Thread: Help with magic square program

I got your magic box program to work. Here's the working version
with a couple of comments to show you what I did. I did some reformatting of your source code because it's the only way I could
debug it. Don't take it personally. If this is one of your first programs you have a good start. Try to cut down on the "else if's".

Code:

#include<stdio.h> 

#define SIZE 7 
#define RANGE SIZE*SIZE 

// changed void main(void) to int main(void)
int main(void) 
{ 

 // extra bracketing required here
 // see K&R second edition page 111
 int square[SIZE][SIZE]={{0}};

 int count=1;
 int col=SIZE/2;
 int row=0;

//build the magic square
 do{
  count++;
  row--;
  col++;

  if(row == -1 && col == SIZE)
  {
   row+=2;
   col--;
  }
  else if (row == -1)
   row=SIZE-1;
  else if(col == SIZE)
   col = 0;
  else if (square[row][col] != 0)
  {
   row+=2;
   col--;
  }

  // this line is moved from above
  square[row][col] = count; 

 }while (count < RANGE);

 //print magic square
 for(row=0;row<SIZE;row++)
 {
  for(col=0;col<SIZE;col++)
  printf("%6d",square[row][col]);
  printf("\n");
 }
} // end void main(void)

And just to highlight the obvious in the original code:
>void main(void)
is wrong... main returns an int.

Now this next comment is a personal opinion, so ignore it if you want..... Unreg, I try and avoid using do-while loops that have a lot of code in them. I believe it makes the program harder to read, because until I've read the complete loop, I've no idea what's controlling it. If you think your code must have do-while's, I'd suggest putting a comment at the top of the loop to help the reader see what the controlling factors are.