(UVA) Quirksome Squares - Solution 2

If you want to see another solution for this problem, click here.

As in the previous solution, I applied Brute Force to solve this problem, and I also used the approach about exact square numbers.

The difference here is that I am transforming all the possible square numbers in a String with N-digits. Then, using these strings, I check whether they are a Quirksome Square.


import java.io.*;
import java.util.*;

class Main  {
    public static void process() throws NumberFormatException, IOException {  
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
       
        String line = br.readLine();
        while (line != null) {
            int numDigits = Integer.parseInt(line);
           
            int div = 1;
            for (int i = 0; i < numDigits; i+=2) {
                div *= 10;
            }
           
            StringBuilder end = new StringBuilder();
            for (int i = 0; i < numDigits; i++) {
                end.append(9);
            }
            int size = Integer.parseInt(end.toString());
           
            ArrayList<String> numbers = new ArrayList<String>();
            for (int i = 0; i*i <= size; i++) {
                int iLenght = Integer.toString(i*i).length();
                StringBuilder sb = new StringBuilder();
                while (sb.toString().length() < (numDigits-iLenght)) {
                    sb.append(0);
                }
                sb.append(i*i);
                numbers.add(sb.toString());
            }
           
            ArrayList<String> quirksomeSquares = new ArrayList<String>();
            for (int i = 0; i < numbers.size(); i++) {
                String s1 = numbers.get(i).substring(0,numbers.get(i).length()/2);
                String s2 = numbers.get(i).substring(numbers.get(i).length()/2,numbers.get(i).length());
                int numI = Integer.parseInt(numbers.get(i));
                int sumPow = (Integer.parseInt(s1)+Integer.parseInt(s2))*(Integer.parseInt(s1)+Integer.parseInt(s2));
                if (numI == sumPow) {
                    quirksomeSquares.add(numbers.get(i));
                }
            }
           
            for (int i = 0; i < quirksomeSquares.size(); i++) {
                System.out.println(quirksomeSquares.get(i));
            }
           
            line = br.readLine();
        }
                       
        return;
    }
  
    public static void main(String[] args) throws NumberFormatException, IOException {
        Main m = new Main();
        m.process();

        System.exit(0);
    }
}