Sum of Square Numbers

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

 

Example 1:

Input: c = 5
Output: true
Explanation: 1 * 1 + 2 * 2 = 5

Example 2:

Input: c = 3
Output: false

Solution(Java):

class Solution {
    public boolean judgeSquareSum(int c) {
        int left=0, right=(int)Math.sqrt(c);
        while(left<=right){
            if(left*left+right*right==c)
                return true;
            else if(left*left+right*right<c)
                left++;
            else 
                right--;
        }
        return false;
    }
}