Given an array of distinct integers numbers, your task is to find the number of pairs of indices (i, j) such that i ≤ j and the sum numbers[i] + numbers[j] is a full square.

Return the number of pairs you found.

Example:
[0, -1, 3, 1]
(0, 0), (-1, 1), (3, 1)

Therefore, Answer is 3.

I know it might not hard, but looking for optimal solution

Thanks