57 lines
1.5 KiB
JavaScript
57 lines
1.5 KiB
JavaScript
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import fs from "fs";
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/**
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* Main function for Puzzle A
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*
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* @param {number[]} numbers - Parsed puzzle input.
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* @returns {[index: number, value: number]} Index and value of the first number that can't be made by adding any of the previous 25.
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*/
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async function partA(numbers) {
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number_loop: for (let i = 25; i < numbers.length; i++) {
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for (let a = i - 25; a < i; a++) {
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for (let b = a + 1; b < i; b++) {
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if (numbers[i] === numbers[a] + numbers[b]) continue number_loop;
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}
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}
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return [i, numbers[i]];
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}
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return [NaN, NaN];
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}
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/**
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* Main function for Puzzle B
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*
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* @param {string} data - Puzzle input as a single string.
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* @returns {number} The sum of the smallest and largest number in a contiguous range that adds up to the result of part A.
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*/
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async function main(data) {
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const numbers = data.split(/\r?\n/).map((line) => parseInt(line));
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const [, partAResult] = await partA(numbers);
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let minIndex = 0;
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let maxIndex = 1;
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while (
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numbers
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.slice(minIndex, maxIndex + 1)
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.reduce((prev, cur) => prev + cur, 0) !== partAResult
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) {
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maxIndex++;
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if (maxIndex == numbers.length) {
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minIndex++;
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maxIndex = minIndex + 1;
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}
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}
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const minNumber = Math.min(...numbers.slice(minIndex, maxIndex + 1));
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const maxNumber = Math.max(...numbers.slice(minIndex, maxIndex + 1));
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return minNumber + maxNumber;
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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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