88 lines
2.0 KiB
JavaScript
88 lines
2.0 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 function generateVisibilityGrid(forest) {
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const size = forest.length;
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const visibility = Array(size).fill(null).map(
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() => Array(size).fill(false)
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);
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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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const outOfBound = (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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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( 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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function printMap( forest ) {
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forest.forEach( line => console.log(line.join(' ')) );
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return forest;
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}
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export default R.createPipe(
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printMap,
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generateVisibilityGrid,
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printMap,
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R.flatten,
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R.countBy(R.identity)
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);
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