ZCW-PhoneBook/PhoneBook.java

import java.util.*;
import java.util.List;
import java.util.Arrays;
import java.util.Iterator;

/**
 * Created by leon on 1/23/18.
 */
public class PhoneBook {
    String name;
    String phoneNumber;
    TreeMap<String,ArrayList<String>> directory = new TreeMap<String,ArrayList<String>>();
    HashMap<ArrayList<String>,String> reverseDirectory = new HashMap<ArrayList<String>,String>();
    public PhoneBook(){

    }

    public TreeMap getDirectory(){
        return directory;
    }

    public HashMap<ArrayList<String>, String> invertMap() {
        for(String k: directory.keySet()){
            reverseDirectory.put(directory.get(k), k);
        }
        return reverseDirectory;
    }

    public TreeMap add(String name, ArrayList<String> phoneNumber){
        directory.put(name, phoneNumber);
        return directory;
    }

    public TreeMap removeRecord(String name){
        directory.remove(name);
        return directory;
    }

    public ArrayList<String> lookUp(String name){
        return directory.get(name);
    }

    public String reverseLookUp(String phoneNumber){
        this.invertMap();
        String answer = "";
        for(ArrayList<String> element: reverseDirectory.keySet()){
            if(arrayContains(element, phoneNumber) == true){
                answer = reverseDirectory.get(element);
            }
        }

        return answer;
    }

    public String display(){
        StringBuilder print = new StringBuilder("");

        for(String key : directory.keySet()){
            print.append(key + " " + printArray(directory.get(key)) + "\n");
        }

        return print.toString();
    }

    public String printArray(ArrayList<String> array){
        String result = String.join(", ", array);

        return result;
    }

    public boolean arrayContains(ArrayList<String> list, String phoneNumber){
        boolean correct = false;

        for(String element : list){
            if(phoneNumber.equals(element)){
                correct = true;
                break;
            }
        }

        return correct;
    }

    public TreeMap remove(String name, String phoneNumber){

        Iterator search = directory.get(name).iterator();
        while(search.hasNext()){
            if(search.next().equals(phoneNumber)){
                search.remove();
                break;
            }
        }
        return directory;
    }
}