Java permutation function returns zero for some reason…? [closed]

The following code works in Python but seems to return zero in Java for some reason. Can you point out any errors?

import java.util.ArrayList;
import javax.swing.JOptionPane;

public class Test {
    public static void main(String[] args) {
        boolean run = true;
        String s = null;
        while (run){
            s = JOptionPane.showInputDialog(null, "Enter a string [quit to exit]: ");
            if (s.equalsIgnoreCase("quit")){
                run = false;
            }
            try{
                JOptionPane.showMessageDialog(null, "The string you entered can make " + permute(s) + " more words", "SUCCESS!", JOptionPane.INFORMATION_MESSAGE);
            }
            catch (Exception e){
                System.out.println("possible division by zero happened");
            }

        }
    }
    /*Newbie function for finding out the occurrence of a char in a string
    works good for the task at hand */
    public static int count(char CHAR, String s){
        int counter = 0;
        for (int i = 0 ; i < s.length() ; i++){
            if (s.charAt(i) == CHAR )
                counter++;

        }
        return counter;
    }

    //The actual permute function, takes a string
    public static final long permute(String s) throws Exception {
        ArrayList<Integer> pqr = new ArrayList<>();
        ArrayList<Character> checkList = new ArrayList<>();
        s = s.toLowerCase();
        int n = s.length();
        int c = 0;
        char character = 0;
        for (int i = 0 ; i < n ; i++){
            character = s.charAt(i);
            c = count( character, s );
            if (c>1 && !checkList.contains(character)){
                pqr.add(c);
                checkList.add(character);
            }
        }
        long r = 0;
        for (int j : pqr)
            r *= fact(j);
        return fact(n) / r;
    }
    //For finding out factorials
    public static long fact(int number){
        if (number <= 1){
            return 1;
        } else {
            return number * fact(number - 1);
        }
    }
}