Add to List 633. Sum of Square Numbers（LeetCode）

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

Example 1:

Input: 5
Output: True
Explanation: 1 * 1 + 2 * 2 = 5

 

Example 2:

Input: 3
Output: False

class Solution {
public:
    bool judgeSquareSum(int c) {
      int i = 0;
        int j =sqrt(c);
        while (i <= j)
        {
            if (i*i + j*j == c)
                return true;
            else
            if (i*i + j*j < c)
            {
                i++;
            }
            else
                j--;
        }
        return false;
    }
};