633 - Sum of Square Numbers

 JAVA

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

C++

class Solution {
public:
    bool judgeSquareSum(int c) {
        long a = 0, b = (long) sqrt(c);
        while (a <= b) {
            long s = a * a + b * b;
            if (s == c) return true;
            if (s < c)
                ++a;
            else
                --b;
        }
        return false;
    }
}