AdventOfCode-js-2019/12/12_1.js

const Moon = require("./Moon");
const { step, parseInput } = require("./common");

const input = parseInput([
    "<x=14, y=15, z=-2>",
    "<x=17, y=-3, z=4>",
    "<x=6, y=12, z=-13>",
    "<x=-2, y=10, z=-8>",
]);

const tests = parseInput([
    "<x=-1, y=0, z=2>",
    "<x=2, y=-10, z=-7>",
    "<x=4, y=-8, z=8>",
    "<x=3, y=5, z=-1>",
]);

const STEPS = 1000;

for (let i = 0; i < STEPS; i++) {
    step(input);
}

console.log(`Total energy in system is: ${calculateTotalEnergy(input)}`);

/**
 * Calculate the total energy in the system
 *
 * The total energy in the system is the sum of the sum of the positional
 * values multiplied by the sum of the velocity values.
 *
 * @param {Moon[]} moons The moons in the system
 * @returns {number} The total energy in the system
 */
function calculateTotalEnergy(moons) {
    let energy = 0;

    for (const moon of moons) {
        const potentialEnergy = Math.abs(moon.position.x) + Math.abs(moon.position.y) + Math.abs(moon.position.z);
        const kineticEnergy = Math.abs(moon.velocity.x) + Math.abs(moon.velocity.y) + Math.abs(moon.velocity.z);
        energy += potentialEnergy * kineticEnergy;
    }

    return energy;
}