🚀 benchmark ?

packages/compute/getAvailableRoutes2.ts

@@ -0,0 +1,65 @@
+import { Grid, isInsideLarge, getColor, isInside, isEmpty } from "./grid";
+import { around4 } from "./point";
+import {
+  getHeadX,
+  getHeadY,
+  nextSnake,
+  Snake,
+  snakeEquals,
+  snakeWillSelfCollide,
+} from "./snake";
+
+const snakeEqualsN = (a: Snake, b: Snake, n = a.length / 2) => {
+  for (let i = 0; i < n * 2; i++) if (a[i] !== b[i]) return false;
+  return true;
+};
+
+export const getAvailableRoutes = (grid: Grid, snake0: Snake, n?: number) => {
+  const openList: Snake[][] = [[snake0]];
+  const closeList: Snake[] = [];
+
+  const solutions: Snake[][] = [];
+
+  while (openList.length) {
+    const c = openList.shift()!;
+    const [snake] = c;
+
+    closeList.push(snake);
+
+    const cx = getHeadX(snake);
+    const cy = getHeadY(snake);
+
+    for (let i = 0; i < around4.length; i++) {
+      const { x: dx, y: dy } = around4[i];
+
+      const nx = cx + dx;
+      const ny = cy + dy;
+
+      if (
+        isInsideLarge(grid, 1, nx, ny) &&
+        !snakeWillSelfCollide(snake, dx, dy)
+      ) {
+        const nsnake = nextSnake(snake, dx, dy);
+
+        if (!closeList.some((s) => snakeEquals(nsnake, s))) {
+          const color = isInside(grid, nx, ny) && getColor(grid, nx, ny);
+
+          if (color && !isEmpty(color)) {
+            if (solutions.every(([s]) => !snakeEqualsN(s, nsnake, n))) {
+              const solution = [nsnake, ...c.slice(0, -1)];
+              solutions.push(solution);
+            }
+          } else {
+            if (!openList.some(([s]) => snakeEquals(nsnake, s))) {
+              const chain = [nsnake, ...c];
+              openList.push(chain);
+              openList.sort((a, b) => a.length - b.length);
+            }
+          }
+        }
+      }
+    }
+  }
+
+  return solutions;
+};