2025-day02

Author: liamgallear

2025/day02/.bench

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+{"Lines":[{"Name":"Part 1","N":43,"NsPerOp":25847627,"AllocedBytesPerOp":0,"AllocsPerOp":0,"MBPerS":0,"Measured":1,"Ord":0},{"Name":"Part 2","N":3,"NsPerOp":452777889,"AllocedBytesPerOp":0,"AllocsPerOp":0,"MBPerS":0,"Measured":1,"Ord":0}],"Measured":1}

2025/day02/README.md

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+<!-- You can add some comments here if you want to :D -->

2025/day02/main.go

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+package main
+
+import (
+	_ "embed"
+	"os"
+)
+
+//go:embed input.txt
+var input string
+
+//go:embed input_test.txt
+var inputTest string
+
+func main() {
+	// Check argv if we use test input or not
+	if len(os.Args) > 1 && os.Args[1] == "test" {
+		input = inputTest
+	}
+
+	answer := doPartOne(input)
+	println(answer)
+
+	answer = doPartTwo(input)
+	println(answer)
+}

2025/day02/main_test.go

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+package main
+
+import "testing"
+
+func BenchmarkPartOne(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		doPartOne(input)
+	}
+}
+
+func BenchmarkPartTwo(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		doPartTwo(input)
+	}
+}

2025/day02/part1.go

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+package main
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+func doPartOne(input string) int {
+	lines := strings.Split(strings.Split(strings.TrimSpace(input), "\n")[0], ",")
+	ans := 0
+	for _, line := range lines {
+		var id1, id2 int
+		fmt.Sscanf(line, "%d-%d", &id1, &id2)
+		for id := id1; id <= id2; id++ {
+			idstring := strconv.Itoa(id)
+			if len(idstring)%2 != 0 {
+				continue
+			}
+			mid := len(idstring) / 2
+			if idstring[:mid] == idstring[mid:] {
+				ans += id
+			}
+		}
+	}
+	return ans
+}

2025/day02/part2.go

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+package main
+
+import (
+	"aocli/utils"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+func doPartTwo(input string) int {
+	lines := strings.Split(strings.Split(strings.TrimSpace(input), "\n")[0], ",")
+	ans := 0
+	for _, line := range lines {
+		var id1, id2 int
+		fmt.Sscanf(line, "%d-%d", &id1, &id2)
+	nextid:
+		for id := id1; id <= id2; id++ {
+			idstring := strconv.Itoa(id)
+			mid := len(idstring) / 2
+			for i := 1; i <= mid; i++ {
+				if len(idstring)%i != 0 {
+					continue
+				}
+				chunks := utils.ChunkSlice([]rune(idstring), i)
+				match := true
+				for i := 1; i < len(chunks); i++ {
+					if string(chunks[i]) != string(chunks[0]) {
+						match = false
+						break
+					}
+				}
+				if match {
+					ans += id
+					continue nextid
+				}
+			}
+		}
+	}
+	return ans
+}