WordSearch.java

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

public class WordSearch {

    private char[][] board;
    private Random rand;
    private ArrayList<String> wordList;
    private ArrayList<String> words;
    private String blanks;

    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) {
	    System.out.println(e);
	    System.exit(0);
	}
    }

    public WordSearch(int rows, int cols) {
	rand = new Random();
	words = new ArrayList<String>();
	board = new char[rows][cols];
	for (int i=0;i<rows;i++) 
	    for (int j=0;j<cols;j++) 
		board[i][j]='-';
	readWords("wordlist");
	while (wordList.size() > 0)
	    addWordRandomLoc();
	blanks = toString();
	fillInBlanks();
    }

    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 {
		    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 void addWordRandomLoc() {
	int w = rand.nextInt(wordList.size());
	String word = wordList.get(w);
	wordList.remove(w);
	int r;
	int c;
	int deltaR;
	int deltaC;

	boolean valid = false;
	int counter = 0;
	while (!valid) {
	    r = rand.nextInt(board.length);
	    c = rand.nextInt(board[0].length);
	    deltaR = rand.nextInt(3)-1;
	    deltaC = rand.nextInt(3)-1;

	    if (addWord(r,c,deltaR,deltaC,word)) {
		words.add(word);
		valid = true;
	    }
	    else if (counter >= 1000) //Gives up on word after 1000 tries
		valid = true;
	    counter++;
	}
    }

    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 ArrayList<String> getWords() {
	return words;
    }

    public String getBlanks() {
	return blanks;
    }

    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;
    }


}