advent2022/d9/main.js

const fs = require('fs');
const readline = require('readline');

function Rope(len) {
    this.tokens = [];
    this.visited = {'0x0': true};
    this.visitedCoord = [[0, 0]];
    this.boundaries = [[0, 0], [0, 0]];
    this.len = len;
    for (let i =0; i < len +1; ++i)
        this.tokens.push([0, 0]);
}

Rope.prototype.applyMove = function(moveArr) {
    this.tokens[0][0] += moveArr[0];
    this.tokens[0][1] += moveArr[1];
    this.boundaries = [
        [ Math.min(this.boundaries[0][0], this.tokens[0][0]), Math.max(this.boundaries[0][1], this.tokens[0][0]) ],
        [ Math.min(this.boundaries[1][0], this.tokens[0][1]), Math.max(this.boundaries[1][1], this.tokens[0][1]) ],
    ];
    for (let i =0; i < this.tokens.length -1; ++i)
        this.checkAndMove(i);
    this.visited[this.tokens[this.tokens.length -1][0] + 'x' +this.tokens[this.tokens.length -1][1]] = true;
    this.visitedCoord.push([this.tokens[this.tokens.length -1][0], this.tokens[this.tokens.length -1][1]]);
}

Rope.prototype.checkAndMove = function(headPos) {
    if (Math.abs(this.tokens[headPos][0] - this.tokens[headPos +1][0]) <= 1 &&
        Math.abs(this.tokens[headPos][1] - this.tokens[headPos+1][1]) <= 1)
        return;
    if (this.tokens[headPos +1][1] !== this.tokens[headPos][1])
        this.tokens[headPos +1][1] += (this.tokens[headPos +1][1] < this.tokens[headPos][1]) ? 1 : -1;
    if (this.tokens[headPos +1][0] !== this.tokens[headPos][0])
        this.tokens[headPos +1][0] += (this.tokens[headPos +1][0] < this.tokens[headPos][0]) ? 1 : -1;
}

const COLORS = [ '\033[39m', '\033[31m', '\033[32m', '\033[33m', '\033[34m', '\033[35m', '\033[36m' ]

function showRope(arenaSize, ropeItems) {
    // clear screen
    for (let i =0; i < 5; ++i) console.log();
    // /clear screen

    console.log('\x1Bc');
    let item = ropeItems.shift();
    for (let py =0; py < arenaSize[1]; ++py) {
        let line = '';
        for (let px =0; px < arenaSize[0]; ++px) {
            if (item && item.x === px && item.y === py) {
                line += COLORS[item.color] + item.c + COLORS[0];
                item = ropeItems.shift();
            } else {
                line += '.';
            }
        }
        console.log(line);
    }
}

function prepShowRope(arenaSize, arenaShift, replayRope) {
    showRope(arenaSize, replayRope.tokens
        .map((i, index) => { return {
            x: i[0]+arenaShift[0],
            y: i[1]+arenaShift[1],
            c: '#',
            color: index+1 >= COLORS.length ? Math.ceil(Math.random() * (COLORS.length-1)) : (index +1)
        };}).concat(
            replayRope.visitedCoord.map(i => { return {
                x: i[0] + arenaShift[0],
                y: i[1] + arenaShift[1],
                c: '"',
                color: 0
            };})
        )
        .sort((a, b) => {
            if (a.x === b.x && a.y === b.y)
                return a.c === '"' ? 1 : -1;
            if (a.y === b.y)
                return a.x-b.x;
            return a.y-b.y;
        })
        .filter((value, index, self) => self.findIndex(i => i.x === value.x && i.y === value.y) === index));
}

function mSleep() {
    return new Promise(ok => setTimeout(ok, 90));
}

async function showReplay(rope, actions) {
    let arenaSize = [ rope.boundaries[0][1] - rope.boundaries[0][0] +1, rope.boundaries[1][1] - rope.boundaries[1][0] +1];
    let arenaShift = [ -rope.boundaries[0][0], -rope.boundaries[1][0] ];
    let replayRope = new Rope(rope.len);

    await prepShowRope(arenaSize, arenaShift, replayRope);
    for (let i of actions) {
        await mSleep();
        replayRope.applyMove(i);
        prepShowRope(arenaSize, arenaShift, replayRope);
    }
}

async function main() {
    const move = {
        'U': [0, -1],
        'D': [0, 1],
        'L': [-1, 0],
        'R': [1, 0]
    };
    let tokens = new Rope(1);
    let tokensPart2 = new Rope(10);
    let moveList = [];
    for await (let line of readline.createInterface({ input: process.stdin })) {
        if (!line || !line.length)
            continue;
        let reg = /([UDLR]) (\d+)/.exec(line);
        for (let i =0; i < reg[2]; ++i) {
            moveList.push(move[reg[1]]);
            tokens.applyMove(move[reg[1]]);
            tokensPart2.applyMove(move[reg[1]]);
        }
    }
    await showReplay(tokensPart2, moveList);

    console.log("Part 1: ", Object.keys(tokens.visited).length);
    console.log("Part 2: ", Object.keys(tokensPart2.visited).length);
};

(main());