two dimensional arrays

[estera]

I have an assignment that I'm having problems with and I was wondering if you could help me. What I have to do is to generate a 5x5 two-dimmensional array with 25 two-digit numbers, but I have to make sure there are no duplicates. Then I have to cover 10 randomly picked numbers from the array with "XX", but I have to make sure that none of the 10 covered numbers make 5 in a row either horizontally, vertically or diagonally.

So what I'm having problems with is how to make sure there are no duplicates, and how to make sure that none of the 10 covered numbers make 5 in a row.
This is the code, what I did so far.
Thank you.

import acm.program.*;
import acm.graphics.*;
import acm.io.*;
 
class LingoBoard1 extends ConsoleProgram
{
 
  void main()
  {
 
  int[][] matrix = createArray();
 
  println("The Lingo board is: ");
  displayArray(matrix);
 
  println("The board with 10 elements covered is: ");
  matrix = coverArray(matrix);
  displayArray(matrix);  
  }
  int[][] createArray ()
  {
  int[][] matrix = new int[5][5];
  boolean isDuplicate = true;
  int row, column;
 
   for (row = 0; row < 5; row++)
    for (column = 0; column < 5; column++)
       while(isDuplicate)
      {
         matrix[row][column] = (int)(Math.random() * (99-10+1)) + 10;
           isDuplicate = checkDuplicate(matrix,row,column);
 
       }
  return matrix;
  }
 
  void displayArray (int[][] matrix)
  {
    for (int row = 0; row < 5; row++)
    {
     for (int column = 0; column < 5; column++)
       {
           print(matrix[row][column] + " ");
       }
      println(); 
    }
  } 
 
  boolean checkDuplicate(int[][] matrix,int i, int j)
  {
    boolean b = false;
 
     for (int row = 0; row < 5; row++)
     for (int column = 0; column < 5; column++)
        if(matrix[row][column] == matrix[i][j])
          b = true;
          else b = false;
 
     return b;
    }                     
 
  int[][] coverArray(int[][] a)
  {
 
  //int[][] a;
  int i,j;
 
  for(i = 0; i < 5; i++)
   {
    j = (int)(Math.random()*5);
    a[i][j] = 'x';
   }
  for(j = 0; j < 5; j++)
   {
    i = (int)(Math.random()*5);
    a[i][j] = 'x';
   }  
  return a;
  }   
  public static void main(String[] args) 
  {
    new LingoBoard1().start();
  }
  public void run() { main(); }
}

[Nepomuk]

Hi estera! Welcome to TSDN!

Do I understand correctly, you have to avoid thing like this

xx  xx  xx  xx  xx
21  22  23  24  25
31  32  33  34  35
41  42  43  44  45
51  52  53  54  55
 

or this

xx  12  13  14  15
xx  22  23  24  25
xx  32  33  34  35
xx  42  43  44  45
xx  52  53  54  55
 

or this

xx  12  13  14  15
21  xx  23  24  25
31  32  xx  34  35
41  42  43  xx  45
51  52  53  54  xx
 

or this

11  12  13  14  xx
21  22  23  xx  25
31  32  xx  34  35
41  xx  43  44  45
xx  52  53  54  55
 

Correct?

If so, you have to check if it would make a row as soon as you're setting #5 - #10. You could have three (or four) methods:

private boolean checkHorizontal(int x, int y)
{
   // ...
}
 

private boolean checkVertical(int x, int y)
{
   // ...
}
 

private boolean checkDiagonal(int x, int y)
{
   // ...
}
 

and use each of those to check, if setting xx at the positon (x,y) would create a line.

Greetings,
Nepomuk

[estera]

Hi estera! Welcome to TSDN!

Do I understand correctly, you have to avoid thing like this

xx  xx  xx  xx  xx
21  22  23  24  25
31  32  33  34  35
41  42  43  44  45
51  52  53  54  55
 

or this

xx  12  13  14  15
xx  22  23  24  25
xx  32  33  34  35
xx  42  43  44  45
xx  52  53  54  55
 

or this

xx  12  13  14  15
21  xx  23  24  25
31  32  xx  34  35
41  42  43  xx  45
51  52  53  54  xx
 

or this

11  12  13  14  xx
21  22  23  xx  25
31  32  xx  34  35
41  xx  43  44  45
xx  52  53  54  55
 

Correct?

If so, you have to check if it would make a row as soon as you're setting #5 - #10. You could have three (or four) methods:

private boolean checkHorizontal(int x, int y)
{
   // ...
}
 

private boolean checkVertical(int x, int y)
{
   // ...
}
 

private boolean checkDiagonal(int x, int y)
{
   // ...
}
 

and use each of those to check, if setting xx at the positon (x,y) would create a line.

Greetings,
Nepomuk

Thanks. One more question. How would I check to see if the setting XX creates a line? Can you give me an example for one of the methods?

[Nepomuk]

Thanks. One more question. How would I check to see if the setting XX creates a line? Can you give me an example for one of the methods?

I won't write any of the methods for you, but here's how it would work:

private boolean checkHorizontal(int x, int y, int[][] matrix)
// you can leave out the last part, if your matrix is defined globally
{
   // you have the y-value of the number to be set, so check if there are 5 - 1 = 4 Numbers in that line covered already
   int covered = 0;
   // your code here
   return ...; // What do you return?
}
 

Greetings,
Nepomuk