advent2022/d05/main.js

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

function Stack() {
    this.data = [];
    this.id = 0;
}
Stack.prototype.push = function(letter) {
    if (letter !== ' ')
        this.data.push(letter);
}
Stack.prototype.multiPush = function(arr) {
    this.data = arr.concat(this.data);
}
Stack.prototype.log = function() {
    console.log(this.id, this.data);
}
Stack.prototype.moveTo = function(count, targetStack) {
    //targetStack.multiPush(this.data.splice(0, count).reverse()); // Part 1
    targetStack.multiPush(this.data.splice(0, count)); // part 2
}
Stack.prototype.finalize = function() {
    this.id = parseInt(this.data.pop());
}

async function main() {
    let stacks = null;
    let stackDefined = false;

    for await (let line of readline.createInterface({ input: process.stdin })) {
        if ((!line || !line.length) && !stackDefined) {
            stackDefined = true;
            stacks.forEach(i => i.finalize());
            continue;
        }
        if (!stackDefined) {
            if (!stacks) {
                stacks = [];
                for (let i =0; i < line.length / 4; ++i)
                    stacks.push(new Stack());
            }
            for (let i =0; i < line.length /4; ++i) {
                stacks[i].push(line[i*4+1]);
            }
        } else {
            if (!line || !line.length)
                break;
            let num = [];
            for (let i of line.matchAll(/\d+/g)) num.push(i[0]);
            stacks[num[1] -1].moveTo(num[0], stacks[num[2] -1]);
        }
    }
    stacks.forEach(i => i.log());
    console.log(stacks.map(i => i.data[0] || null).filter(i => !!i).join(""));
};

(main());