odd_even_sort.py (#4199)

* odd_even_sort.py

* Update odd_even_sort.py

* Update odd_even_sort.py

sorts/odd_even_sort.py

@@ -0,0 +1,47 @@
+"""For reference
+https://en.wikipedia.org/wiki/Odd%E2%80%93even_sort
+"""
+
+
+def odd_even_sort(input_list: list) -> list:
+    """this algorithm uses the same idea of bubblesort,
+    but by first dividing in two phase (odd and even).
+    Originally developed for use on parallel processors
+    with local interconnections.
+    :param collection: mutable ordered sequence of elements
+    :return: same collection in ascending order
+    Examples:
+    >>> odd_even_sort([5 , 4 ,3 ,2 ,1])
+    [1, 2, 3, 4, 5]
+    >>> odd_even_sort([])
+    []
+    >>> odd_even_sort([-10 ,-1 ,10 ,2])
+    [-10, -1, 2, 10]
+    >>> odd_even_sort([1 ,2 ,3 ,4])
+    [1, 2, 3, 4]
+    """
+    sorted = False
+    while sorted is False:  # Until all the indices are traversed keep looping
+        sorted = True
+        for i in range(0, len(input_list) - 1, 2):  # iterating over all even indices
+            if input_list[i] > input_list[i + 1]:
+
+                input_list[i], input_list[i + 1] = input_list[i + 1], input_list[i]
+                # swapping if elements not in order
+                sorted = False
+
+        for i in range(1, len(input_list) - 1, 2):  # iterating over all odd indices
+            if input_list[i] > input_list[i + 1]:
+                input_list[i], input_list[i + 1] = input_list[i + 1], input_list[i]
+                # swapping if elements not in order
+                sorted = False
+    return input_list
+
+
+if __name__ == "__main__":
+    print("Enter list to be sorted")
+    input_list = [int(x) for x in input().split()]
+    # inputing elements of the list in one line
+    sorted_list = odd_even_sort(input_list)
+    print("The sorted list is")
+    print(sorted_list)