Adjacent element arrangement in Circular Array

Given a circular array arr[] of size N where the last element is adjacent to the first element, the task is to arrange an array where the adjacent element's absolute difference is 1. Return "YES" Otherwise "NO".

Examples:

Input: N = 6, arr[] = {1, 1, 2, 2, 2, 3}
Output: YES
Explanation: {2, 1, 2, 1, 2, 3} is one of the possible rearrangements.

Approach: This can be solved with the following idea:

Check the parity of each element, and store them in different vectors. Check whether the absolute difference between even and odd elements is 1 or not.

Below are the steps involved:

• Initialize two vectors even and odd.
• Store even elements in even and odd in odd vectors.
• If the size of both vectors is different, Return "NO".
• Check for each odd [i] - even [i], the difference is one or not, for each i.
• Return "YES", if 1 for everyone.

Below is the implementation of the code:

YES

Time Complexity: O(N)
Auxilairy Space: O(N)