Problem with reading from an array

[Afro]

As the title suggests im having trouble with writing from an array.

It seems as if even the i give the board[x][y] the correct values it's still reading from
the wrong point, i've looked through my code and cant find anything that's wrong, maybe you can help?

This is a simplified version of the code, with only the areas that are a problem.

#include <iostream>

#define WHITE_KING 6 // define all chess pieces for ease of use
#define WHITE_QUEEN 5 
#define WHITE_TOWER 4
#define WHITE_RUNNER 3
#define WHITE_HORSE 2
#define WHITE_PEASANT 1
#define EMPTY 0       
#define BLACK_PEASANT -1
#define BLACK_HORSE -2
#define BLACK_RUNNER -3
#define BLACK_TOWER -4
#define BLACK_QUEEN -5
#define BLACK_KING -6

using namespace std;

void initboard(void);
void drawboard(void);

int board[7][7];//global board variable

int main()
{
    initboard();
    drawboard();
    
    system("PAUSE");//hold
}


void initboard(void)//initiate the board
{
     int x,y;
     for(y=0;y<=7;y++)//make sure all values are at zero
     {
        for(x=0;x<=7;x++)//loop through columns values, then go to the next row and redo
        {
          board[x][y]=EMPTY;
        }
     }
     for(x=0;x<=7;x++)board[x][1]=WHITE_PEASANT;//white should be at the top rows
     for(x=0;x<=7;x++)board[x][6]=BLACK_PEASANT;//black should be at the bottom rows
     
     board[0][7]=BLACK_TOWER;//boring initialization stuff
     board[1][7]=BLACK_HORSE;
     board[2][7]=BLACK_RUNNER;
     board[3][7]=BLACK_QUEEN;
     board[4][7]=BLACK_KING;
     board[5][7]=BLACK_RUNNER;
     board[6][7]=BLACK_HORSE;
     board[7][7]=BLACK_TOWER;
     
     
     board[0][0]=WHITE_TOWER;
     board[1][0]=WHITE_HORSE;
     board[2][0]=WHITE_RUNNER;
     board[3][0]=WHITE_QUEEN;
     board[4][0]=WHITE_KING;
     board[5][0]=WHITE_RUNNER;
     board[6][0]=WHITE_HORSE;
     board[7][0]=WHITE_TOWER;
}
void drawboard(void)
{

     int x,y;
     cout << " ";//proper alignment
     for(x=0;x<=7;x++)cout << "   " << x << "   "; // the numbers above 
     cout << endl;// new row for layout
     
     
     for(y=0;y<=7;y++)
     {
      cout << y;//numbers at the side of the grid
      
      for(x=0;x<=7;x++)//loop through columns values, then go to the next row and redo
      {
       if(board[x][y]>=0)cout << " | " << board[x][y] << " | ";
       else cout << " |" << board[x][y] << " | ";//one less space for negative value alignment
      }
      cout << endl;
      }
}

If anyone has encountered this problem (or simply knows that i am doing something wrong) please do tell! I've been trying to fix this for a long while!

Thanks in advance.

[mike_g]

Your board is sized to be 7 elements wide on each dimension, yet you are trying to deal with a board that is 8*8:

for(y=0;y<=7;y++)

You might want to change the size of your board:

int board[8][8];//global board variable

[Dino]

Your board is 7X7, so your can't use an index of 7 - you have to stop at 6. Therefore, don't code

x <= 7

code

x < 7

[Dino]

Duh. Boards are 8X8. Good point Mike!

[Afro]

oh man, thanks. That's such a silly error to make.
But i thought defining an array as [7][7] would give eight different variables?
As in: 0 1 2 3 4 5 6 7?
Or i might just be totally off there.

EDIT: Because otherwise, i should also have to set up my loops so they go between the values 1 and 8 instead of 0 and 7, correct?

[Dino]

When you define an array, you specify the number of elements you want: 8 in this case.

When you iterate through an array, since you start at zero, you stop after 8 iterations - which is 7.

[Afro]

Ah, alright, makes sense now, thanks for the help Todd, and Mike

/thread over