day9,10,11

2023/go/day09/day09.go

@@ -0,0 +1,71 @@
+package day09
+
+import (
+	_ "fmt"
+	"strings"
+	
+	"adventofcode2023/utils/inputs"
+
+)
+
+func Part1(input string) int {
+	ins := parseInput(input)
+	ans := 0 
+	for _, in := range ins {
+		ans += f1(in)
+	} 
+	return ans
+}
+
+func Part2(input string) int {
+	ins := parseInput(input)
+	ans := 0 
+	for _, in := range ins {
+		reverse(in)
+		ans += f1(in)
+	} 
+	return ans}
+
+func f1(in []int) int {
+	out := []int{}
+	for i:=0;i<len(in)-1;i++{
+		out = append(out, in[i+1] - in[i])
+	}
+	if allZero(out) {
+		return in[len(in) -1]
+	} else {
+		return in[len(in) -1] + f1(out)
+	}
+}
+
+func reverse(nums []int) {
+    for i, j := 0, len(nums)-1; i < j; i, j = i+1, j-1 {
+        nums[i], nums[j] = nums[j], nums[i]
+    }
+}
+
+func allZero(in []int) bool {
+	for _, v := range in {
+		if v != 0 {
+			return false
+		}
+	}
+	return true
+}
+
+func diff(in []int) []int {
+	out := []int{}
+	for i:=0;i<len(in)-1;i++{
+		out = append(out, in[i+1] - in[i])
+	}
+	return out
+}
+
+func parseInput(input string) ([][]int) {
+	lines := strings.Split(input, "\n")
+	out := [][]int{}
+	for _, line := range lines {
+		out = append(out, inputs.ToInts(line, " "))
+	}
+ 	return out
+}