feat: add recursive bubble sort algorithm with doctests and type hints

Implement recursive Bubble Sort algorithm with doctests.

Author: vannu07

sorts/bubble_sort_recursive.py

@@ -0,0 +1,39 @@
+from typing import List
+
+
+def bubble_sort_recursive(arr: List[int]) -> List[int]:
+    """
+    Sorts a list of integers using the recursive Bubble Sort algorithm.
+
+    >>> bubble_sort_recursive([5, 1, 4, 2, 8])
+    [1, 2, 4, 5, 8]
+    >>> bubble_sort_recursive([])
+    []
+    >>> bubble_sort_recursive([1])
+    [1]
+    >>> bubble_sort_recursive([3, 3, 2, 1])
+    [1, 2, 3, 3]
+    >>> bubble_sort_recursive([-1, 5, 0, -2])
+    [-2, -1, 0, 5]
+    """
+    n = len(arr)
+    if n <= 1:
+        return arr
+
+    swapped = False
+    for i in range(n - 1):
+        if arr[i] > arr[i + 1]:
+            arr[i], arr[i + 1] = arr[i + 1], arr[i]
+            swapped = True
+
+    # Base case: if no elements were swapped, the array is sorted
+    if not swapped:
+        return arr
+
+    # Recursive call for the remaining unsorted part
+    return bubble_sort_recursive(arr[:-1]) + [arr[-1]]
+
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()