AoC 2022 day 17

const fs = require("fs")
const performance = require("perf_hooks").performance
const eol = require("os").EOL

let startTime = performance.now()
let part1 = (part2 = 0)
let input = fs
    .readFileSync(__dirname + "/data.txt", "utf8")
    .split(eol)
    .join("")
    .split("")
let chamber = [["#", "#", "#", "#", "#", "#", "#", "#", "#"]]
let segment = ["#", ".", ".", ".", ".", ".", ".", ".", "#"]

let bloks = [
    [["#", "#", "#", "#"]],
    [
        [".", "#", "."],
        ["#", "#", "#"],
        [".", "#", "."]
    ],
    [
        ["#", "#", "#"],
        [".", ".", "#"],
        [".", ".", "#"]
    ],
    [["#"], ["#"], ["#"], ["#"]],
    [
        ["#", "#"],
        ["#", "#"]
    ]
]
let steps = 1000000000000
let blockIndex = 0
let numBlocks = bloks.length
let numjets = input.length
let topIndex = 1
let jetIndex = 0

function colides(block, blockX, blockY) {
    return block.some((r, y) => {
        return r.some((state, x) => {
            return state == "#" && chamber[blockY + y][blockX + x] == "#"
        })
    })
}

function checkRepeat() {
    let l = topIndex - 1
    let max = ~~(chamber.length / 2) - 5
    let len = max
    for (len; len > input.length / 5; len--) {
        let same = true
        for (let i = 0; i < len; i++) {
            if (!chamber[l - i].every((el, ix) => el === chamber[l - (i + len)][ix])) {
                same = false
                break
            }
        }
        if (same) {
            return len
        }
    }
    return -1
}
let repeatFound = false
let repeatLength = 0
let repeatNext = 0
let repeatStep = 0
let mult = 0
while (steps--) {
    let block = bloks[blockIndex]
    let blockHeight = block.length
    let blockY = topIndex + 3
    let blockX = 3
    while (blockY + blockHeight > chamber.length) {
        chamber.push(segment.slice())
    }

    while (true) {
        let jet = input[jetIndex++ % numjets] == "<" ? -1 : +1
        if (!colides(block, blockX + jet, blockY)) blockX += jet
        if (!colides(block, blockX, blockY - 1)) {
            blockY--
        } else {
            block.forEach((r, y) => {
                r.forEach((state, x) => {
                    if (state == "#") chamber[blockY + y][blockX + x] = state
                })
            })
            topIndex = Math.max(blockY + blockHeight, topIndex)
            break
        }
    }
    if (mult === 0) {
        if (!repeatFound) {
            let repeat = checkRepeat()
            if (repeat != -1) {
                repeatFound = true
                repeatNext = topIndex + repeat
                repeatLength = repeat
                repeatStep = steps
            }
        } else if (repeatNext == topIndex) {
            repeatStep = repeatStep - steps
            mult = Math.floor(steps / repeatStep)
            let rest = steps % repeatStep
            steps = rest
        }
    }
    if (1000000000000 - steps == 2022) part1 = topIndex - 1
    if (++blockIndex == numBlocks) blockIndex = 0
}
part2 = topIndex - 1 + mult * repeatLength
let time = performance.now() - startTime
console.log(`Part 1: ${part1}\nPart 2: ${part2}\nTimer: ${time} ms`)