AOC2022/day17/day17.go

package main

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

type Field struct {
	field         [][]rune
	currentBlock  Block
	spawnedBlocks int
}

type Block struct {
	form     [][2]int
	position [2]int
}

func main() {
	args := os.Args[1:]
	lines := helper.ReadTextFile(args[0])
	field := Field{createField(), Block{}, 0}
	field.addBlock()
	fieldCopy := Field{createField(), Block{}, 0}
	fieldCopy.addBlock()
	heightForBlocks := part1(fieldCopy, lines)
	currentPrefix := 0
	currentCycle := 1
	finished := false
	for !finished {
		if currentPrefix < currentCycle {
			currentPrefix++
		} else {
			currentPrefix = 0
			currentCycle++
		}
		fieldCopy = Field{createField(), Block{}, 0}
		fieldCopy.addBlock()
		finished = checkCycle(currentPrefix, currentCycle, heightForBlocks)
	}
	fmt.Println(currentCycle)

	part2(currentPrefix, currentCycle, field, lines)

}

func checkCycle(prefix, cycle int, heightForBlocks map[int]int) bool {
	cycleHeight := heightForBlocks[cycle+prefix] - heightForBlocks[prefix]
	for i := prefix; i < len(heightForBlocks); i += cycle {
		if !(heightForBlocks[i+cycle]-heightForBlocks[i] == cycleHeight) {
			return false
		}
	}
	return true
}

func part2(prefix, cycle int, field Field, lines []string) {
	suffix := (1000000000000 - prefix) % cycle
	prefixHeight := 0
	cycleHeight := 0
	suffixHeight := 0
	currentJetMove := 0
	for field.spawnedBlocks != 3*cycle+prefix {
		field.move(rune(lines[0][currentJetMove]))
		if field.spawnedBlocks == prefix+1 {
			prefixHeight = (len(field.field) - field.getLineWithHighestRock())
		}
		if field.spawnedBlocks == prefix+cycle+1 {
			cycleHeight = (len(field.field) - field.getLineWithHighestRock()) - prefixHeight
		}
		if field.spawnedBlocks == cycle+prefix+suffix+1 {
			suffixHeight = (len(field.field) - field.getLineWithHighestRock()) - cycleHeight - prefixHeight
		}
		currentJetMove++
		if currentJetMove == len(lines[0]) {
			currentJetMove = 0
		}
	}
	fmt.Println(((1000000000000 - prefix) / cycle * cycleHeight) + prefixHeight + suffixHeight)
}

func part1(field Field, lines []string) (heightForBlocks map[int]int) {
	heightForBlocks = make(map[int]int)
	currentJetMove := 0
	solutionPart1 := 0
	for field.spawnedBlocks != 50000 {
		field.move(rune(lines[0][currentJetMove]))
		if field.spawnedBlocks == 2023 {
			solutionPart1 = len(field.field) - field.getLineWithHighestRock()
		}
		heightForBlocks[field.spawnedBlocks] = len(field.field) - field.getLineWithHighestRock()
		currentJetMove++
		if currentJetMove == len(lines[0]) {
			currentJetMove = 0
		}
	}
	fmt.Printf("%v : %v \n", field.spawnedBlocks, solutionPart1)
	return
}

func getNewBlock(spawnedBlocks int) Block {
	lineBlock := [][2]int{{0, 0}, {0, 1}, {0, 2}, {0, 3}}
	crossBlock := [][2]int{{0, 1}, {1, 1}, {1, 0}, {1, 2}, {2, 1}}
	lBlock := [][2]int{{2, 0}, {2, 1}, {2, 2}, {1, 2}, {0, 2}}
	iBlock := [][2]int{{0, 0}, {1, 0}, {2, 0}, {3, 0}}
	squareBlock := [][2]int{{0, 0}, {0, 1}, {1, 1}, {1, 0}}
	blocks := [][][2]int{lineBlock, crossBlock, lBlock, iBlock, squareBlock}
	blockForm := blocks[(spawnedBlocks)%5]
	return Block{blockForm, [2]int{0, 2}}
}

func (field *Field) move(exhaust rune) {
	direction := [2]int{0, 0}
	switch exhaust {
	case '<':
		direction[1] = -1
	case '>':
		direction[1] = +1
	}
	field.moveBlock(direction)
	oldPos := field.currentBlock.position
	field.moveBlock([2]int{1, 0})
	if oldPos == field.currentBlock.position {
		field.writeBlockToField()
		field.addBlock()
	}
}

func (field *Field) writeBlockToField() {
	currentBlockPoints := field.getCurrentBLockPoints()
	for _, point := range currentBlockPoints {
		field.field[point[0]][point[1]] = '#'
	}
}

func (field *Field) getCurrentBLockPoints() [][2]int {
	curretnPoints := [][2]int{}
	for _, point := range field.currentBlock.form {
		blocPoint := [2]int{point[0] + field.currentBlock.position[0], point[1] + field.currentBlock.position[1]}
		curretnPoints = append(curretnPoints, blocPoint)
	}
	return curretnPoints
}

func (field *Field) moveBlock(direction [2]int) {
	possibleNewPos := addPosition(field.currentBlock.position, direction)
	for _, point := range field.currentBlock.form {
		pointToCheck := [2]int{point[0] + possibleNewPos[0], point[1] + possibleNewPos[1]}
		if pointToCheck[0] >= len(field.field) {
			return
		}
		if pointToCheck[1] >= len(field.field[pointToCheck[0]]) || pointToCheck[1] < 0 {
			return
		}
		if field.field[pointToCheck[0]][pointToCheck[1]] == '#' {
			return
		}
	}
	field.currentBlock.position = possibleNewPos
}

func addPosition(a [2]int, b [2]int) [2]int {
	return [2]int{a[0] + b[0], a[1] + b[1]}
}

func (field *Field) addBlock() {
	//if (field.spawnedBlocks-25)%35 == 0 {
	//	fmt.Printf("%v : %v \n", field.spawnedBlocks, (len(field.field) - field.getLineWithHighestRock()))
	//}

	lineWithHighestRock := field.getLineWithHighestRock()
	field.field = field.field[lineWithHighestRock:]
	field.currentBlock = getNewBlock(field.spawnedBlocks)
	blockHeight := field.currentBlock.getBlockHeight()
	field.addLines(3 + blockHeight)
	field.spawnedBlocks++
}

func (block Block) getBlockHeight() int {
	height := 0
	for _, pos := range block.form {
		if pos[0] > height {
			height = pos[0]
		}
	}
	return height + 1
}

func (field *Field) getLineWithHighestRock() int {
	for i, line := range field.field {
		for _, elem := range line {
			if elem == '#' {
				return i
			}
		}
	}
	return len(field.field)
}

func (field *Field) addLines(n int) {
	newLines := [][]rune{}
	for i := 0; i < n; i++ {
		fieldLine := []rune{}
		for j := 0; j < 7; j++ {
			fieldLine = append(fieldLine, '.')
		}
		newLines = append(newLines, fieldLine)
	}
	newLines = append(newLines, field.field...)
	field.field = newLines
}

func createField() [][]rune {
	field := [][]rune{}
	for i := 0; i < 4; i++ {
		fieldLine := []rune{}
		for j := 0; j < 7; j++ {
			fieldLine = append(fieldLine, '.')
		}
		field = append(field, fieldLine)
	}
	return field
}

func (field Field) printField() {
	currentBlockPoints := field.getCurrentBLockPoints()
	fieldCopy := make([][]rune, len(field.field))
	for i := range field.field {
		fieldCopy[i] = make([]rune, len(field.field[i]))
		copy(fieldCopy[i], field.field[i])
	}
	for _, point := range currentBlockPoints {
		fieldCopy[point[0]][point[1]] = '@'
	}
	for i := 0; i < len(fieldCopy); i++ {
		fmt.Println(string(fieldCopy[i]))
	}
	fmt.Println()
}