String Enumeration

//Discussion see:
//https://cs.stackexchange.com/questions/29841/enumerate-all-possible-strings-over-alphabet/

import java.util.*;

public class Test {
    public static void main(String[] args) {
        String[] alpha = {"a", "b", "c"};
        int i = alpha.length;
        while(i < 30) {
            Integer[] rep = getAryRep(i, alpha.length);
            if(rep[0] == 1) {
                i++;
            } else {
                i += alpha.length;
                continue;
            }
            StringBuilder b = new StringBuilder();
            for(int j = 1; j < rep.length; j++)
                b.append(alpha[rep[j]]);

            for(int j = 0; j <= b.length(); j++)
                System.out.printf("<%s, %s>%n", b.substring(0, j), b.substring(j));

            System.out.println();
        }
    }
    public static Integer[] getAryRep(int nr, int ary) {
        ArrayList<Integer> res = new ArrayList<>();
        while(nr >= ary) {
            res.add(nr % ary);
            nr /= ary;
        }
        res.add(nr % ary);
        Collections.reverse(res);
        return (Integer[]) res.toArray(new Integer[res.size()]);
    }
}