CSE1100-WordLink

Objectives

The aim of this request is to practise analysing a problem in an object-oriented manner, and designing and implementing an object-oriented solution.

Problem Description
WordLink is an English vocabulary game for two players. Players are required to present English words in turns, and the first character of the word must be the same as the last character of the previous word. For example, while player A and player B are playing the game, if A presents the word “grass”, then B has to give a word starting with ‘s’ which is the last character of “grass”. If B presents “sunny”, then A needs to supply a word starting with ‘y’. A word cannot be used twice in one game. The game can continue until one of the players loses. There are four scenarios in which a player loses the game.

1. the player cannot find a word to continue the game.
2. the player has presented a word which starts with a different character.
3. the player has supplied a repeated word.
4. the spelling of the word is incorrect
   In any case, if one player is lost, then the other player wins the game. A number of examples of the game are listed as below.

Example 1:

(Player A) "grass" – (Player B) "sunny" – (A) "yellow" – (B) "world" – (A) "dog" – (B) "grass"
The game is ended and Player A wins.

Example 2:

(Player A) "grass" – (Player B) "sunny" – (A) "yellow" – (B) "world" – (A) "dog" – (B) "out"
The game is ended and Player A wins.

Example 3:

(Player A) "grass" – (Player B) "sunny" – (A) "yellow" – (B) "world" – (A) "doog"
The game is ended and Player B wins.

In this request, you are required to build a program that plays WordLink with a kindergarten pupil. The pupil is player A and your program acts as player B.

A text file ( dictionary.txt ) containing a set of English words will be provided. You can assume that dictionary.txt contains all English words that a kindergarten pupil may know. Words to be used in playing the game must be selected from the set.

Each game should start by letting player A enter a word. Your program then needs to validate the word (ie. if the word is included in dictionary.txt ). If the word is invalid, then the game is terminated and your program (player B) wins; otherwise your program needs to search the dictionary to find and enter a proper word. Your program will then let player A to type a word to continue the game. This can go back and forth a number of times till either your program or player A wins.

Functional and Non-functional Requirements

Your program must satisfy the following functional and non-functional requirements.

Menu Driven

The program should be menu driven. It displays the menu displayed as Figure 1 at the start, and waits for the player to choose a function.

WordLink
A. set the difficulty level
B. display the dictionary
C. insert a word to the dictionary
D. play the game
E. exit
Select a function from the menu :

If A is selected, it allows the player to set a difficulty level.
If B is selected, it displays all words in the dictionary.
If C is selected, it inserts a new word into the dictionary.
If D is selected, it starts playing the game.
If E is selected, it saves all changes to dictionary.txt, and terminates the program execution.

Set the difficulty level

Your program should provide two difficulty levels for the games - level 1 and level 2. For the player, level 2 is more difficult than level 1. This is because all words in dictionary.txt can be selected for playing at level 2, while level 1 games only use those level 1 words in the text file. At the start of your program execution, the difficulty level is 1 by default.

If the player chooses to set the difficulty level, your program should prompt the player and wait for an integer (1 or 2) input. The difficulty level is then set up.

Display the dictionary

If this function is selected, your program displays on the monitor all words in the dictionary (including those being added). It displays words level by level with lower level at the front. Within each level, words are displayed alphabetically in an ascending order. They should be displayed 7 words in a line and 5 lines for a screen. The player can press any key to display the next screen.

Insert a word to the dictionary

The player can insert a new word into the dictionary. To insert a new word, the player needs to provide the word and the difficulty level. Your program must check to ensure the absence of the word before adding. If the word is existing, then insertion cannot be done and the player should be informed.

Play the game

A game starts by your program prompting the player to enter a word. After a word is entered, your program checks if the word exists in the dictionary. If it isn’t, then the player loses and the game is over. If it is, then your program searches the dictionary and selects the first proper word to continue the game. For instance, if “sad”, “sat”, “saw”, “say”, “sea”, “see”, “she”, “shy”, “sun” are all available for selection, your program chooses the first word which is “sad”.

The dictionary

After your program is started, it should read from dictionary.txt to create the dictionary. The dictionary in your program must be an array of linked lists shown in Figure 3. Each node represents a word and its level. Words must be sorted alphabetically in an ascending order on the linked list. If a new word is added, then the word with its level must be inserted to the linked list at a proper position.

Bonus Task

Instead of only being able to play against the computer, add a menu option for a two-player game and implement its functionality.

Code Segments

Below are code segments that must be included in your program.

public class DictionaryNode {
//object of the class represents a single word
  protected String word; // word to be stored
  private int level; // level of the word
  private DictionaryNode next;
  public DictionaryNode(String _word, int _level) {
  //add your implementation for the constructor
  }
  //add any other attributes or methods if needed
}

public class ListOfNodes {
//object of the class represents a linked list of words starting
//with a specific character.
  private DictionaryNode head = null; //head of the linked list
  //add any other attributes or methods if needed
}

public class Dictionary {
//object of the class represents the whole dictionery
  private ListOfNodes[] data;
  //add any other attributes or methods if needed
}

Program Development

The following is a suggested breakdown for completing this request:

Task 1 Creating the Menu

Create the menu display, collect user’s input and write a method stub for each menu option. Ensure that the correct function is called.

Task 2 File Handling

In Task 2, you need to consider all issues related to reading the text file (dictionary.txt) to obtain words and their levels. You can simply display contents read from the text file to ensure file reading is correctly conducted.

Task 3 Defining Classes

In this task, implement major classes for the request. This includes the necessary menu and interactions with the player for choosing options etc.

Task 4 Linked Lists

Implement classes required for linked lists and dictionary. Implement methods (such as insertInOrder, search etc) which are operations associated with the list and any other methods. Thoroughly test your linked list before integrating it into your program.