day02

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
+						break
+					}
+
+				}
+				if found {
+					count += utils.MustAtoi(s)
+					break
+				}
+			}
+		}
+	}
+	return count
+}

2025/go/day02/day02_test.go

@@ -0,0 +1,17 @@
+package day02
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1("446443-446449")
+	require.Equal(t, 446446, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2("222220-222224")
+	require.Equal(t, 222222, r)
+}

2025/go/day02/input.txt

@@ -0,0 +1 @@
+69810572-69955342,3434061167-3434167492,76756725-76781020,49-147,296131-386620,910523-946587,34308309-34358652,64542-127485,640436-659023,25-45,35313993-35393518,753722181-753795479,1544-9792,256-647,444628-483065,5863911-6054673,6969623908-6969778569,658-1220,12631-63767,670238-830345,1-18,214165106-214245544,3309229-3355697

2025/go/main.go

@@ -9,6 +9,7 @@ import (
 	//	"strings"
 	//	"time"
 	"adventofcode2025/day01"
+	"adventofcode2025/day02"
 	"adventofcode2025/utils"
 )
 
@@ -22,9 +23,9 @@ func main() {
 	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:
+	case 2:
-//		fmt.Printf("part 1: %d\n", day02.Part1(utils.Readfile(d)))
+		fmt.Printf("part 1: %d\n", day02.Part1(utils.Readfile(d)))
-//		fmt.Printf("part 2: %d\n", day02.Part2(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)))
@@ -97,7 +98,7 @@ func main() {
 
 // Reads day from os.Args.
 func day() int {
-	latest := 0
+	latest := 1
 	if len(os.Args) == 1 {
 		return latest
 	}