feat: add sleepsort algorithm

Author: Sebastian-GOAT

sorts/sleep_sort.ts

@@ -0,0 +1,43 @@
+/**
+ * @function sleepSort
+ * @description For each n, sleep sort waits n milliseconds before pushing it to the result array.
+ * @Complexity_Analysis
+ * Space complexity - O(n)
+ *                    Each element requires its own thread or timer instance,
+ *                    which scales linearly with the size of the input array.
+ *
+ * Time complexity
+ *      Best case   -   O(n + max(input))
+ *                      Occurs when the OS schedules threads in linear time and
+ *                      the maximum value in the input array is very small.
+ *
+ *      Worst case  -   unbounded
+ *                      Occurs when at least one of the numbers is infinitely or
+ *                      exponentially large, or when the system runs out of resources.
+ *
+ *      Average case -  O(n log n + max(input))
+ *                      Occurs as the OS scheduler inserts the n wake-up timers into
+ *                      an internal priority queue (min-heap), followed by the time
+ *                      it takes for the maximum element to finish sleeping.
+ *
+ * @param {number[]} arr - The input array.
+ * @return {number[]} - The sorted array.
+ * @example sleepSort([8, 3, 5, 1, 4, 2]) = [1, 2, 3, 4, 5, 8]
+ */
+export async function sleepSort(arr: number[], scale = 10): Promise<number[]> {
+
+  if (arr.length < 2) return arr
+
+  const result: number[] = []
+
+  const promises = arr.map(async num => {
+    return new Promise<void>(resolve => setTimeout(() => {
+      result.push(num)
+      resolve()
+    }, num * scale)) // Multiply the number by some scaling variable so the order stays correct
+  })
+
+  await Promise.all(promises)
+
+  return result
+}

sorts/test/sleep_sort.test.ts

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+import { sleepSort } from '../sleep_sort';
+
+describe('SleepSort', () => {
+  test.each([
+    { arr: [1], expectedResult: [1] },
+    { arr: [2, 1], expectedResult: [1, 2] },
+    { arr: [3, 1, 2], expectedResult: [1, 2, 3] },
+    { arr: [3, 4, 1, 2], expectedResult: [1, 2, 3, 4] }
+  ])(
+    'The return value of $arr should be $expectedResult',
+    async ({ arr, expectedResult }) => {
+      expect(await sleepSort(arr)).toStrictEqual(expectedResult);
+    }
+  );
+});