Given a non-negative integer c, decide whether there're two integers a and b such that a2 + b2 = c.

Sure, here is a step-by-step guide to solve this problem:

1. Initialize two pointers, one at 0 (let's call it a) and another at the square root of c (let's call it b).

2. Create a while loop where a is less than or equal to b.

3. Inside the loop, calculate the sum of the squares of a and b.

4. If the sum is equal to c, then return True because we have found two numbers.

5. If the sum is less than c, increment a by 1 because we need a larger number to reach c.

6. If the sum is greater than c, decrement b by 1 because we need a smaller number to reach c.

7. If the loop finishes without finding two numbers, return False.

This algorithm works because it systematically checks all possible pairs of a and b that could sum to c. The use of two pointers allows us to efficiently narrow down the possibilities.