633. Sum of Square Numbers

题目：

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: 5Output: TrueExplanation: 1 * 1 + 2 * 2 = 5

Example 2:

Input: 3Output: False

思路：

本题思路是真的简单，只需要循环遍历0-sqrt(c)的整数，判断是否存在符合要求的两个整数。

代码：

class Solution {public:    bool judgeSquareSum(int c) {        for(int a=0;a<=sqrt(c);a++)        {            if(sqrt(c-a*a)-int(sqrt(c-a*a))==0.0)                return true;        }        return false;    }};