Can someone please help fix this code so the program works? (2D arrays)

[busdude]

This program is supposed to accept a list of words from the user( user enters 'q' to stop the list), put the first word in the middle of 20 x 20 grid of chars, 2D array, and then goes through the list of words and arrange the words one by one into a crossword puzzle inside the grid of chars, if it is possible.

It compiles, but doesn't run properly right now.

import java.util.Scanner;

public class Puzzle
{
    public String[] read (String f)
    {
        String[] words = new String [20];
      

        Scanner in = new Scanner (System.in);
        int count = 0;
        while (in.hasNextLine())
        {
            words[count] = in.nextLine();
            count++;
        }
        return (words);
    }
    public void write (String f)
    {
        Scanner in = new Scanner(System.in);
        String word = "";

        System.out.println ("Enter the new words, 'q' to stop");
        while (word != "q");
        {
            if (word != "q")
            System.out.println(in.next());
        }

    }
   
}

and

/**
 * Write a description of class A2 here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */

import java.util.Scanner;

public class A2
{
    public static void main (String[] args)
    {    
        char[][] grid = new char [20][20];  //The puzzle
        Scanner in = new Scanner(System.in);
        String f; //File name
        Puzzle puzzle = new Puzzle(); //New puzzle
        
        f = in.nextLine();
        String[] words = puzzle.read(f); //Reading words from file
        
 for (int i = 0 ; i < words[0].length(); i++) //Placing the first word
        grid[10 + i][10] = words[0].charAt(i);
    int a = 1, b = -1; //Word number, Vert/Horiz
    while (words[a] !=null)
    {
        int ok = 0;
        if (  b == 1) //If horizontal
        {
            
            for (int i = 0; i<words[a].length();i++)
            {
                for (int j = 1; j < 19; j++)
                for (int k = 1; k < 19; k++)
                {
                    if (ok != 1)
                    if (grid[j][k] == words[a].charAt(i) && (j > i) && ( j +(words[a].length() - (i + 1))) < 20)
                    {
                        ok=0;
                    
                        for (int m = j - 1; m >= (j - i); m--)
                        {
                            if (grid[m][k - 1] > 0||grid[m][k] > 0||grid[m][k + 1 ] > 0)
                            ok = -1;
                            if (k < 0||k > 19||m < 0)
                            ok = -1;
                            if (grid[m - 1][k] > 0)
                            ok = -1;
                        }
                        for (int m = j + 1; m <= j + (words[a].length()-(i + 1));m++)
                        {
                            if (grid[m][k - 1] > 0||grid[m][k] > 0||grid[m][k + 1] > 0)
                            ok= -1;
                            if (k < 0||k > 19||m >= 20)
                            ok = -1;
                            if (grid[m + 1][k] > 0)
                            ok = -1;
                        }//Checking adjacent
                        if (ok == 0)
                        {
                            ok=1;
                            for (int y = j - i; y < (j - i) + words[a].length();y++)
                            grid[y][k] = words[a].charAt (y -(j - i));
                            System.out.println ("Yes" + words[a]);
                        }
                        
                    }//If letters the same
                }//Checking puzzle for letters
            }//Going through letters of word
            if (ok == 0)
            ok = -1;
        }//If horizontal
        if (b == -1) //If vertical
        {
            if (ok!= 1)
            for (int i = 0; i<words[a].length();i++)
            {
                for (int k = 1; k < 19; k++)
                for (int j = 1; j < 19; j++)
                {
                    if (ok!=1)
                    if (grid[j][k] == words[a].charAt(i) && (k > i) && (k + (words[a].length()-(i + 1)))<20) 
                    {
                        ok = 0;
                    for (int m = k - 1; m >= (k - i); m--)
                    {
                        if (grid[j - 1][m] > 0||grid[j][m] > 0||grid[j + 1][m] > 0)
                        ok = -1;
                        if (j < 0||j > 19||m <0)
                        ok = -1;
                        if (grid[j][m - 1]>0)
                        ok = -1;
                    }
                    for (int m = k + 1; m <= words[a].length() - (i + 1); m++)
                    {
                        if (grid[j - 1][m] > 0||grid[j][m] > 0||grid[j + 1][m]>0)
                        ok = -1;
                        if (j < 0||j > 19||m >= 20)
                        ok = -1;
                        if (grid[j][m+1] > 0)
                        ok = -1;
                    }//Checking adjacent                      
                    
                    if (ok == 0)
                    {
                        ok = 1;
                        for (int y = k - i; y <(k - i) + words[a].length(); y++)
                        grid[j][y]=words[a].charAt (y -(k - i));
                        System.out.println ("Vert " + words[a]);
                    }
                }
            }//Checking for letters
        }//Going through letters of word
        if (ok == 0)
        ok = - 1;
    }//If vertical
    b =  b * -1;
    a++;
    }//While there are words
    }//Main
}//Class

[matzahboy]

What's wrong with it? What happens when it runs? It's much harder to debug when you don't know what the problem is.

[busdude]

currently the problem is the list doesn't end when the person enters 'q'. this program originally had a GUI which I'm trying to remove so I don't know what is leftover from it. it could be some error with a file reader or something