Solution.java

//Problem: https://www.hackerrank.com/challenges/kaprekar-numbers
//Java 8
import java.io.*;
import java.util.*;

public class Solution {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner input = new Scanner(System.in);
        int p = input.nextInt();
        int q = input.nextInt();
        
        boolean flag = false;//Denotes if a Kaprekar number has been found
        
        if(p == 1)//Handle the one case where a 1 digit square is a Kaprekar
        {
            System.out.print(i+" ");
            flag = true;
        }
        
        
        for(long i = p; i <= q; i++)
        {
            long squareLong = i * i;
            String squareStr = String.valueOf(squareLong);
            
            if(squareStr.length() > 1)
            {
                long left = Long.parseLong(squareStr.substring(0,(int)Math.ceil(squareStr.length()/2)));
                long right = Long.parseLong(squareStr.substring((int)Math.ceil(squareStr.length()/2), squareStr.length()));
                if(left+right == i)
                {
                    System.out.print(i+" ");
                    flag = true;
                }
            }
        }
        if(!flag)
        {
            System.out.println("INVALID RANGE");
        }
    }
}