Python: Sort an odd–even sort or odd–even transposition sort

Last update on April 23 2025 12:50:03 (UTC/GMT +8 hours)

35. Odd-Even Sort

Write a Python program to sort an odd–even sort or odd–even transposition sort.

From Wikipedia:
In computing, an odd–even sort or odd–even transposition sort (also known as brick sort self-published source] or parity sort) is a relatively simple sorting algorithm, developed originally for use on parallel processors with local interconnections. It is a comparison sort related to bubble sort, with which it shares many characteristics. It functions by comparing all odd/even indexed pairs of adjacent elements in the list and, if a pair is in the wrong order (the first is larger than the second) the elements are switched. The next step repeats this for even/odd indexed pairs (of adjacent elements). Then it alternates between odd/even and even/odd steps until the list is sorted.

Sample Solution:

Python Code:

def odd_even_transposition(arr: list) -> list:
    arr_size = len(arr)
    for _ in range(arr_size):
        for i in range(_ % 2, arr_size - 1, 2):
            if arr[i + 1] < arr[i]:
                arr[i], arr[i + 1] = arr[i + 1], arr[i]

    return arr
            
nums = [4, 3, 5, 1, 2]
print("\nOriginal list:")
print(nums)
odd_even_transposition(nums)
print("Sorted order is:", nums)
nums = [5, 9, 10, 3, -4, 5, 178, 92, 46, -18, 0, 7]
print("\nOriginal list:")
print(nums)
odd_even_transposition(nums)
print("Sorted order is:", nums)

Sample Output:

Original list:
[4, 3, 5, 1, 2]
Sorted order is: [1, 2, 3, 4, 5]

Original list:
[5, 9, 10, 3, -4, 5, 178, 92, 46, -18, 0, 7]
Sorted order is: [-18, -4, 0, 3, 5, 5, 7, 9, 10, 46, 92, 178]

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to implement odd-even transposition sort on a list and verify that the list satisfies the wiggle property.
Write a Python script to perform odd-even sort on a list of integers and then count the number of iterations required.
Write a Python program to implement odd-even sort and print the list after each odd and even phase separately.
Write a Python function to sort a list using odd-even transposition sort and compare the result with bubble sort on the same list.

Go to:

Previous: Write a Python program to sort unsorted numbers using Patience sorting.
Next: Write a Python program to sort unsorted numbers using non-parallelized implementation of odd-even transposition sort.

Python Code Editor:

Contribute your code and comments through Disqus.