60 lines
1.3 KiB
JavaScript
60 lines
1.3 KiB
JavaScript
import * as R from "remeda";
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import Victor from "@a-robu/victor";
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import { readFile } from "../05/part1.js";
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import { passthru } from "../08/part1.js";
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const directions = {
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R: new Victor(1, 0),
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L: new Victor(-1, 0),
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U: new Victor(0, 1),
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D: new Victor(0, -1),
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};
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const parseLine = R.createPipe(
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(line) => line.split(" "),
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([direction, times]) => Array(parseInt(times)).fill(directions[direction])
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);
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export const readInput = (...args) =>
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R.pipe(
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readFile(...args),
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(text) => text.split("\n"),
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R.compact,
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R.map(parseLine),
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R.flatten
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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 touching = (v1, v2) =>
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[v1.distanceX(v2), v1.distanceY(v2)].every((x) => x * x <= 1);
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export const moveOnce = (head, tail) => (d) => {
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head.add(d);
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if (touching(head, tail)) return tail.toString();
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const delta = head.clone().subtract(tail).normalize();
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if (delta.x * delta.y) {
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delta.x = delta.x > 0 ? 1 : -1;
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delta.y = delta.y > 0 ? 1 : -1;
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}
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tail.add(delta);
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return tail.toString();
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};
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const moveAround = (directives) => {
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const head = new Victor(0, 0);
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const tail = new Victor(0, 0);
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const move = moveOnce(head, tail);
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return directives.map(move);
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};
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export default R.createPipe(moveAround, R.uniq, (moves) => moves.length);
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