adventofcode/2022/11/part1.js

72 lines
1.7 KiB
JavaScript

import * as R from "remeda";
import { readFile } from "../05/part1.js";
function parseMonkey(block) {
const re = new RegExp(
`Starting items: (?<items>.+)
Operation: new = (?<operation>.+)
Test: divisible by (?<divisible>\\d+)
If true: throw to monkey (?<ifTrue>\\d+)
If false: throw to monkey (?<ifFalse>\\d+)`,
"s"
);
const groups = { ...block.match(re).groups };
["divisible", "ifTrue", "ifFalse"].forEach(
(k) => (groups[k] = parseInt(groups[k]))
);
groups.operation = eval("(old) => " + groups.operation);
groups.items = groups.items.split(", ").map((x) => parseInt(x));
return { ...groups, inspections: 0 };
}
const readInput = (...args) =>
R.pipe(
readFile(...args),
(lines) => lines.split("\n\n"),
R.compact, // remove last line
R.map(parseMonkey)
);
export const puzzleInput = readInput(import.meta.url, "input");
export const sample = readInput(import.meta.url, "sample");
const playTurn = (monkeys, monkey) => {
monkey.inspections += monkey.items.length;
monkey.items = monkey.items.map( i => monkey.operation(i) );
monkey.items = monkey.items.map( i => Math.floor(i/3) );
monkey.items.forEach( i => {
monkeys[(i % monkey.divisible) ? monkey.ifFalse : monkey.ifTrue
].items.push(i)
} )
monkey.items = [];
return;
};
const playRound = (monkeys) => {
monkeys.forEach( monkey => playTurn(monkeys,monkey) );
return monkeys;
}
export default R.createPipe(
R.clone,
(monkeys) => R.times(20, () => playRound(monkeys)),
R.last(),
R.map( R.prop('inspections') ),
R.sortBy( R.identity ),
R.reverse,
R.take(2),
R.reduce( (a,b) => a * b, 1 )
)