WordSearch.java

import java.util.*;
import java.io.*;

public class WordSearch {

    private char[][] board;
    private Random rand;
    private ArrayList<String> wordList;
    ArrayList<String> answer = new ArrayList<String>();

    private void readWords(String filename) {
	wordList = new ArrayList<String>();
	try {
	    Scanner sc = new Scanner(new File(filename));
	    while (sc.hasNext()) {
		String s =sc.nextLine();
		wordList.add(s);
	    }
	} catch (FileNotFoundException e) {
	    // if we can't open the file we
	    // exit the program
	    System.out.println(e);
	    System.exit(0);
	}
    }

    public WordSearch(int rows, int cols) {
	rand = new Random();
	readWords("wordlist");
	//System.out.println(wordList);
	board = new char[rows][cols];
	for (int i=0;i<rows;i++) 
	    for (int j=0;j<cols;j++) 
		board[i][j]='-';

    }

    public WordSearch() {
	this(20,20);
    }

    public boolean addWord(int row, int col, int deltaR, int deltaC,  String word) {

	/* make sure deltas are in range */
	if (deltaR < -1 || deltaR > 1 || deltaC < -1 || deltaC > 1 || 
	    (deltaR==0 && deltaC==0) )
	    return false;

	/* see if we can place the word */
	int r = row;
	int c = col;
	for (int i=0; i < word.length(); i++) {
		try {
		    //j=10/i; <-- this is only to show the Arithmetic exception
		    if ( board[r][c] != '-' && board[r][c]!=word.charAt(i)) {
			return false; // we return false since we can't add the word
		    }
		} catch (ArrayIndexOutOfBoundsException e) { // Handle the array one
		    return false;  // we return false since we can't add the word
		}
		r = r + deltaR; 
		c = c+ deltaC;
	    }
    	
	/* if we get here, we can add the word */
	r = row;
	c = col;
	for (int i=0; i < word.length(); i++) {
	    board[r][c]=word.charAt(i);
	    r = r + deltaR; 
	    c = c+ deltaC;
	}
    	
	
	return true;
    }

    public boolean addWordH(int r, int c, String w) {
	return addWord(r,c,0,-1,w);
    }
    public boolean addWordV(int r, int c, String w) {
	return addWord(r,c,1,0,w);
    }
    public boolean addWordD(int r, int c, String w) {
	return addWord(r,c,1,1,w);
    }
    
    public boolean addWordRandomLoc(String w) {
	int r = rand.nextInt(board.length);
	int c = rand.nextInt(board[0].length);
	int deltaR = rand.nextInt(3)-1;
	int deltaC = rand.nextInt(3)-1;

	return addWord(r,c,deltaR,deltaC,w);

    }
    public boolean makePuzzle(int numWords){
	Random r = new Random();
	if (numWords > wordList.size())
	    return false;
	int i = 0;
	while (i < numWords){
	    int index = r.nextInt(numWords);
	    while (answer.contains(wordList.get(index))){
		index = r.nextInt(numWords);
	    }
	    int count = 0;
	    boolean worked = false;
	    while (!worked && count < 30){
		worked = addWordRandomLoc(wordList.get(index));
		if (worked){
		    answer.add(wordList.get(index));
		}
		count = count + 1;
	    }  
	    i = i + 1;
	}
	return true;
    }


    public void fillInBlanks() {
	for (int r = 0; r < board.length; r++)
	    for (int c=0;c<board[0].length;c++) {
		if (board[r][c]=='-')
		    board[r][c]=(char)('a'+(char)rand.nextInt('z'-'a'));
	    }
    }
    public String toString() {
	String s = "";
	for (int i=0;i<board.length;i++) {
	    for (int j=0;j<board[i].length;j++) {
		s=s+board[i][j];
	    }
	    s=s+"\n";
	}
	return s;
    }
    public ArrayList<String> getAnswer(){
	return answer;
    }


}