An Odd-Even Sort or brick sort is a simple sorting algorithm, which is developed for use on parallel processors with

local interconnection. It works by comparing all odd/even indexed pairs of adjacent elements in the list and, if a pair

is in the wrong order the elements are switched.

The next step repeats this for even/odd indexed pairs. Then it alternates between odd/even and even/odd steps until the list is sorted.

Pseudo code for Odd-Even Sort:

if n>2 then 1. apply odd-even merge(n/2) recursively to the even subsequence a0, a2, ..., an-2 and to the odd subsequence a1, a3, , ..., an-1 2. comparison [i : i+1] for all i element {1, 3, 5, 7, ..., n-3} else comparison [0 : 1]

Wikipedia has best illustration of Odd-Even sort:

Example of Odd-Even Sort:

**Implementation:**

I used C# language to implement Odd-Even Sort Algorithm.

public class OddEvenSort { private static void SortOddEven(int[] input, int n) { var sort = false; while (!sort) { sort = true; for (var i = 1; i < n - 1; i += 2) { if (input[i] <= input[i + 1]) continue; var temp = input[i]; input[i] = input[i + 1]; input[i + 1] = temp; sort = false; } for (var i = 0; i < n - 1; i += 2) { if (input[i] <= input[i + 1]) continue; var temp = input[i]; input[i] = input[i + 1]; input[i + 1] = temp; sort = false; } } } public static int[] Main(int[] input) { SortOddEven(input, input.Length); return input; } }

Auxiliary Space: O(n)

Time Complexity: O(n)