package Strings;
import java.util.*;

public class List_all_Possible_Words_From_Phone_Digits {
 
    static Character[][] numberToCharMap;
 
private static List<String> printWords(int[] numbers,
                                       int len,
                                       int numIndex,
                                       String s)
{
  if(len == numIndex)
  {
    return new ArrayList<>(Collections.singleton(s));
  }
   
  List<String> stringList = new ArrayList<>();
   
  for(int i = 0;
          i < numberToCharMap[numbers[numIndex]].length; i++)
  {
    String sCopy =
           String.copyValueOf(s.toCharArray());
    sCopy = sCopy.concat(
            numberToCharMap[numbers[numIndex]][i].toString());
    stringList.addAll(printWords(numbers, len,
                                 numIndex + 1,
                                 sCopy));
  }
  return stringList;
}
     
private static void printWords(int[] numbers)
{
  generateNumberToCharMap();
  List<String> stringList =
       printWords(numbers, numbers.length, 0, "");
  stringList.stream().forEach(System.out :: println);
}
 
private static void generateNumberToCharMap()
{
  numberToCharMap = new Character[10][5];
  numberToCharMap[0] = new Character[]{'\0'};
  numberToCharMap[1] = new Character[]{'\0'};
  numberToCharMap[2] = new Character[]{'a','b','c'};
  numberToCharMap[3] = new Character[]{'d','e','f'};
  numberToCharMap[4] = new Character[]{'g','h','i'};
  numberToCharMap[5] = new Character[]{'j','k','l'};
  numberToCharMap[6] = new Character[]{'m','n','o'};
  numberToCharMap[7] = new Character[]{'p','q','r','s'};
  numberToCharMap[8] = new Character[]{'t','u','v'};
  numberToCharMap[9] = new Character[]{'w','x','y','z'};
}
 
// Driver code 
public static void main(String[] args)
{
  int number[] = {2, 3, 4};
  printWords(number);
}
}