feat(day11): rotate the map

Author: coderbyheart

day11_test.ts

@@ -0,0 +1,51 @@
+import { assertEquals } from "https://deno.land/std@0.208.0/assert/assert_equals.ts";
+
+Deno.test("Day 11: Cosmic Expansion", async (t) => {
+  await t.step(
+    "rotate map",
+    async (t) => {
+      await t.step("rotateLeft()", () =>
+        assertEquals(
+          rotateLeft([
+            `123`,
+            `456`,
+          ]),
+          [
+            `36`,
+            `25`,
+            `14`,
+          ],
+        ));
+
+      await t.step("rotateRight()", () =>
+        assertEquals(
+          rotateRight([
+            `36`,
+            `25`,
+            `14`,
+          ]),
+          [
+            `123`,
+            `456`,
+          ],
+        ));
+    },
+  );
+});
+
+const rotateLeft = (map: Array<string>): Array<string> => {
+  const res: Array<Array<string>> = [];
+  const w = map[0].length;
+  for (let col = 0; col < w; col++) {
+    for (let row = 0; row < map.length; row++) {
+      const i = w - col - 1;
+      if (res[i] === undefined) res[i] = [];
+      res[i][row] = map[row][col];
+    }
+  }
+
+  return res.map((row) => row.join(""));
+};
+
+const rotateRight = (map: Array<string>): Array<string> =>
+  rotateLeft(rotateLeft(rotateLeft(map)));