71 lines
1.5 KiB
JavaScript
71 lines
1.5 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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const readInput = (...args) => 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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const touching = (v1,v2) => [v1.distanceX(v2), v1.distanceY(v2)].every(
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x => x*x <= 1
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);
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export function moveOnce( head, tail, d ) {
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head.add(d);
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if( touching(head,tail) ) return;
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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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}
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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 visited = [ tail.toString() ]
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for ( const d of directives ) {
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moveOnce(head,tail,d);
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visited.push( tail.toString() );
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}
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return visited;
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};
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export default R.createPipe(
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moveAround,
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passthru( x => console.log(x) ),
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R.uniq,
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R.countBy( R.identity )
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);
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