99 lines
3.0 KiB
TypeScript
99 lines
3.0 KiB
TypeScript
import { collectArray, inputLines, measureDuration } from "./common.ts";
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const input = await collectArray(await inputLines("3"));
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type SubmarineCommand = ["forward", number] | ["up", number] | ["down", number];
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type Counters = [zeroCount: number, oneCount: number][];
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const ASCII_ZERO = "0".charCodeAt(0);
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function countBits(
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input: string[],
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width?: number,
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windowWidth?: number,
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): Counters {
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if (!width) width = input[0].length;
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if (!windowWidth) windowWidth = width;
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const counter: Counters = Array.from(Array(width), (_) => [0, 0]);
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for (const l of input) {
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for (let i = width - windowWidth; i < width; i++) {
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const val = l.charCodeAt(i) - ASCII_ZERO;
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counter[i][val]++;
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}
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}
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return counter;
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}
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export function part1(input: string[]): number {
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const width = input[0].length;
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const counter = countBits(input);
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const ones = [...Array(width).keys()].reduce((acc, i) =>
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acc += (counter[i][1] >= counter[i][0]) ? (1 << i) : 0
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);
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// xor with a mask the same size as the width to get the zeroes value
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console.log("oz:", ones);
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return ones * (ones ^ (Math.pow(2, width) - 1));
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}
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await measureDuration(() => console.log("Part 1", part1(input)));
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export function part2(input: string[]): number {
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// I hate this.
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const width = input[0].length;
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const counter = Array.from(Array(width), (_) => [0, 0]);
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for (const l of input) {
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for (let i = 0; i < width; i++) {
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const val = l.charCodeAt(i) - ASCII_ZERO;
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counter[i][val]++;
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}
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}
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let oxyGenRating = null;
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let coScrubRating = null;
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let oxyGenCandidates = input.slice(0);
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let coScrubCandidates = input.slice(0);
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for (let i = 0; i < width; i++) {
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const newOxyGenCandidates: string[] = [];
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const newCoScrubCandidates: string[] = [];
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// console.log(counter[i]);
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const moreCommon = (counter[i][1] > counter[i][0] ? 1 : 0).toString();
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// console.log(i, width, moreCommon);
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if (!oxyGenRating) {
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for (const binnum of oxyGenCandidates) {
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if (binnum[i] == moreCommon) newOxyGenCandidates.push(binnum);
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}
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if (newOxyGenCandidates.length == 1) {
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oxyGenRating = parseInt(newOxyGenCandidates[0], 2);
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/*
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console.log(
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"Oxygen Generator Rating:",
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oxyGenRating,
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oxyGenCandidates,
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newOxyGenCandidates,
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);
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*/
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} else oxyGenCandidates = newOxyGenCandidates;
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// console.log(oxyGenCandidates);
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}
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if (!coScrubRating) {
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for (const binnum of coScrubCandidates) {
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if (binnum[i] != moreCommon) newCoScrubCandidates.push(binnum);
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}
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if (newCoScrubCandidates.length == 1) {
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coScrubRating = parseInt(newCoScrubCandidates[0], 2);
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/*
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console.log(
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"CO2 Scrubber Rating:",
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coScrubRating,
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coScrubCandidates,
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newCoScrubCandidates,
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);
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*/
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} else coScrubCandidates = newCoScrubCandidates;
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// console.log(coScrubCandidates);
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}
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}
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return (oxyGenRating || 0) * (coScrubRating || 0);
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}
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// await measureDuration(() => console.log("Part 2", part2(input)));
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