Files
advent-of-code/internal/2025/DayTwo/code.go

58 lines
1.1 KiB
Go

package daytwo
import (
"os"
"strconv"
"strings"
"advent-of-code/internal/registry"
)
func init() {
registry.Register("2025D2", ParseInput, PartOne, PartTwo)
}
func isInvalid(id int, exactTwo bool) bool {
sID := strconv.Itoa(id)
if exactTwo {
half := len(sID) / 2
return sID[:half] == sID[half:]
}
for patternLength := 1; patternLength <= len(sID)/2; patternLength++ {
repetitions := len(sID) / patternLength
if repetitions < 2 || len(sID)%patternLength != 0 {
continue
}
if strings.Repeat(sID[:patternLength], repetitions) == sID {
return true
}
}
return false
}
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++ {
if isInvalid(id, true) {
sum += id
}
}
}
}
return sum
}
func PartTwo(input []string) int {
return 0
}