2024 day1

2024/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",
+            "args": ["16"],
+            "program": "${fileDirname}"
+        }
+    ]
+}

2024/go/day01/day01.go

@@ -0,0 +1,54 @@
+package day01
+
+import (
+	"adventofcode2024/utils"
+	"sort"
+	"strings"
+)
+
+func Part1(input string) int {
+	var list1, list2 []int
+
+	num := 0
+	lines := strings.Split(input, "\n")
+	for _, line := range lines {
+		fields := strings.Fields(line)
+		// Convert the fields to integers
+		val1 := utils.MustAtoi(fields[0])
+		val2 := utils.MustAtoi(fields[1])
+
+		// Append to the respective slices
+		list1 = append(list1, val1)
+		list2 = append(list2, val2)
+	}
+	sort.Ints(list1)
+	sort.Ints(list2)
+	for i := 0; i < len(list1); i++ {
+		num += utils.Abs(list1[i] - list2[i])
+	}
+	return num
+
+}
+
+func Part2(input string) int {
+	var list1 []int
+	list2 := make(map[int]int)
+
+
+	num := 0
+	lines := strings.Split(input, "\n")
+	for _, line := range lines {
+		fields := strings.Fields(line)
+		// Convert the fields to integers
+		val1 := utils.MustAtoi(fields[0])
+		val2 := utils.MustAtoi(fields[1])
+
+		// Append to the respective slices
+		list1 = append(list1, val1)
+		list2[val2]++
+	}
+	for i := 0; i < len(list1); i++ {
+		num += list1[i] * list2[list1[i]]
+	}
+	return num
+}

2024/go/day01/day01_test.go

@@ -0,0 +1,17 @@
+package day01
+
+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/go.mod

@@ -0,0 +1,5 @@
+module adventofcode2024
+
+go 1.19
+
+require golang.org/x/exp v0.0.0-20221208152030-732eee02a75a

2024/go/go.sum

@@ -0,0 +1,2 @@
+golang.org/x/exp v0.0.0-20221208152030-732eee02a75a h1:4iLhBPcpqFmylhnkbY3W0ONLUYYkDAW9xMFLfxgsvCw=
+golang.org/x/exp v0.0.0-20221208152030-732eee02a75a/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=

2024/go/main.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"fmt"
+//	"math/rand"
+	"os"
+//	"strings"
+//	"time"
+	"adventofcode2024/utils"
+	"adventofcode2024/day01"
+)
+// 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)
+
+	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)))
+	default:
+		panic(fmt.Errorf("no such day: %d", d))
+	}
+}
+
+// Reads day from os.Args.
+func day() int {
+	latest := 1
+	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)
+
+}

2024/go/utils/grid2d/grid2d.go

@@ -0,0 +1,77 @@
+package grid2d
+
+import (
+	"strings"
+
+	"adventofcode2024/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()
+}

2024/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(2024, 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)
+}
+

2024/go/utils/inputs/inputs.go

@@ -0,0 +1,45 @@
+package inputs
+
+import (
+	"strings"
+
+	"adventofcode2024/utils"
+	"adventofcode2024/utils/grid2d"
+	sparsegrid "adventofcode2024/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] {
+	lines := strings.Split(input, rowSep)
+
+	grid := grid2d.NewGrid(len(lines[0]), 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
+}

2024/go/utils/sparseGrid/sparseGrid.go

@@ -0,0 +1,81 @@
+package sparsegrid
+
+import (
+	"fmt"
+	"strings"
+
+	"adventofcode2024/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)
+}

2024/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
+	}
+}