AOC2022/day22/day22.go

package main

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

func main() {
	//args := os.Args[1:]
	lines := helper.ReadTextFile("day22/input")
	commandsLine := lines[len(lines)-1]
	commandsLine = strings.ReplaceAll(commandsLine, "R", "R,")
	commandsLine = strings.ReplaceAll(commandsLine, "L", "L,")
	commands := strings.Split(commandsLine, ",")
	fmt.Println(commands)
	part1(lines, commands)
	part2(lines, commands)

}

func part2(lines []string, commands []string) {
	fields := [][][]rune{}
	fields, cutFields := part2Parser(lines, fields, 50)
	currentPosition := [4]int{0, 0, 0, 0}
	for i, c := range cutFields[0][0] {
		if c == '.' {
			currentPosition[1] = i
			break
		}
	}
	fmt.Println(currentPosition)
	for i, command := range commands {
		fmt.Println(command)
		currentPosition = runCommand(cutFields, command, currentPosition, true)
		fmt.Printf("%v: %v \n", i+1, currentPosition)
	}
	fmt.Println(currentPosition)
	fmt.Println(1000*(currentPosition[0]+101) + 4*(currentPosition[1]+51) + currentPosition[2])
}

func part2Parser(lines []string, fields [][][]rune, sidelength int) ([][][]rune, [][][]rune) {
	for i := 0; i < 4*sidelength; i += sidelength {
		field := [][]rune{}
		for j := i; j < i+sidelength; j++ {
			line := lines[j]
			if line == "" {
				break
			}
			fieldLine := strings.ReplaceAll(line, " ", "")
			field = append(field, []rune(fieldLine))
		}
		fields = append(fields, field)
	}
	cutFields := [][][]rune{}
	for i := 0; i < len(fields); i++ {
		field := fields[i]
		if len(field[0]) < 2*sidelength {
			cutFields = append(cutFields, field)
		} else {
			tmpFields := [2][][]rune{}
			for _, fieldLine := range field {
				tmpFields[0] = append(tmpFields[0], fieldLine[:sidelength])
				tmpFields[1] = append(tmpFields[1], fieldLine[sidelength:])
			}
			cutFields = append(cutFields, tmpFields[:]...)
		}
	}
	fmt.Println(len(cutFields))
	return fields, cutFields
}

func part1(lines []string, commands []string) {
	field := [][]rune{}
	for _, line := range lines {
		if line == "" {
			break
		}
		field = append(field, []rune(line))
	}
	fields := [][][]rune{field}
	currentPosition := [4]int{0, 0, 0, 0}
	for i, c := range field[0] {
		if c == '.' {
			currentPosition[1] = i
			break
		}
	}

	for _, command := range commands {
		currentPosition = runCommand(fields, command, currentPosition, false)
	}
	fmt.Println(1000*(currentPosition[0]+1) + 4*(currentPosition[1]+1) + currentPosition[2])
}

func runCommand(field [][][]rune, command string, currentPosition [4]int, part2 bool) [4]int {
	rotation := command[len(command)-1]
	if rotation < 57 {
		rotation = 0
	} else {
		command = command[:len(command)-1]
	}
	distance := helper.RemoveError(strconv.Atoi(command))
	currentPosition = move(field, currentPosition, distance, part2)
	currentPosition = rotate(rotation, currentPosition)

	return currentPosition
}

func rotate(rotation uint8, currentPosition [4]int) [4]int {
	if rotation == 'R' {
		newDirection := currentPosition[2] + 1
		if newDirection > 3 {
			newDirection = 0
		}
		currentPosition[2] = newDirection
	}
	if rotation == 'L' {
		newDirection := currentPosition[2] - 1
		if newDirection < 0 {
			newDirection = 3
		}
		currentPosition[2] = newDirection
	}
	return currentPosition
}

func getDirection(currentPosition [4]int) [2]int {
	directions := [][2]int{{0, 1}, {1, 0}, {0, -1}, {-1, 0}}
	return directions[currentPosition[2]]
}

func move(fields [][][]rune, currentPosition [4]int, distance int, part2 bool) [4]int {
	field := fields[0]
	direction := getDirection(currentPosition)
	for i := 0; i < distance; i++ {
		if part2 {
			field = fields[currentPosition[3]]
			direction = getDirection(currentPosition)
		}
		tmpPosition := [2]int{currentPosition[0], currentPosition[1]}
		tmpPosition[0] += direction[0]
		tmpPosition[1] += direction[1]
		check := checkPosition(field, tmpPosition)
		if check == 2 {
			break
		}
		if check == 1 {
			if !part2 {
				currentPosition = loop(field, currentPosition)
			} else {
				currentPosition = loopPart2(fields, currentPosition)
			}
		}
		if check == 0 {
			currentPosition[0] = tmpPosition[0]
			currentPosition[1] = tmpPosition[1]
		}
	}
	return currentPosition
}

//2  - Collision
//1  - Out Of Bounds
//0  - Fine
func checkPosition(field [][]rune, position [2]int) int {
	if position[0] >= len(field) || position[0] < 0 {
		return 1
	}
	if position[1] >= len(field[position[0]]) || position[1] < 0 {
		return 1
	}
	switch field[position[0]][position[1]] {
	case ' ':
		return 1
	case '.':
		return 0
	case '#':
		return 2
	}
	return -1
}

func loop(field [][]rune, currentPosition [4]int) [4]int {
	direction := getDirection(currentPosition)
	newStartPosition := [2]int{0, 0}
	if direction[0] == 0 {
		newStartPosition[0] = currentPosition[0]
	}
	if direction[0] < 0 {
		newStartPosition[0] = len(field) - 1
	}
	if direction[1] == 0 {
		newStartPosition[1] = currentPosition[1]
	}
	if direction[1] < 0 {
		newStartPosition[1] = len(field[newStartPosition[0]]) - 1
	}
	for checkPosition(field, newStartPosition) == 1 {
		newStartPosition[0] += direction[0]
		newStartPosition[1] += direction[1]
	}
	if checkPosition(field, newStartPosition) == 0 {
		currentPosition[0] = newStartPosition[0]
		currentPosition[1] = newStartPosition[1]
	}
	return currentPosition
}

func loopPart2(fields [][][]rune, currentPosition [4]int) [4]int {
	tmpPosition := getNewStartPos(currentPosition, len(fields[0][0]))
	field := fields[tmpPosition[3]]
	if checkPosition(field, [2]int{tmpPosition[0], tmpPosition[1]}) == 0 {
		return tmpPosition
	}
	return currentPosition
}

func getNewStartPos(currentPosition [4]int, sidelength int) [4]int {
	highestPos := sidelength - 1
	if currentPosition[3] == 0 {
		switch currentPosition[2] {
		case 0:
			currentPosition[3] = 1
			currentPosition[1] = 0
		case 1:
			currentPosition[3] = 2
			currentPosition[0] = 0
		case 2:
			currentPosition[3] = 3
			currentPosition[1] = 0
			currentPosition[0] = invertPosition(currentPosition[0], highestPos)
			currentPosition[2] = invertDirection(currentPosition[2])
		case 3:
			currentPosition[3] = 5
			currentPosition[0] = currentPosition[1]
			currentPosition[1] = 0
			currentPosition = rotate('R', currentPosition)
		}
		return currentPosition
	}
	if currentPosition[3] == 1 {
		switch currentPosition[2] {
		case 0:
			currentPosition[3] = 4
			currentPosition[0] = invertPosition(currentPosition[0], highestPos)
			currentPosition[1] = highestPos
			currentPosition[2] = invertDirection(currentPosition[2])
		case 1:
			currentPosition[3] = 2
			currentPosition[0] = currentPosition[1]
			currentPosition[1] = highestPos
			currentPosition = rotate('L', currentPosition)
		case 2:
			currentPosition[3] = 0
			currentPosition[1] = highestPos
		case 3:
			currentPosition[3] = 5
			currentPosition[0] = highestPos
		}
		return currentPosition

	}
	if currentPosition[3] == 2 {
		switch currentPosition[2] {
		case 0:
			currentPosition[3] = 1
			currentPosition[1] = currentPosition[0]
			currentPosition[0] = highestPos
			currentPosition = rotate('L', currentPosition)
		case 1:
			currentPosition[3] = 4
			currentPosition[0] = 0
		case 2:
			currentPosition[3] = 3
			currentPosition[1] = currentPosition[0]
			currentPosition[0] = 0
			currentPosition = rotate('L', currentPosition)
		case 3:
			currentPosition[3] = 0
			currentPosition[0] = highestPos
		}
		return currentPosition
	}
	if currentPosition[3] == 3 {
		switch currentPosition[2] {
		case 0:
			currentPosition[3] = 4
			currentPosition[1] = 0
		case 1:
			currentPosition[3] = 5
			currentPosition[0] = 0
		case 2:
			currentPosition[3] = 0
			currentPosition[0] = invertPosition(currentPosition[0], highestPos)
			currentPosition[1] = 0
			currentPosition[2] = invertDirection(currentPosition[2])
		case 3:
			currentPosition[3] = 2
			currentPosition[0] = currentPosition[1]
			currentPosition[1] = 0
			currentPosition = rotate('R', currentPosition)
		}
		return currentPosition
	}
	if currentPosition[3] == 4 {
		switch currentPosition[2] {
		//Potential Error
		case 0:
			currentPosition[3] = 1
			currentPosition[0] = invertPosition(currentPosition[0], highestPos)
			currentPosition[1] = highestPos
			currentPosition[2] = invertDirection(currentPosition[2])
		case 1:
			currentPosition[3] = 5
			currentPosition[0] = currentPosition[1]
			currentPosition[1] = highestPos
			currentPosition = rotate('R', currentPosition)
		case 2:
			currentPosition[3] = 3
			currentPosition[1] = highestPos
		case 3:
			currentPosition[3] = 2
			currentPosition[0] = highestPos
		}
		return currentPosition
	}
	if currentPosition[3] == 5 {
		switch currentPosition[2] {
		case 0:
			currentPosition[3] = 4
			currentPosition[1] = currentPosition[0]
			currentPosition[0] = highestPos
			currentPosition = rotate('L', currentPosition)
		case 1:
			currentPosition[3] = 1
			currentPosition[0] = 0
		case 2:
			currentPosition[3] = 0
			currentPosition[1] = currentPosition[0]
			currentPosition[0] = 0
			currentPosition = rotate('L', currentPosition)
		case 3:
			currentPosition[3] = 3
			currentPosition[0] = highestPos
		}
		return currentPosition
	}
	return currentPosition
}

func invertPosition(input int, highestPos int) int {
	return highestPos - input
}
func invertDirection(input int) int {
	if input > 1 {
		return input - 2
	} else {
		return input + 2
	}
}