34 lines
947 B
JavaScript
34 lines
947 B
JavaScript
import * as fs from "fs";
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const ENTRY_REGEX = /^(\d+?)-(\d+?) (\w?): (\w+)$/;
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/**
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* Main function for Puzzle A
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*
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* @param {string} data Puzzle input as a single string.
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* @returns {number} Amount of valid passwords in puzzle input.
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*/
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async function main(data) {
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const lines = data.split("\n").map((line) => line.trim());
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const pass_data = lines.map((line) => line.match(ENTRY_REGEX));
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let valid_passwords = [];
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for (const entry of pass_data) {
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if (!entry) throw new Error(`Failed to parse some data. ${entry}`);
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const index1 = parseInt(entry[1]) - 1;
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const index2 = parseInt(entry[2]) - 1;
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const char = entry[3];
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const pass = entry[4];
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if ((pass[index1] === char) !== (pass[index2] === char)) {
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valid_passwords.push(entry);
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}
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}
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return valid_passwords.length;
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}
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fs.readFile("input", (err, data) => {
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if (err) throw err;
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main(data.toString()).then(console.log).catch(console.error);
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});
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