:roclet: improve algorithm, add an intermediate phase to clean up residual cell from previous layer, before grabing the free ones

packages/demo/demo.getBestRoundTrip.ts

@@ -0,0 +1,54 @@
+import "./menu";
+import { createCanvas } from "./canvas";
+import { getSnakeLength } from "@snk/types/snake";
+import { grid, snake } from "./sample";
+import { getColor } from "@snk/types/grid";
+import { getBestTunnel } from "@snk/compute/getBestTunnel";
+import type { Color } from "@snk/types/grid";
+import type { Point } from "@snk/types/point";
+
+const { canvas, ctx, draw, highlightCell } = createCanvas(grid);
+document.body.appendChild(canvas);
+
+const ones: Point[] = [];
+
+for (let x = 0; x < grid.width; x++)
+  for (let y = 0; y < grid.height; y++)
+    if (getColor(grid, x, y) === 1) ones.push({ x, y });
+
+const points = getBestTunnel(
+  grid,
+  ones[0].x,
+  ones[0].y,
+  3 as Color,
+  getSnakeLength(snake)
+);
+
+let k = 0;
+
+const onChange = () => {
+  ctx.clearRect(0, 0, 9999, 9999);
+
+  draw(grid, [] as any, []);
+
+  if (points) {
+    points.forEach(({ x, y }) => highlightCell(x, y));
+    highlightCell(points[k].x, points[k].y, "blue");
+  }
+};
+
+onChange();
+
+const inputK = document.createElement("input") as any;
+inputK.type = "range";
+inputK.value = 0;
+inputK.step = 1;
+inputK.min = 0;
+inputK.max = points ? points.length - 1 : 0;
+inputK.style.width = "90%";
+inputK.style.padding = "20px 0";
+inputK.addEventListener("input", () => {
+  k = +inputK.value;
+  onChange();
+});
+document.body.append(inputK);