q.java

import java.util.ArrayList;

public class q {
    public static void main(String[] args) {
        ArrayList<String> a = new ArrayList<> ();
        boolean[]f = new boolean[3];
        alpha(new String []{"c " , "a" , "r"} , 0 , a, f);
    }

    private static void alpha(String[] s, int i, ArrayList<String> a , boolean [] f) {
        if(a.size () - 1== s.length - 1){
            System.out.println (a);
            return;
        }
        for (int j = 0; j <s.length ; j++) {
            if (f[j] == false) {
                f[j] = true;
                a.add (s[j]);
                alpha (s, i + 1, a, f);
                a.remove (a.size () - 1);
                f[j] = false;
            }


        }
    }
}