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

2025/go/main.go

@@ -9,6 +9,10 @@ import (
 	//	"strings"
 	//	"time"
 	"adventofcode2025/day01"
+	"adventofcode2025/day02"
+	"adventofcode2025/day03"
+	"adventofcode2025/day04"
+
 	"adventofcode2025/utils"
 )
 
@@ -22,15 +26,15 @@ 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:
+	case 3:
-//		fmt.Printf("part 1: %d\n", day03.Part1(utils.Readfile(d)))
+		fmt.Printf("part 1: %d\n", day03.Part1(utils.Readfile(d)))
-//		fmt.Printf("part 2: %d\n", day03.Part2(utils.Readfile(d)))
+		fmt.Printf("part 2: %d\n", day03.Part2(utils.Readfile(d)))
-//	case 4:
+	case 4:
-//		fmt.Printf("part 1: %d\n", day04.Part1(utils.Readfile(d)))
+		fmt.Printf("part 1: %d\n", day04.Part1(utils.Readfile(d)))
-//		fmt.Printf("part 2: %d\n", day04.Part2(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)))
@@ -97,7 +101,7 @@ func main() {
 
 // Reads day from os.Args.
 func day() int {
-	latest := 0
+	latest := 3
 	if len(os.Args) == 1 {
 		return latest
 	}