adventofcode/2022/08/part2.js

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import * as R from "remeda";
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import Victor from "@a-robu/victor";
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import { outOfBound } from "./part1";
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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++;
}
}
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const visibilityAround = (forest) => (x, y) =>
[
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[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) => {
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const va = visibilityAround(forest);
return forest.map((l, x) => l.map((_, y) => va(x, y)));
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},
R.flatten,
R.maxBy(R.identity)
);