advent_of_code_2023/Day15/ts/solution.ts
2023-12-15 20:14:58 +01:00

81 lines
2.5 KiB
TypeScript

import * as fs from 'fs';
import * as path from 'path';
function hashLabel(label: string): number {
// Compute hash value for a given label
return [...label].reduce((value, char) => (value + char.charCodeAt(0)) * 17 % 256, 0);
}
function processSteps(steps: string[]): number {
const boxes: string[][] = Array.from({ length: 256 }, () => []);
const focalLengths: Map<string, number> = new Map();
steps.forEach(step => {
const match = step.match(/([a-z]+)([=-])(\d)?/);
if (!match) return;
const [, label, operation, focalLength] = match;
const hashed = hashLabel(label);
const destination = boxes[hashed];
console.log(`Processing step: ${label}${operation}${focalLength}, Box: ${hashed}`);
if (operation === "=") {
if (!destination.includes(label)) {
destination.push(label);
}
focalLengths.set(label, parseInt(focalLength));
} else {
const index = destination.indexOf(label);
if (index !== -1) {
destination.splice(index, 1);
}
focalLengths.delete(label);
}
});
return boxes.reduce((totalPower, box, boxNumber) =>
totalPower + box.reduce((boxPower, label, i) =>
boxPower + (boxNumber + 1) * (i + 1) * (focalLengths.get(label) || 0), 0), 0);
}
function readFileContent(filePath: string): string {
try {
return fs.readFileSync(filePath, 'utf-8');
} catch (error) {
console.error(`Error reading file at ${filePath}:`, (error as Error).message);
process.exit(1);
}
}
function testAlgorithm(): void {
const testContent = readFileContent(path.join(__dirname, '../test.txt'));
const testSteps = testContent.replace(/\n/g, '').split(',');
const testResult = processSteps(testSteps);
console.log(`Test Result: ${testResult}`);
if (testResult !== 145) {
console.error(`Test failed. Expected result is 145, got ${testResult}.`);
process.exit(1);
} else {
console.log('Test passed.');
}
}
function main(): void {
try {
testAlgorithm();
const inputContent = readFileContent(path.join(__dirname, '../input.txt'));
const inputSteps = inputContent.replace(/\n/g, '').split(',');
const finalResult = processSteps(inputSteps);
console.log(`Final Result: ${finalResult}`);
} catch (error) {
console.error(`An error occurred in main: ${(error as Error).message}`);
process.exit(1);
}
}
main();