AOC2022/day13/day13.go

package main

import (
	"AOC2022/helper"
	"fmt"
	"strconv"
)

func main() {
	//args := os.Args[1:]
	lines := helper.ReadTextFile("day13/testinput")
	result := 0
	index := 1
	for i := 18; i < len(lines); i += 3 {
		fmt.Println(i)
		if comparePair(lines[i], lines[i+1]) {
			result += index
		}
		index++
	}
	fmt.Println(result)

}

func comparePair(left string, right string) bool {
	lefIndex := 0
	rightIndex := 0
	currentElemLeft := 0
	currentElemRight := 0
	for lefIndex < len(left)-1 {
		lefIndex = getNextElement(left, lefIndex)
		if left[lefIndex] == ']' {
			lefIndex = getNextElement(left, lefIndex+1)
			rightIndex = getEndofCurrentArray(right, rightIndex)
			rightIndex = getNextElement(right, rightIndex+1)
		} else {
			rightIndex = getNextElement(right, rightIndex)
			if rightIndex == -1 {
				return false
			}
			if lefIndex == -1 {
				return true
			}
			currentElemLeft, lefIndex = readElement(left, lefIndex)
			currentElemRight, rightIndex = readElement(right, rightIndex)
			fmt.Println(currentElemLeft)
			fmt.Println(currentElemRight)
			fmt.Println()
			if currentElemLeft > currentElemRight {
				return false
			}
			if currentElemLeft < currentElemRight {
				return true
			}
		}
	}
	return true
}

// 0 Element
//-1 End Packet
//-2 Start Array
//-3 End Array
func getNextElement(packet string, currentIndex int) (int, int) {
	index := currentIndex
	for index < len(packet) {
		switch packet[index] {
		case ',':
			index++
			break
		case '[':
			return index, -2
			break
		case ']':
			if index < len(packet)-1 {
				return index, -3
			} else {
				index++
			}
			break
		default:
			return index, 0
		}
	}
	return index, -1
}

func getEndofCurrentArray(packet string, currentIndex int) int {
	index := currentIndex
	for index < len(packet) {
		if packet[index] == ']' {
			return index
		}
		index++
	}
	return -1
}

func readElement(packet string, currentIndex int) (element, newIndex int) {
	index := currentIndex
	newIndex = 0
	for newIndex == 0 {
		switch packet[index] {
		case ',':
			newIndex = index
			break
		case ']':
			newIndex = index
			break
		default:
			index++
		}
	}
	return helper.RemoveError(strconv.Atoi(packet[currentIndex:newIndex])), newIndex
}