diff --git a/internal/2025/DayFive/code.go b/internal/2025/DayFive/code.go new file mode 100644 index 0000000..293d3f7 --- /dev/null +++ b/internal/2025/DayFive/code.go @@ -0,0 +1,79 @@ +package dayfive + +import ( + "os" + "slices" + "sort" + "strconv" + "strings" + + "advent-of-code/internal/registry" +) + +type freshRange struct { + start int + end int +} + +func init() { + registry.Register("2025D5", ParseInput, PartOne, PartTwo) +} + +func ParseInput(filepath string) []string { + content, _ := os.ReadFile(filepath) + return strings.Split(string(content), "\n") +} + +func PartOne(input []string) int { + var freshRanges []freshRange + var ingredientIDs []int + separatorFound := false + + for _, line := range input { + if line == "" { + separatorFound = true + continue + } + + if !separatorFound { + startStr, endStr, _ := strings.Cut(line, "-") + start, _ := strconv.Atoi(startStr) + end, _ := strconv.Atoi(endStr) + freshRanges = append(freshRanges, freshRange{start: start, end: end}) + } else { + id, _ := strconv.Atoi(line) + ingredientIDs = append(ingredientIDs, id) + } + } + + slices.SortFunc(freshRanges, func(a, b freshRange) int { + switch { + case a.start < b.start: + return -1 + case a.start > b.start: + return 1 + default: + return 0 + } + }) + + freshCount := 0 + for _, id := range ingredientIDs { + idx := sort.Search(len(freshRanges), func(idx int) bool { + return freshRanges[idx].start > id + }) + + for i := idx - 1; i >= 0 && freshRanges[i].start <= id; i-- { + if id <= freshRanges[i].end { + freshCount++ + break + } + } + } + + return freshCount +} + +func PartTwo(input []string) int { + return 0 +}