advent2022/d07/main.js

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

function computeSize(directories, root) {
    let sum = 0;
    if (directories[root].size)
        return directories[root].size;
    for (let i of directories[root].content) {
        if (i.size === null)
            i.size = computeSize(directories, path.join(root, i.name));
        sum += i.size;
    }
    directories[root].size = sum;
    return sum;
}

async function main() {
    let wd = '/';
    let currentDirContent = null;
    let allDirectories = {};
    for await (let line of readline.createInterface({ input: process.stdin })) {
        if (!line || !line.length)
            break;
        if (line.startsWith('$')) {
            if (currentDirContent) {
                allDirectories[wd] = { size: null, content: currentDirContent };
                currentDirContent = null;
            }
            if (line === '$ ls')
                currentDirContent = [];
            else if (line.startsWith('$ cd '))
                wd = path.join(wd, line.substring(4).trim())
        } else if (currentDirContent) {
            let l = line.split(" ");
            const size = parseInt(l.shift());
            currentDirContent.push({
                size: isNaN(size) ? null : size,
                isDir: isNaN(size),
                name: l.join(" ")
            });
        }
    }
    if (currentDirContent)
        allDirectories[wd] = { size: null, content: currentDirContent };
    computeSize(allDirectories, '/');

    // Part 1
    console.log(Object.keys(allDirectories).map(i => allDirectories[i].size).filter(i => i < 100000).reduce((tmp, i) => tmp + i));
    // Part 2
    console.log(Object.keys(allDirectories).map(i => allDirectories[i].size).filter(i => i >= allDirectories['/'].size-40000000).reduce((tmp, i) => Math.min(tmp, i)));
};

(main());