90 lines
1.9 KiB
JavaScript
90 lines
1.9 KiB
JavaScript
import * as R from "remeda";
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import { readFile } from "../05/part1.js";
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import Victor from "@a-robu/victor";
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const V = (...args) => new Victor(...args);
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const readInput = (...args) =>
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readFile(...args)
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.split("\n")
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.filter((x) => x)
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.map((l) => l.split("").map((x) => parseInt(x)));
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export const outOfBound = (size) => (pos) => {
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if (Math.min(pos.x, pos.y) < 0) return true;
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if (Math.max(pos.x, pos.y) >= size) return true;
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return false;
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};
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export function generateVisibilityGrid(forest) {
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const size = forest.length;
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const visibility = Array(size)
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.fill(null)
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.map(() => Array(size).fill(false));
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// top
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const positions = R.range(size)(0).map((x) => ({
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height: -1,
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position: V(x, -1),
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inc: V(0, 1),
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}));
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// bottom
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positions.push(
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...R.range(size)(0).map((x) => ({
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height: -1,
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position: V(x, size),
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inc: V(0, -1),
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}))
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);
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positions.push(
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...R.range(size)(0).map((x) => ({
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height: -1,
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position: V(-1, x),
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inc: V(1, 0),
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}))
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);
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positions.push(
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...R.range(size)(0).map((x) => ({
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height: -1,
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position: V(size, x),
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inc: V(-1, 0),
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}))
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);
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while (positions.length) {
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const pos = positions.shift();
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pos.position.add(pos.inc);
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if (outOfBound(size)(pos.position)) continue;
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if (forest[pos.position.x][pos.position.y] > pos.height) {
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visibility[pos.position.x][pos.position.y] = true;
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pos.height = forest[pos.position.x][pos.position.y];
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}
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positions.push(pos);
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}
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return visibility;
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}
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export const puzzleInput = readInput(import.meta.url, "input");
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export const sample = readInput(import.meta.url, "sample");
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export const passthru = (func) => (arg) => {
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func(arg);
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return arg;
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};
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export const printMap = passthru((forest) =>
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forest.forEach((line) => console.log(line.join(" ")))
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);
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export default R.createPipe(
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generateVisibilityGrid,
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R.flatten,
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R.countBy(R.identity)
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);
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