Sum of Square Numbers

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

    public boolean judgeSquareSum(int c) {
        int left = 0;
        for (int right = (int) Math.pow(2, 0.5) * (int) Math.pow(c, 0.5); right >= 0; right--) {
            while (right >= left) {
                int count = (int) (Math.pow(left, 2) + Math.pow(right, 2));
                if (count > c) {
                    break;
                } else if (count < c) {
                    left++;
                } else if (count == c) {
                    return true;
                }
            }
        }
        return false;
    }

第二种时间超时

    public boolean judgeSquareSum(int c) {
        for (int i = 0; i * i <= c; i++) {
            int left = c - i * i;
            int sqleft = (int) Math.pow(left, 0.5);
            if (sqleft * sqleft == left) {
                return true;
            }
        }
        return false;
    }