Create Conditional Triplet.cpp for a Leetcode problem #21

[phdtrong]

This is for the Opening issue#21 from repo, https://github.com/sastava007/Tech-Interview-Preparation/issues/21 the corresponding Leetcode problem link 1577 as showing below: https://leetcode.com/problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers/