Even and Odd

Easy

Given an array arr[] of size N containing equal number of odd and even numbers. Arrange the numbers in such a way that all the even numbers get the even index and odd numbers get the odd index.
Note: There are multiple possible solutions, Print any one of them. Also, 0-based indexing is considered.

 

Example 1:

Input:
N = 6
arr[] = {3, 6, 12, 1, 5, 8}
Output:
1
Explanation:
6 3 12 1 8 5 is a possible solution.
The output will always be 1 if your
rearrangement is correct.

Example 2:

Input:
N = 4
arr[] = {1, 2, 3, 4}
Output :
1

Your Task:  
You don't need to read input or print anything. Your task is to complete the function reArrange() which takes an integer N and an array arr of size N as input and reArranges the array in Place without any extra space.

Expected Time Complexity: O(N)
Expected Auxiliary Space: O(1)

Constraints:
1 ≤ N ≤ 10⁵
1 ≤ arr[i] ≤ 10⁵