adventofcode/2022/08/part1.js

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2022-12-08 16:15:24 +00:00
import * as R from "remeda";
import { readFile } from "../05/part1.js";
import Victor from '@a-robu/victor';
const V = (...args) => new Victor(...args);
const readInput = (...args) =>
readFile(...args)
.split("\n")
.filter((x) => x)
.map( l => l.split('').map( x => parseInt(x) ) );
export function generateVisibilityGrid(forest) {
const size = forest.length;
const visibility = Array(size).fill(null).map(
() => Array(size).fill(false)
);
// top
const positions = R.range(size)(0).map( x => ({
height: -1,
position: V(x,-1),
inc: V(0,1),
}) );
// bottom
positions.push(
...R.range(size)(0).map( x => ({
height: -1,
position: V(x,size),
inc: V(0,-1),
}) )
);
positions.push(
...R.range(size)(0).map( x => ({
height: -1,
position: V(-1,x),
inc: V(1,0),
}) )
);
positions.push(
...R.range(size)(0).map( x => ({
height: -1,
position: V(size,x),
inc: V(-1,0),
}) )
);
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( forest[pos.position.x][pos.position.y] > pos.height ) {
visibility[pos.position.x][pos.position.y] = true;
pos.height = forest[pos.position.x][pos.position.y];
}
positions.push(pos);
}
return visibility;
}
export const puzzleInput = readInput(import.meta.url, "input");
export const sample = readInput(import.meta.url, "sample");
function printMap( forest ) {
forest.forEach( line => console.log(line.join(' ')) );
return forest;
}
export default R.createPipe(
printMap,
generateVisibilityGrid,
printMap,
R.flatten,
R.countBy(R.identity)
);