KeyPadCombination.java

package codingInterview.Recursion;

import java.util.ArrayList;

public class KeyPadCombination {

    static String ms[] = {".", "abc", "def", "ghl", "jkl", "mno", "pqr", "st", "uvwx", "yz"};

    public static void main(String s[]) {
        //System.out.println(getAStrQA("179"););
        getAStrQA("179", "");
        //System.out.println(Integer.parseInt("147".charAt(0)+""));
    }

    public static ArrayList<String> getAStr(String s) {
        if (s.length() == 0) {
            ArrayList<String> al = new ArrayList<String>();
            al.add("");
            return al;

        }
        char ch = s.charAt(0);
        String ros = s.substring(1);
        int i = ch - '0';
        ArrayList<String> rr = getAStr(ros);
        ArrayList<String> my = new ArrayList<String>();

        for (String ad : rr)
            for (char sch : ms[i].toCharArray()) {
                my.add(sch + ad);
            }


        return my;
    }

    public static void getAStrQA(String Ques, String ans) {//KBC
        if (Ques.length() == 0) {
            System.out.println(ans);
            return;

        }
        char ch = Ques.charAt(0);
        String ros = Ques.substring(1);
        int i = ch - '0';
        for (char chs : ms[i].toCharArray()) {
            //getAStrQA(ros, ans);
            getAStrQA(ros, chs + ans);
        }
        return;
    }

}