feat: complete sleep sort implementation with tests and error handling

Author: vishrutha-rao-k

sorts/sleep_sort.py

@@ -1,37 +1,95 @@
+"""
+Sleep Sort Algorithm Implementation
+
+Sleep sort works by creating a separate thread for each element in the input array,
+where each thread sleeps for a duration proportional to the element's value.
+When the thread wakes up, the element is appended to the result list.
+Smaller values wake up first, resulting in a sorted list.
+"""
+
 import threading
 import time
 
+
 def sleep_sort(arr: list[int]) -> list[int]:
     """
-    Sleep sort implementation - each element sleeps for n seconds then gets appended
+    Sort list using sleep sort algorithm.
+
+    Args:
+        arr: List of non-negative integers
+
+    Returns:
+        Sorted list in ascending order
+
+    Examples:
+        >>> sleep_sort([3, 1, 4, 2])
+        [1, 2, 3, 4]
+        >>> sleep_sort([])
+        []
+        >>> sleep_sort([5])
+        [5]
     """
     if not arr:
         return []
-    
-    result = []
-    
-    def add_to_result(n):
-        time.sleep(n)
-        result.append(n)
-    
+
+    result: list[int] = []
+    lock = threading.Lock()
+
+    def add_to_result(value: int) -> None:
+        time.sleep(value)
+        with lock:
+            result.append(value)
+
     threads = []
     for num in arr:
+        if num < 0:
+            raise ValueError("Sleep sort only works with non-negative integers")
         thread = threading.Thread(target=add_to_result, args=(num,))
         thread.start()
         threads.append(thread)
-    
+
     for thread in threads:
         thread.join()
-    
+
     return result
 
-if __name__ == "__main__":
-    # Test the sleep sort
-    user_input = input("Enter numbers separated by commas: ")
-    if user_input:
-        numbers = [int(x) for x in user_input.split(",")]
-        print("Original:", numbers)
-        sorted_numbers = sleep_sort(numbers)
-        print("Sorted:", sorted_numbers)
-    else:
-        print("No input provided")
+
+def test_sleep_sort() -> None:
+    """Test sleep sort algorithm with various test cases."""
+    # Test basic functionality
+    assert sleep_sort([3, 1, 4, 2]) == [1, 2, 3, 4]
+    
+    # Test edge cases
+    assert sleep_sort([]) == []
+    assert sleep_sort([5]) == [5]
+    assert sleep_sort([1, 1, 1]) == [1, 1, 1]
+    assert sleep_sort([1, 2, 3, 4, 5]) == [1, 2, 3, 4, 5]
+    assert sleep_sort([5, 4, 3, 2, 1]) == [1, 2, 3, 4, 5]
+    
+    print("All tests passed!")
+
+
+if __name__ == "_main_":
+    # Run automated tests
+    test_sleep_sort()
+    
+    # Interactive demo
+    try:
+        user_input = input("Enter non-negative numbers separated by commas: ").strip()
+        if user_input:
+            numbers = [int(x.strip()) for x in user_input.split(",")]
+            print(f"Original list: {numbers}")
+            
+            # Validate input
+            if any(num < 0 for num in numbers):
+                print("Error: Sleep sort only works with non-negative integers")
+            else:
+                print("Sorting... (this will take time proportional to the largest number)")
+                sorted_numbers = sleep_sort(numbers)
+                print(f"Sorted list: {sorted_numbers}")
+        else:
+            print("No input provided.")
+    except ValueError:
+        print("Error: Please enter valid integers separated by commas.")
+    except KeyboardInterrupt:
+        print("\nProgram interrupted by user.")