Sum of Two Squares in Two Ways

Given a non-negative integer c, determine whether there exist two integers a and b such that a² + b² = c. In other words, check if the given number c can be expressed as the sum of two perfect squares. The integers a and b can be any non-negative integers, including zero. For example, c = 5 returns true because 1² + 2² = 5, whereas c = 3 returns false because no such integers exist.