Files
aoc/2024/08/index.ts
T
2024-12-08 19:48:41 +01:00

82 lines
2.2 KiB
TypeScript

import { combinations, unique } from '../../utils/array.ts';
import { inBounds, isCoordinateEqual } from '../../utils/coordinates.ts';
export function solveFirst(input: string): number {
const rows = input.split('\n');
const antennas = new Map<string, [number, number][]>();
for (let y = 0; y < rows.length; y++) {
for (let x = 0; x < rows[y].length; x++) {
const digit = rows[y][x];
if (digit === '.') {
continue;
}
const entry = antennas.get(digit) || [];
entry.push([x, y]);
antennas.set(digit, entry);
}
}
const antiNodes: [number, number][] = [];
// console.log(rows);
// console.log(antennas);
antennas.forEach((positions) => {
combinations(positions).forEach(({ a, b }) =>
antiNodes.push([a[0] - (b[0] - a[0]), a[1] - (b[1] - a[1])])
);
});
const validAntiNodes = antiNodes
.filter(inBounds(rows[0].length, rows.length))
.filter(unique(isCoordinateEqual));
// validAntiNodes.forEach(([x, y]) => rows[y][x] === '.' && replaceChar(rows, x, y, '#'));
//
// console.log(rows.join('\n'));
return validAntiNodes.length;
}
export function solveSecond(input: string): number {
const rows = input.split('\n');
const antennas = new Map<string, [number, number][]>();
const yMax = rows.length;
const xMax = rows[0].length;
for (let y = 0; y < yMax; y++) {
for (let x = 0; x < xMax; x++) {
const digit = rows[y][x];
if (digit === '.') {
continue;
}
const entry = antennas.get(digit) || [];
entry.push([x, y]);
antennas.set(digit, entry);
}
}
const antiNodes: [number, number][] = [];
antennas.forEach((positions) => {
combinations(positions).forEach(({ a, b }) => {
for (let y = 0; y < yMax; y++) {
antiNodes.push([a[0] + (b[0] - a[0]) * y, a[1] + (b[1] - a[1]) * y]);
}
});
});
const validAntiNodes = antiNodes
.filter(inBounds(rows[0].length, rows.length))
.filter(unique(isCoordinateEqual));
// console.log(validAntiNodes);
// validAntiNodes.forEach(
// ([x, y]) => rows[y][x] === '.' && replaceChar(rows, x, y, '#')
// );
//
// console.log(rows.join('\n'));
return validAntiNodes.length;
}