AoC 2022 day 21

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

let startTime = performance.now()
let part1 = (part2 = 0)
let monkeys = []
let monkeys2 = []
fs.readFileSync(__dirname + "/data.txt", "utf8")
    .split(eol)
    .map((a) => {
        let [name, e] = a.split(": ")
        let num, m1, m2, op
        if (isNaN(e)) {
            ;[m1, op, m2] = e.split(" ")
        } else num = +e

        monkeys[name] = { name, num, m1, op, m2 }
        monkeys2[name] = { name, num, m1, op, m2 }
    })

function resolveMonkeys(monkey) {
    let m = monkeys[monkey]
    if (!isNaN(m.num)) return m.num
    m.m1 = resolveMonkeys(m.m1)
    m.m2 = resolveMonkeys(m.m2)
    if (m.op == "+") m.num = m.m1 + m.m2
    if (m.op == "-") m.num = m.m1 - m.m2
    if (m.op == "*") m.num = m.m1 * m.m2
    if (m.op == "/") m.num = m.m1 / m.m2
    return m.num
}

function createMonkeyEquation(monkey) {
    let m = monkeys2[monkey]
    if (!isNaN(m.num)) return m.num
    if (m.num == "y") return m.num
    m.m1 = createMonkeyEquation(m.m1)
    m.m2 = createMonkeyEquation(m.m2)
    return "(" + m.m1 + ")" + m.op + "(" + m.m2 + ")"
}

part1 = resolveMonkeys("root")
monkeys2.root.op = "="
monkeys2.humn.num = "y"
part2 = createMonkeyEquation("root")
// I solved part 2 by solving the resulting equation online :D
let time = performance.now() - startTime
console.log(`Part 1: ${part1}\nPart 2: ${part2}\nTimer: ${time} ms`)