adventofcode/2021/03/part1.mjs
2021-12-05 11:44:51 -05:00

26 lines
695 B
JavaScript

import fs from "fs-extra";
import fp from "lodash/fp.js";
import _ from "lodash";
export const processFile = async (f) =>
fs
.readFile(f, "utf8")
.then((x) => x.split("\n").filter((x) => x))
.then((lines) =>
lines.map((l) => l.split("").map((x) => parseInt(x)))
);
const mostCommon = (numbers) => (_.sum(numbers) * 2 > numbers.length ? 1 : 0);
export const toDecimal = (numbers) => numbers.reduce((a, x) => a * 2 + x, 0);
export const solution = (entries) => {
const groups = _.zip(...entries).map(mostCommon);
const gamma = toDecimal(groups);
const epsilon = toDecimal(groups.map((x) => 1 - x));
return gamma * epsilon;
};