Given an array A[] of N positive integers. The task is to find the maximum of j - i subjected to the constraint of A[i] <= A[j].
 

Example 1:

Input:
N = 2
A[] = {1, 10}
Output:
1
Explanation:
A[0]<=A[1] so (j-i) is 1-0 = 1.

Example 2:

Input:
N = 9
A[] = {34, 8, 10, 3, 2, 80, 30, 33, 1}
Output:
6
Explanation:
In the given array A[1] < A[7]
satisfying the required 
condition(A[i] <= A[j]) thus giving 
the maximum difference of j - i 
which is 6(7-1).

Your Task:
The task is to complete the function maxIndexDiff() which finds and returns maximum index difference. Printing the output will be handled by driver code.

Constraints:
1 ≤ N ≤ 10⁷
0 ≤ A[i] ≤ 10¹⁸

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