Given an array of 0s and 1s. Find the length of the largest subarray with equal number of 0s and 1s.

Example 1:

Input:
N = 4
A[] = {0,1,0,1}
Output: 4
Explanation: The array from index [0...3]
contains equal number of 0's and 1's.
Thus maximum length of subarray having
equal number of 0's and 1's is 4.

Example 2:

Input:
N = 5
A[] = {0,0,1,0,0}
Output: 2

Your Task:
You don't need to read input or print anything. Your task is to complete the function maxLen() which takes the array arr[] and the size of the array as inputs and returns the length of the largest subarray with equal number of 0s and 1s.

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