meh

2022/12/part1.js

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+import * as R from "remeda";
+import Victor from "@a-robu/victor";
+
+import { readFile } from "../05/part1.js";
+
+const V = (x,y) => new Victor(x,y);
+
+const readInput = (...args) =>
+  R.pipe(
+    readFile(...args),
+    (lines) => lines.split("\n"),
+    R.compact, // remove last line
+    R.map((line) => line.split("").map( c => c ==='S' ? '`' : c === 'E' ? '{' : c ))
+  );
+
+export const puzzleInput = readInput(import.meta.url, "input");
+export const sample = readInput(import.meta.url, "sample");
+
+export const findStart = (topoMap) => {
+  let y;
+  let x = R.findIndex(topoMap, (row) => {
+    let z = row.indexOf("`");
+    if (z === -1) return false;
+    y = z;
+    return true;
+  });
+    return V(x,y);
+};
+
+const directions = [ [0,1], [0,-1],[1,0],[-1,0] ].map(
+    d => V(...d)
+);
+
+const outOfMap = (maxX,maxY) => (loc) => {
+    if( Math.min( loc.x, loc.y ) < 0 ) return true;
+    if( loc.x >= maxX  ) return true;
+    if( loc.y >= maxY  ) return true;
+    return false;
+}
+
+const isReachable = (topoMap,pos) => {
+    const baseline = topoMap[pos.x][pos.y].charCodeAt(0);
+
+    return (next) => {
+       return [0,1].includes(
+        topoMap[next.x][next.y].charCodeAt(0) - baseline
+    )
+    }
+}
+
+function findShortestPath(topoMap) {
+
+    const initial = findStart(topoMap);
+    initial.steps = 0;
+    initial.beenThere = [];
+
+    const potentials = [ initial ];
+
+    let bestSoFar;
+
+    const oom = outOfMap(topoMap.length,topoMap[0].length );
+
+    let failsafe = 100000;
+    while( potentials.length > 0 ) {
+       // if(! failsafe--) return;
+        const pos = potentials.pop(); // depth-first
+        //console.log(pos.steps, bestSoFar);
+
+        if( bestSoFar && (bestSoFar <= pos.steps) ) continue;
+
+        if( topoMap[pos.x][pos.y] === '{' ) {
+            bestSoFar = pos.steps;
+            continue;
+        }
+
+        const next = directions.map(
+            d => d.clone().add(pos)
+        ).filter( R.isNot(oom ))
+         .filter( isReachable(topoMap,pos) )
+        .filter( next => !pos.beenThere.includes( next.toArray().join(',') ) );
+
+        next.forEach( n => n.steps = pos.steps + 1 );
+        next.forEach( n => n.beenThere = [
+            ...pos.beenThere, pos.toArray().join(',')
+        ] );
+
+        potentials.push(...next);
+    }
+
+    return bestSoFar;
+
+}
+
+export default findShortestPath;

2022/12/part2.js

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+import * as R from "remeda";
+
+
+export default () => {};

2022/12/sample

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+Sabqponm
+abcryxxl
+accszExk
+acctuvwj
+abdefghi

2022/12/test.js

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+import { test, expect, describe } from "vitest";
+
+import { expectSolution } from "../01/main.js";
+import part1, { findStart, sample, puzzleInput } from "./part1.js";
+import part2 from "./part2.js";
+
+describe("part 1", () => {
+    test( "findStart", () => {
+        expect( findStart(sample).toArray() ).toEqual(
+            [0,0]
+        )
+
+    });
+    test( "sample", async () => {
+        expect(part1(sample)).toEqual(31);
+    });
+  test.only("solution", () => {
+    expectSolution(part1(puzzleInput)).toEqual("TODO");
+  });
+});
+
+describe("part 2", () => {
+  test.todo("solution", () => {
+    expectSolution(part2(puzzleInput)).toEqual("TODO");
+  });
+});