https://adventofcode.com/2024/day/5

import * as fs from 'fs';
import * as readline from 'readline';
import { performance } from 'perf_hooks';


function swap(array: number[], from: number, to: number): void {
    [array[from], array[to]] = [array[to], array[from]];
}

function rearrangeSequence(sortingPairs: number[][], sequence: number[], iterations: number = 0, maxIterations = 100): number {
    if (iterations > maxIterations) {
        console.error('Max iterations reached');
        return 0;
    }

    let swapped = false;
    for (let i = 0; i < sortingPairs.length; i++) {
        const [start, end] = sortingPairs[i];
        const startPos = sequence.indexOf(start);
        const endPos = sequence.indexOf(end);

        if (startPos > endPos) {
            swap(sequence, startPos, endPos);
            swapped = true;
        }
    }

    if (swapped) {
        iterations++;
        return rearrangeSequence(sortingPairs, sequence, iterations, maxIterations);
    }

    return iterations;
}

const rl = readline.createInterface({
  input: fs.createReadStream(__dirname + '/day5a_input.txt')
});

const sortingPairs: number[][] = [];
const sequences: number[][] = [];

rl.on('line', (line) => {
    if (line.indexOf('|') !== -1) {
        sortingPairs.push(line.split('|').map((pair) => +pair.trim()));
    } else if (line.trim() !== '') {
        sequences.push(line.split(',').map((order) => +order.trim()));
    }
});
rl.on('close', () => {
    let day1Answer = 0;
    let day2Answer = 0;
    let totalIterations = 0;
    let maxIterations = 0;

    const startTime = performance.now()

    sequences.forEach((sequence) => {
        // Get sorting pairs where both numbers exist in the sequence
        const matchingSortingPairs = sortingPairs.filter((pair) => sequence.indexOf(pair[0]) >= 0 && sequence.indexOf(pair[1]) >= 0);

        let iterations = rearrangeSequence(matchingSortingPairs, sequence, 0);
        if (iterations > 0) {
            day2Answer += sequence[Math.floor(sequence.length / 2)];
        } else {
            day1Answer += sequence[Math.floor(sequence.length / 2)];
        }
        totalIterations += iterations;
        maxIterations = Math.max(maxIterations, iterations);
    });
    console.log(day1Answer);
    console.log(day2Answer);
    console.log(maxIterations);
    const endTime = performance.now();
    console.log(`the solution took ${endTime - startTime} milliseconds`)
});