builder
+	for j := g.minY; j <= g.maxY; j++ {
+		for i := g.minX; i <= g.maxX; i++ {
+			_, err := r.WriteString(formatter(g.Get(i, j), i, j))
+			utils.PanicOnErr(err)
+		}
+		_, err := r.WriteRune('\n')
+		utils.PanicOnErr(err)
+	}
+	return r.String()
+}
+
+func key(x, y int) string {
+	return fmt.Sprintf("%d:%d", x, y)
+}

2025/go/utils/utils.go

@@ -0,0 +1,222 @@
+package utils
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"golang.org/x/exp/constraints"
+)
+
+func PanicOnErr(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+const MaxInt = int(^uint(0) >> 1)
+const MinInt = ^MaxInt
+
+func Max[T constraints.Ordered](a, b T) T {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func Min[T constraints.Ordered](a, b T) T {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func SliceMinMax[T constraints.Ordered](slice []T) (*T, *T) {
+	if len(slice) == 0 {
+		return nil, nil
+	}
+	min := &slice[0]
+	max := &slice[0]
+	for i, v := range slice {
+		if v < *min {
+			min = &slice[i]
+		}
+		if v > *max {
+			max = &slice[i]
+		}
+	}
+	return min, max
+}
+
+func MustAtoi(s string) int {
+	v, err := strconv.Atoi(s)
+	PanicOnErr(err)
+	return v
+}
+
+// Returns key from map[T]int which has the max value
+func MapFindMax(m interface{}) interface{} {
+	var maxK interface{} = nil
+	var maxV = MinInt
+	iter := reflect.ValueOf(m).MapRange()
+	for iter.Next() {
+		k := iter.Key()
+		v := int(iter.Value().Int())
+		if v > maxV {
+			maxV = v
+			maxK = k.Interface()
+		}
+	}
+	return maxK
+}
+
+// Returns key from map[T]int which has the min value
+func MapFindMin(m interface{}) interface{} {
+	var minK interface{} = nil
+	var minV = MaxInt
+	iter := reflect.ValueOf(m).MapRange()
+	for iter.Next() {
+		k := iter.Key()
+		v := int(iter.Value().Int())
+		if v < minV {
+			minV = v
+			minK = k.Interface()
+		}
+	}
+	return minK
+}
+
+func Readfile(day int) string {
+	filename := fmt.Sprintf("day%02d/input.txt", day)
+	file, err := os.Open(filename)
+	PanicOnErr(err)
+	defer file.Close()
+
+	reader := bufio.NewReader(file)
+	contents, err := io.ReadAll(reader)
+	PanicOnErr(err)
+
+	return strings.TrimSuffix(string(contents), "\n")
+}
+
+func ReadfileAsSlice(day int) []string {
+	filename := fmt.Sprintf("day%02d/input.txt", day)
+	file, err := os.Open(filename)
+	PanicOnErr(err)
+	defer file.Close()
+
+	arr := make([]string, 0)
+	sc := bufio.NewScanner(file)
+	for sc.Scan() {
+		arr = append(arr, sc.Text())
+	}
+
+	return arr
+}
+
+func ParseToStruct(re *regexp.Regexp, input string, target interface{}) bool {
+	m := re.FindStringSubmatch(input)
+	if m == nil {
+		return false
+	}
+
+	var useOffset bool
+
+	for i, name := range re.SubexpNames() {
+		if i == 0 {
+			continue
+		}
+		var field reflect.Value
+		if name == "" {
+			// use offset
+			if i == 1 {
+				useOffset = true
+			} else if !useOffset {
+				panic("can't mix named and unnamed subexpressions")
+			}
+			field = reflect.ValueOf(target).Elem().Field(i - 1)
+		} else {
+			// use name
+			if i == 1 {
+				useOffset = false
+			} else if useOffset {
+				panic("can't mix named and unnamed subexpressions")
+			}
+			field = reflect.ValueOf(target).Elem().FieldByName(name)
+		}
+		if field.Kind() == reflect.String {
+			field.SetString(m[i])
+		} else if field.Kind() == reflect.Int {
+			v, err := strconv.Atoi(m[i])
+			PanicOnErr(err)
+			field.SetInt(int64(v))
+		} else if field.Kind() == reflect.Uint8 {
+			if len(m[i]) != 1 {
+				panic(fmt.Sprintf("expecting 1 char, got: %s", m[i]))
+			}
+			field.SetUint(uint64(m[i][0]))
+		} else {
+			panic(fmt.Sprintf("unknown kind: %s", field.Kind()))
+		}
+	}
+	return true
+}
+
+func MustParseToStruct(re *regexp.Regexp, input string, target interface{}) {
+	if !ParseToStruct(re, input, target) {
+		panic(fmt.Errorf("failed to parse: %s", input))
+	}
+}
+
+func CharToLower(c byte) byte {
+	return strings.ToLower(string(c))[0]
+}
+
+func CharToUpper(c byte) byte {
+	return strings.ToUpper(string(c))[0]
+}
+
+func Contains(haystack []string, needle string) bool {
+	for _, s := range haystack {
+		if s == needle {
+			return true
+		}
+	}
+	return false
+}
+
+func Abs[T constraints.Signed](x T) T {
+	if x < 0 {
+		return -x
+	}
+	return x
+}
+
+func Gcd(x, y int) int {
+	if x <= 0 || y <= 0 {
+		panic(fmt.Errorf("invalid input: %d, %d", x, y))
+	}
+	if x == y {
+		return x
+	}
+	if x > y {
+		return Gcd(x-y, y)
+	} else {
+		return Gcd(x, y-x)
+	}
+}
+
+func Sign[T constraints.Signed](x T) int {
+	if x < 0 {
+		return -1
+	} else if x > 0 {
+		return 1
+	} else {
+		return 0
+	}
+}