adventofcode/2021/21/part2.mjs

43 lines
972 B
JavaScript

import fs from "fs-extra";
import fp from "lodash/fp.js";
import _ from "lodash";
import * as p1 from "./part1.mjs";
const cartesianProduct = (...rest) =>
rest.reduce(
(a, b) => a.flatMap((x) => b.map((y) => x.concat([y]))),
[[]]
);
const dimensions = cartesianProduct(
_.range(1, 4),
_.range(1, 4),
_.range(1, 4)
).map(fp.sum);
function resolveGame(p1, p2, s1, s2, f) {
let wins = 0;
let loses = 0;
dimensions.forEach((points) => {
const newPosition = (p1 + points) % 10;
const newScore = newPosition + 1 + s1;
if (newScore >= 21) {
wins++;
return;
}
const next = f(p2, newPosition, s2, newScore, f);
wins += next[1];
loses += next[0];
});
return [wins, loses];
}
export function solution(positions) {
const res = _.memoize(resolveGame, (...args) => args.join("-"));
return Math.max(...res(...positions, 0, 0, res));
}