package daytwo import ( "os" "strconv" "strings" "advent-of-code/internal/registry" ) func init() { registry.Register("2025D2", ParseInput, PartOne, PartTwo) } func ParseInput(filepath string) []string { content, _ := os.ReadFile(filepath) return strings.Split(strings.TrimSpace(string(content)), "\n") } func PartOne(input []string) int { sum := 0 for _, line := range input { for newRange := range strings.SplitSeq(line, ",") { parts := strings.Split(newRange, "-") start, _ := strconv.Atoi(parts[0]) end, _ := strconv.Atoi(parts[1]) for id := start; id <= end; id++ { sID := strconv.Itoa(id) if len(sID)%2 == 0 { half := len(sID) / 2 if sID[:half] == sID[half:] { sum += id } } } } } return sum } func PartTwo(input []string) int { sum := 0 for _, line := range input { for newRange := range strings.SplitSeq(line, ",") { parts := strings.Split(newRange, "-") start, _ := strconv.Atoi(parts[0]) end, _ := strconv.Atoi(parts[1]) for id := start; id <= end; id++ { sID := strconv.Itoa(id) found := false for patternLength := 1; patternLength <= len(sID)/2 && !found; patternLength++ { if len(sID)%patternLength == 0 { matches := true for idx := 0; idx < len(sID)-patternLength; idx++ { if sID[idx] != sID[idx+patternLength] { matches = false break } } if matches { sum += id found = true } } } } } } return sum }