Given an array a of N distinct numbers, write a function to count the number of ordered pairs of indices i,j such that ij, 0i

For example:

a[] ={1,2,6,3,4,5}

Output= 2.

Explanation: min(a)=1 and max(a)=6

2+5 = min(a)+max(a) and 3+4 = min(a)+max(a)

Note: You can define other helper functions upon need.