Added reverse_selection_sort

DIRECTORY.md

@@ -1260,6 +1260,7 @@
   * [Recursive Insertion Sort](sorts/recursive_insertion_sort.py)
   * [Recursive Mergesort Array](sorts/recursive_mergesort_array.py)
   * [Recursive Quick Sort](sorts/recursive_quick_sort.py)
+  * [Reverse Selection Sort](sorts/reverse_selection_sort.py)
   * [Selection Sort](sorts/selection_sort.py)
   * [Shell Sort](sorts/shell_sort.py)
   * [Shrink Shell Sort](sorts/shrink_shell_sort.py)

sorts/reverse_selection_sort.py

@@ -0,0 +1,43 @@
+"""
+A pure Python implementation of the Reverse Selection Sort algorithm.
+This algorithm progressively sorts the array by finding the largest
+element in each pass and placing it at the front.
+For doctests run following command:
+python3 -m doctest -v reverse_selection_sort.py
+For manual testing run:
+python3 reverse_selection_sort.py
+"""
+
+
+def reverse_selection_sort(collection: list) -> list:
+    """
+    A pure implementation of reverse selection sort algorithm in Python
+    :param collection: some mutable ordered collection with heterogeneous
+    comparable items inside
+    :return: the same collection sorted in descending order
+    Examples:
+    >>> reverse_selection_sort([45,23,11,89,54,1,3,36])
+    [89, 54, 45, 36, 23, 11, 3, 1]
+    >>> reverse_selection_sort([0,-89,32,5,46,8,11])
+    [46, 32, 11, 8, 5, 0, -89]
+    >>> reverse_selection_sort([34,-2,-1,98,-42])
+    [98, 34, -1, -2, -42]
+    """
+    n = len(collection)
+    for i in range(n - 1):
+        # Find the maximum element in the unsorted portion
+        max_idx = i
+        for j in range(i + 1, n):
+            if collection[j] > collection[max_idx]:
+                max_idx = j
+
+        # Swap the maximum element with the first element of the unsorted portion
+        collection[i], collection[max_idx] = collection[max_idx], collection[i]
+
+    return collection
+
+
+if __name__ == "__main__":
+    user_input = input("Enter numbers separated by a comma:\n").strip()
+    unsorted = [int(item) for item in user_input.split(",")]
+    print(reverse_selection_sort(unsorted))