adventofcode/2022/day17/main.go

package main

import (
	"fmt"
	"os"
	"time"

	h "git.bullercodeworks.com/brian/adventofcode/helpers"
)

const (
	dirU = iota
	dirR
	dirD
	dirL

	rocks = 5

	debug = false
)

var (
	emptyRow  = []byte{'|', ' ', ' ', ' ', ' ', ' ', ' ', ' ', '|'}
	bottomRow = []byte{'+', '-', '-', '-', '-', '-', '-', '-', '+'}
)

func main() {
	inp := h.StdinToString()
	//fmt.Println("# Part 1")
	//simulate(inp, 2022)
	fmt.Println("# Part 2")
	simulate(inp, 1000000000000)
}

func stateAndSleep(m *h.GrowUpCoordByteMap) {
	if !debug {
		return
	}
	fmt.Print(h.CLEAR_SCREEN)
	//fmt.Println()
	fmt.Println(m)
	time.Sleep(time.Second / 10)
}

var cache map[string][]int

func simulate(jets string, numRocks int) {
	cache = make(map[string][]int)
	m := h.NewGrowUpCoordByteMap()
	m.PutBytes([][]byte{
		bottomRow, emptyRow, emptyRow, emptyRow, emptyRow,
		emptyRow, emptyRow, emptyRow,
	}, h.Coordinate{X: 0, Y: 0})
	m.StringEmptyIsSpace = true

	jetIdx := 0
	rockType := 0
	var state string
	var height int
	var turboHeight int
	var cacheDisabled bool
	for rockNum := 1; rockNum <= numRocks; rockNum++ {
		fmt.Println(h.CLEAR_SCREEN)
		fmt.Println("Simulating:", rockNum, "/", numRocks)
		h.PrintProgress(rockNum, numRocks)
		fmt.Println("\nHeight:", height)
		if !cacheDisabled {
			state, height = GetState(rockType, jetIdx, m)
			if v, ok := cache[state]; !cacheDisabled && ok {
				// Ok, we've got a duplicate. Go full turbo.
				//addHeight := height
				mult := numRocks / rockNum
				newRockNum := rockNum * mult
				turboHeight = height * mult
				/*
					for rockNum+v[1] <= numRocks {
						rockNum = rockNum + v[1]
						height = height + addHeight
						fmt.Println(h.CLEAR_SCREEN)
						fmt.Println("Simulating:", rockNum, "/", numRocks)
						h.PrintProgress(rockNum, numRocks)
						fmt.Println("\nHeight:", height)
					}
				*/
				fmt.Println(h.CLEAR_SCREEN)
				fmt.Println("Simulating:", rockNum, "/", numRocks)
				h.PrintProgress(rockNum, numRocks)
				fmt.Println("\nHeight:", height)
				fmt.Println("State", state, "\nV:", v, "\nMult:", mult, "\nRockNum:", rockNum, "\nNewRockNum:", newRockNum, "\nTurboHeight:", turboHeight)
				cacheDisabled = true
				os.Exit(0)
			} else {
				cache[state] = []int{rockNum, height}
			}
		} else {
			fmt.Println("\nHeight:", turboHeight+GetHeight(m))
		}
		AddFallingRock(rockType, m)
		stateAndSleep(m)
		doJet := true
		for {
			if !doJet && AtRest(m) {
				break
			}
			shiftDir := dirD
			if doJet {
				switch jets[jetIdx] {
				case '>':
					shiftDir = dirR
				case '<':
					shiftDir = dirL
				}
				jetIdx = (jetIdx + 1) % len(jets)
			}
			ShiftRock(shiftDir, m)
			stateAndSleep(m)
			doJet = !doJet
		}
		// The falling rock has stopped
		StopRock(m)
		stateAndSleep(m)
		rockType = (rockType + 1) % rocks
	}
	fmt.Println("After", numRocks, "the tower is", GetHeight(m), "blocks tall")
}

func GetState(r, j int, m *h.GrowUpCoordByteMap) (string, int) {
	ret := fmt.Sprintf("%d;%d;", r, j)
	for x := 1; x < 7; x++ {
		for y := m.TLY; y > 1; y-- {
			if m.Get(h.Coordinate{X: x, Y: y}) == '#' {
				ret = fmt.Sprintf("%s-%d", ret, m.TLY-y)
				break
			}
		}
	}
	return ret, GetHeight(m)
}

func GetHeight(m *h.GrowUpCoordByteMap) int {
	return h.GetHighestY(m.FindAll('#')...)
}

func FindTopAtRestY(m *h.GrowUpCoordByteMap) int {
	rockSpots := m.FindAll('#')
	if len(rockSpots) != 0 {
		return h.GetHighestY(rockSpots...)
	}
	return 0
}

func StopRock(m *h.GrowUpCoordByteMap) {
	rockSpots := m.FindAll('@')
	for i := range rockSpots {
		m.Put(rockSpots[i], '#')
	}
}
func ShiftRock(dir int, m *h.GrowUpCoordByteMap) {
	if !CanShift(dir, m) {
		return
	}

	rockSpots := m.FindAll('@')
	for i := range rockSpots {
		m.Put(rockSpots[i], ' ')
	}
	for i := range rockSpots {
		switch dir {
		case dirU:
			m.Put(GetUp(rockSpots[i]), '@')
		case dirR:
			m.Put(GetRight(rockSpots[i]), '@')
		case dirD:
			m.Put(GetDown(rockSpots[i]), '@')
		case dirL:
			m.Put(GetLeft(rockSpots[i]), '@')
		}
	}
}
func CanShift(dir int, m *h.GrowUpCoordByteMap) bool {
	rockSpots := m.FindAll('@')
	switch dir {
	case dirU: // Shouldn't need to, though.
		return true
	case dirR:
		for i := range rockSpots {
			tst := m.Get(GetRight(rockSpots[i]))
			if tst != '@' && tst != ' ' {
				return false
			}
		}
		return true
	case dirD:
		for i := range rockSpots {
			tst := m.Get(GetDown(rockSpots[i]))
			if tst != '@' && tst != ' ' {
				return false
			}
		}
		return true
	case dirL:
		for i := range rockSpots {
			tst := m.Get(GetLeft(rockSpots[i]))
			if tst != '@' && tst != ' ' {
				return false
			}
		}
		return true
	}
	return false
}
func AddFallingRock(tp int, m *h.GrowUpCoordByteMap) {
	rock := GetRockBytes(tp)
	pos := h.Coordinate{X: 3, Y: FindTopAtRestY(m) + 4}
	for pos.Y+3 > m.TLY {
		m.PutBytes([][]byte{emptyRow}, h.Coordinate{X: 0, Y: m.TLY + 1})
	}
	m.PutBytes(rock, pos)
}
func AtRest(m *h.GrowUpCoordByteMap) bool {
	rockSpots := m.FindAll('@')
	if len(rockSpots) == 0 {
		return true
	}
	for i := range rockSpots {
		pos := GetDown(rockSpots[i])
		wrk := m.Get(pos)
		if pos.Y == m.BRY {
			return true
		}
		if wrk != ' ' && wrk != '@' {
			return true
		}
	}
	return false
}

func GetRockBytes(tp int) [][]byte {
	switch tp {
	case 0:
		return [][]byte{{'@', '@', '@', '@'}}
	case 1:
		return [][]byte{
			{' ', '@', ' '},
			{'@', '@', '@'},
			{' ', '@', ' '},
		}
	case 2:
		return [][]byte{
			{'@', '@', '@'},
			{' ', ' ', '@'},
			{' ', ' ', '@'},
		}
	case 3:
		return [][]byte{
			{'@'},
			{'@'},
			{'@'},
			{'@'},
		}
	case 4:
		return [][]byte{
			{'@', '@'},
			{'@', '@'},
		}
	}
	return [][]byte{}
}

func GetLeft(c h.Coordinate) h.Coordinate {
	return h.Coordinate{X: c.X - 1, Y: c.Y}
}
func GetRight(c h.Coordinate) h.Coordinate {
	return h.Coordinate{X: c.X + 1, Y: c.Y}
}
func GetUp(c h.Coordinate) h.Coordinate {
	return h.Coordinate{X: c.X, Y: c.Y + 1}
}
func GetDown(c h.Coordinate) h.Coordinate {
	return h.Coordinate{X: c.X, Y: c.Y - 1}
}
func DirToString(shiftDir int) string {
	switch shiftDir {
	case dirU:
		return "^"
	case dirR:
		return ">"
	case dirD:
		return "v"
	case dirL:
		return "<"
	}
	return " "
}