Solution.java

// github.com/RodneyShag

import java.util.Scanner;

// Brute-force solution
public class Solution {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int p = scan.nextInt();
        int q = scan.nextInt();
        scan.close();
        
        boolean foundKaprekar = false;
        for (int num = p; num <= q; num++) {
            if (isKaprekar(num)) {
                foundKaprekar = true;
            }
        }
        if (!foundKaprekar) {
            System.out.println("INVALID RANGE");
        }
    }
    
    private static boolean isKaprekar(int num) {
        long squared = (long) num * num; // multiplying 2 ints without typecast could cause overflow
        String str   = String.valueOf(squared);
        String left  = str.substring(0, str.length() / 2);
        String right = str.substring(str.length() / 2);
        int numL = (left.isEmpty())  ? 0 : Integer.parseInt(left);
        int numR = (right.isEmpty()) ? 0 : Integer.parseInt(right);
        if (numL + numR == num) {
            System.out.print(num + " ");
            return true;
        } else {
            return false;
        }
    }
}