Question

IN JAVA

Create a class called Telephone that accepts a phone number in the constructor. For the purposes of this assignment, phone numbers may be any length. Make a method called getPossibilities that returns all possible phonewords for that phone number.

A phoneword is what you get when a phone number is converted in to letters. For example, the phone number 922-6966 could be re-written as ZAA-MZNO. Look at your phone to see where those letters came from.

DO NOT USE LOOPS.

////////The provided file cannot be edited\\\\\\\\

Problem4.java

import java.util.Scanner;

public class Problem4
{
  public static void main(String[] args) {
    Scanner keyboard = new Scanner(System.in);
    System.out.println("Enter a phone number");
    String phone = keyboard.nextLine();

    Telephone t = new Telephone(phone);
    for (String result : t.getPossibilities()) {
      System.out.println(result);
    }
  }
}

///////////Required Output\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

Standard Input	Files in the same directory
2	Problem4.java

Required Output

Enter a phone number\n
A\n
B\n
C\n

Standard Input	Files in the same directory
3	Problem4.java

Required Output

Enter a phone number\n
D\n
E\n
F\n

Standard Input	Files in the same directory
7	Problem4.java

Required Output

Enter a phone number\n
P\n
Q\n
R\n
S\n

Standard Input	Files in the same directory
1	Problem4.java

Required Output

Enter a phone number\n
1\n

Standard Input	Files in the same directory
234	Problem4.java

Required Output

Enter a phone number\n
ADG\n
ADH\n
ADI\n
AEG\n
AEH\n
AEI\n
AFG\n
AFH\n
AFI\n
BDG\n
BDH\n
BDI\n
BEG\n
BEH\n
BEI\n
BFG\n
BFH\n
BFI\n
CDG\n
CDH\n
CDI\n
CEG\n
CEH\n
CEI\n
CFG\n
CFH\n
CFI\n

Your Program's Output

Enter a phone number\n
ADG\n
BEH\n
CFI\n
ADG\n
BEH\n
CFI\n
ADG\n
BEH\n
CFI\n
ADG\n
BEH\n
CFI\n
 (Your output is too short.)

Test Case 8 - Failed

Standard Input	Files in the same directory
789	Problem4.java

Required Output

Enter a phone number\n
PTW\n
PTX\n
PTY\n
PTZ\n
PUW\n
PUX\n
PUY\n
PUZ\n
PVW\n
PVX\n
PVY\n
PVZ\n
QTW\n
QTX\n
QTY\n
QTZ\n
QUW\n
QUX\n
QUY\n
QUZ\n
QVW\n
QVX\n
QVY\n
QVZ\n
RTW\n
RTX\n
RTY\n
RTZ\n
RUW\n
RUX\n
RUY\n
RUZ\n
RVW\n
RVX\n
RVY\n
RVZ\n
STW\n
STX\n
STY\n
STZ\n
SUW\n
SUX\n
SUY\n
SUZ\n
SVW\n
SVX\n
SVY\n
SVZ\n

Your Program's Output

Enter a phone number\n
PSZ\n
QRZ\n
RUZ\n
PSZ\n
QRZ\n
RUZ\n
PSZ\n
QRZ\n
RUZ\n
PSZ\n
QRZ\n
RUZ\n
 (Your output is too short.)

Test Case 9 - Failed

Standard Input	Files in the same directory
2740	Problem4.java

Required Output

Enter a phone number\n
APG0\n
APH0\n
API0\n
AQG0\n
AQH0\n
AQI0\n
ARG0\n
ARH0\n
ARI0\n
ASG0\n
ASH0\n
ASI0\n
BPG0\n
BPH0\n
BPI0\n
BQG0\n
BQH0\n
BQI0\n
BRG0\n
BRH0\n
BRI0\n
BSG0\n
BSH0\n
BSI0\n
CPG0\n
CPH0\n
CPI0\n
CQG0\n
CQH0\n
CQI0\n
CRG0\n
CRH0\n
CRI0\n
CSG0\n
CSH0\n
CSI0\n

Answer 1

Code is as follows:

Telephone.java

************************************************************************************************************************************

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.stream.Collectors;

public class Telephone {
   private String phoneNumber;

   /**
   * @param phoneNumber
   */
   Telephone(String phoneNumber) {
       this.phoneNumber = phoneNumber;
   }

   // method declared private so as to use only in this class
   /**
   * @param phoneNumber
   * @param map
   * @return
   */
   private static List<String> permute(String phoneNumber, HashMap<Character, List<Character>> map) {
       if (phoneNumber.length() == 1) {
           return map.get(phoneNumber.charAt(0)).stream().map(ch -> ch.toString()).collect(Collectors.toList()); //if there is only one number
       }
       List<String> arr = permute(phoneNumber.substring(1, phoneNumber.length()), map); //recursive call to the permute method

       List<Character> curr = map.get(phoneNumber.charAt(0)); //current characters
       ArrayList<String> permutations = new ArrayList<>();

       arr.stream().forEach(str -> {
           curr.stream().forEach(c -> {
               permutations.add(c + str); //add in permutations
           });
       });

       Collections.sort(permutations); //sort the list
       return permutations; //return
   }

  
   /**
   * @return
   */
   public List<String> getPossibilities() {
       if (phoneNumber.length() == 0) {
           return new ArrayList<String>();
       }
       HashMap<Character, List<Character>> map = new HashMap<Character, List<Character>>(); //created a new hashmap
       //put all the characters allowed
       map.put('0', new ArrayList<Character>(Arrays.asList('0')));
       map.put('1', new ArrayList<Character>(Arrays.asList('1')));
       map.put('2', new ArrayList<Character>(Arrays.asList('A', 'B', 'C')));
       map.put('3', new ArrayList<Character>(Arrays.asList('D', 'E', 'F')));
       map.put('4', new ArrayList<Character>(Arrays.asList('G', 'H', 'I')));
       map.put('5', new ArrayList<Character>(Arrays.asList('J', 'K', 'L')));
       map.put('6', new ArrayList<Character>(Arrays.asList('M', 'N', 'O')));
       map.put('7', new ArrayList<Character>(Arrays.asList('P', 'Q', 'R', 'S')));
       map.put('8', new ArrayList<Character>(Arrays.asList('T', 'U', 'V')));
       map.put('9', new ArrayList<Character>(Arrays.asList('W', 'X', 'Y', 'Z')));
       return permute(phoneNumber, map); //call the method permute and return
   }
}

************************************************************************************************************************************

Problem4.java

************************************************************************************************************************************

import java.util.Scanner;

public class Problem4
{
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter a phone number");
String phone = keyboard.nextLine();

Telephone t = new Telephone(phone);
for (String result : t.getPossibilities()) {
System.out.println(result);
}
}
}

************************************************************************************************************************************

Screenshot of the code:

Output: