🚀 refactor algorithm

packages/compute/__tests__/benchmark.ts

@@ -1,29 +0,0 @@
-import { realistic as grid } from "@snk/types/__fixtures__/grid";
-import { snake3 } from "@snk/types/__fixtures__/snake";
-import { performance } from "perf_hooks";
-import { getAvailableRoutes } from "../getAvailableRoutes";
-import { getBestRoute } from "../getBestRoute";
-
-{
-  const m = 100;
-  const s = performance.now();
-  for (let k = m; k--; ) {
-    const solutions = [];
-
-    getAvailableRoutes(grid, snake3, (snakes) => {
-      solutions.push(snakes);
-      return false;
-    });
-  }
-  console.log("getAvailableRoutes", (performance.now() - s) / m, "ms");
-}
-
-{
-  const m = 10;
-  const s = performance.now();
-  for (let k = m; k--; ) {
-    getBestRoute(grid, snake3);
-  }
-
-  console.log("getBestRoute", (performance.now() - s) / m, "ms");
-}

packages/compute/__tests__/getBestRoute-fuzz.spec.ts

@@ -1,21 +1,25 @@
 import { getBestRoute } from "../getBestRoute";
-import { Color, createEmptyGrid } from "@snk/types/grid";
 import { snake3 } from "@snk/types/__fixtures__/snake";
-import { randomlyFillGrid } from "@snk/types/randomlyFillGrid";
-import ParkMiller from "park-miller";
+import {
+  getHeadX,
+  getHeadY,
+  Snake,
+  snakeWillSelfCollide,
+} from "@snk/types/snake";
+import { createFromSeed } from "@snk/types/__fixtures__/createFromSeed";
 
 const n = 1000;
 const width = 5;
 const height = 5;
 it(`should find solution for ${n} ${width}x${height} generated grids`, () => {
   const results = Array.from({ length: n }, (_, seed) => {
-    const grid = createEmptyGrid(width, height);
-    const pm = new ParkMiller(seed);
-    const random = pm.integerInRange.bind(pm);
-    randomlyFillGrid(grid, { colors: [1, 2] as Color[], emptyP: 2 }, random);
+    const grid = createFromSeed(seed, width, height);
 
     try {
-      getBestRoute(grid, snake3);
+      const chain = getBestRoute(grid, snake3);
+
+      assertValidPath(chain);
+
       return { seed };
     } catch (error) {
       return { seed, error };
@@ -24,3 +28,15 @@ it(`should find solution for ${n} ${width}x${height} generated grids`, () => {
 
   expect(results.filter((x) => x.error)).toEqual([]);
 });
+
+const assertValidPath = (chain: Snake[]) => {
+  for (let i = 0; i < chain.length - 1; i++) {
+    const dx = getHeadX(chain[i + 1]) - getHeadX(chain[i]);
+    const dy = getHeadY(chain[i + 1]) - getHeadY(chain[i]);
+
+    if (!((Math.abs(dx) === 1 && dy == 0) || (Math.abs(dy) === 1 && dx == 0)))
+      throw new Error(`unexpected direction ${dx},${dy}`);
+
+    if (snakeWillSelfCollide(chain[i], dx, dy)) throw new Error(`self collide`);
+  }
+};

packages/compute/__tests__/getBestRoute.spec.ts

@@ -15,7 +15,7 @@ it("should find best route", () => {
 
   const chain = getBestRoute(grid, createSnakeFromCells(snk0))!;
 
-  expect(snakeToCells(chain[0])[1]).toEqual({ x: 0, y: 0 });
+  expect(snakeToCells(chain[1])[1]).toEqual({ x: 0, y: 0 });
 
   expect(snakeToCells(chain[chain.length - 1])[0]).toEqual({ x: 3, y: 3 });
 });