We provide you with code for implementing the following game: given a rectangle of letters, find all dictionary words that consist of consecutive letters on the board (up-down, down-up, left-right, or right-left).

import java.util.ArrayList;

public class WordGame {

/*

* Returns all strings that appear

* as a consecutive horizontal or vertical sequence of letters

* (left-right, right-left, up-down, or down-up)

* in the array board and also appear in dict.

* Note that the same word may appear multiple times

* on the board, and will then be multiple times in

* the returned array.

*

* dict is assumed to be in alphabetical order

* board is assumed to be rectangular

*/

public static String[] search(String[] dict, char[][] board) {

/*The following line contains , this means

* that the ret is an ArrayList that contains String. It is an

* ArrayList of only Strings.

*/

ArrayList ret = new ArrayList();

int height = board.length;

// Set width to 0 for an empty board,

// and to the width for first line otherwise,

// because we assume the board is a rectangle

int width = board.length==0 ? 0 : board[0].length;

// TODO Generate substrings of the board

// and check if they are in the dictionary

// by calling inDictionary (which you implement).

// If they are, use ret.add to add them

// to the array that gets returned.

// Character.toString, String+char, and String+=char

// can all be useful here.

// You may want to see https://docs.oracle.com/javase/8/docs/api/java/lang/String.html

// and https://docs.oracle.com/javase/8/docs/api/java/lang/Character.html

//

// TODO (10% of your grade): if your board

// has height h and width w, how many strings

// do you need to check using inDictionary

// (assume that you do nothing to filter out

// duplicates or, equivalently, that the board

// is such that there are no duplicates)

// ANSWER:

// EXPLANATION OF THE ANSWER:

// This line converts ArrayList to String []

return ret.toArray(new String[0]);

}

}

--------------------below is the code for the main function class -------------------

import java.io.*;

/*

* THIS IS THE FILE FOR TESTING YOUR CODE

*/

public class WordGameDriver {

public static void main(String[] args) {

String dictionaryFileName = "src"+File.separatorChar+"hw4"+File.separatorChar+"dictionary.txt";

String boardFileName = "src"+File.separatorChar+"hw4"+File.separatorChar+"board.txt";

String [] dict = WordGameHelperClass.readDictionary(dictionaryFileName);

if (dict == null) return;

char [][] board = WordGameHelperClass.readBoard(boardFileName);

if (board == null) return;

String [] result = WordGame.search(dict, board);

for (String w : result) {

System.out.println(w);

}

}

}