NumberFun.java

/*
   Find the next perfect square!
   You might know some pretty large perfect squares. But what about the NEXT one?

    Complete the findNextSquare method that finds the next integral perfect square after the one passed as a parameter. Recall that an integral perfect square is an integer n such that sqrt(n) is also an integer.

    If the parameter is itself not a perfect square, than -1 should be returned. You may assume the parameter is positive.

    Examples:

    findNextSquare(121) --> returns 144
    findNextSquare(625) --> returns 676
    findNextSquare(114) --> returns -1 since 114 is not a perfect
 */

public class NumberFun {
    public static long findNextSquare(long sq) {
        double ans =  Math.sqrt(sq);
        long chk = (long) ans;
        chk = chk*chk;
        System.out.println(ans);
        if(chk==sq){
          long ret = (long) ans;
          ret++;
          ret = ret*ret;
          return ret;
        }
        else  return -1;
    }

    public static void main(String[]args) {
        System.out.println(findNextSquare(121));
    }
  }