AOC2022/day6/day6.go

package main

import (
	"AOC2022/helper"
	"fmt"
)

func main() {
	//args := os.Args[1:]
	lines := helper.ReadTextFile("day6/input")
	defer helper.MeasureTime("Task One")()
	for _, line := range lines {
		fmt.Println(getIndexOfFirstNUniqueCharacters(4, line))
		fmt.Println(getIndexOfFirstNUniqueCharacters(14, line))
	}
}

func getIndexOfFirstNUniqueCharacters(n int, line string) int {
	i := 0
	fit := false
	for !fit && i < len(line) {
		firstRepeat := getFirstNRepeat(n, line[i:])
		if firstRepeat == -1 {
			fit = true
		} else {
			i += firstRepeat
		}

	}
	return i + n + 1
}

func getFirstNRepeat(n int, line string) int {
	usedCharacters := map[string]int{}
	for i, character := range line {
		if usedCharacters[string(character)] != 0 {
			return usedCharacters[string(character)]
		}
		usedCharacters[string(character)] = i
		if len(usedCharacters) == n {
			return -1
		}

	}
	return -1
}