This commit is contained in:
Yanick Champoux 2022-12-08 16:19:44 -05:00
parent 8959352c9b
commit 6bcdb14d26
3 changed files with 66 additions and 16 deletions

View File

@ -10,6 +10,12 @@ const readInput = (...args) =>
.filter((x) => x)
.map((l) => l.split("").map((x) => parseInt(x)));
export const outOfBound = (size) => (pos) => {
if (Math.min(pos.x, pos.y) < 0) return true;
if (Math.max(pos.x, pos.y) >= size) return true;
return false;
};
export function generateVisibilityGrid(forest) {
const size = forest.length;
const visibility = Array(size)
@ -47,17 +53,11 @@ export function generateVisibilityGrid(forest) {
}))
);
const outOfBound = (pos) => {
if (Math.min(pos.x, pos.y) < 0) return true;
if (Math.max(pos.x, pos.y) >= size) return true;
return false;
};
while (positions.length) {
const pos = positions.shift();
pos.position.add(pos.inc);
if (outOfBound(pos.position)) continue;
if (outOfBound(size)(pos.position)) continue;
if (forest[pos.position.x][pos.position.y] > pos.height) {
visibility[pos.position.x][pos.position.y] = true;
@ -73,7 +73,7 @@ export function generateVisibilityGrid(forest) {
export const puzzleInput = readInput(import.meta.url, "input");
export const sample = readInput(import.meta.url, "sample");
function printMap(forest) {
export function printMap(forest) {
forest.forEach((line) => console.log(line.join(" ")));
return forest;
}

View File

@ -1,4 +1,50 @@
import * as R from "remeda";
import memo from "memoizerific";
import Victor from "@a-robu/victor";
import { printMap, outOfBound } from "./part1";
export default () => {};
const V = (...args) => new Victor(...args);
function visibility(forest, x, y, dx, dy) {
const pos = V(x, y);
const inc = V(dx, dy);
let vis = 0;
while (true) {
pos.add(inc);
if (outOfBound(forest.length)(pos)) return vis;
if (forest[x][y] <= forest[pos.x][pos.y]) return 1 + vis;
vis++;
}
}
const visibilityAround = (forest) => (x, y) => {
return [
[0, 1],
[0, -1],
[1, 0],
[-1, 0],
]
.map((d) => visibility(forest, x, y, ...d))
.reduce((a, b) => a * b);
};
export default R.createPipe(
(forest) => {
const viz = Array(forest.length)
.fill(null)
.map(() => Array(forest.length).fill(0));
for (const x of R.range(0, forest.length)) {
for (const y of R.range(0, forest.length)) {
viz[x][y] = visibilityAround(forest)(x, y);
}
}
return viz;
},
R.flatten,
R.maxBy(R.identity)
);

View File

@ -1,13 +1,12 @@
import { test, expect, describe } from "vitest";
import { expectSolution } from "../01/main.js";
import part1, { sample, puzzleInput, generateVisibilityGrid } from "./part1.js";
import part1, { sample, puzzleInput } from "./part1.js";
import part2 from "./part2.js";
describe("part 1", () => {
test( "sample", () => {
expect( part1(sample) ).toBe(21);
test("sample", () => {
expect(part1(sample)).toBe(21);
});
test("solution", () => {
expectSolution(part1(puzzleInput)).toEqual(1703);
@ -15,7 +14,12 @@ describe("part 1", () => {
});
describe("part 2", () => {
test.todo("solution", () => {
expectSolution(part2(puzzleInput)).toEqual("TODO");
test("sample", () => {
expect(part2(sample)).toBe(8);
});
test("solution", () => {
const solution = part2(puzzleInput);
expect(solution).toBeGreaterThan(160);
expectSolution(solution).toEqual(496650);
});
});