Logic Problem involving loops and arrays

tox0tes · Oct 27th, 2007, 04:56

Hey everyone,
I am trying to create a sudoku solver in C. I am working on this one function that is supposed to go through each square and compare it to every other square, looking to see if the value in the square matches the value in any other square in its 3x3 grid, row, or column. puzzle[x][y] is the 2dimensional array containing each value that has been submitted. For example, puzzle[4][2] contains the value on column 4 and row 2...

The code i am having a problem with is right here, where I want to test the current square to see whether it conflicts with the value in another square in either its 3x3 grid, row, or column.

Code: Select all

if((x == a && y != b) || (y == b && x != a) || (!((x == a && y != b) || (y == b && x != a)) && ((int)(x / 3) == (int)(a / 3) && (int)(y / 3) == (int)(b / 3))))

The entire code is below.

Code: Select all

int validator (int puzzle[][9])
{
    int x;
    int y;
    int a;
    int b;
    
   for(y=0; y<9; y++)
    {
       for(x=0; x<9; x++)
        {
           if(puzzle[x][y] != '0')
            {
               for(b=0; b<9; b++)
                {
                   for(a=0; a<9; a++)
                    {
                     if((x == a && y != b) || (y == b && x != a) || (!((x == a && y != b) || (y == b && x != a)) && ((int)(x / 3) == (int)(a / 3) && (int)(y / 3) == (int)(b / 3))))
                  {  
                     return 0;
                  }
                      else
                      {
                         return 1;
                      }
                   }
                } 
            }
            else
            {
               return -1;
         }
        }
    }
   return 2;
}

c010depunkk · Oct 27th, 2007, 11:10

I been trying this out a bit but I'm not getting anywhere. That's one huge IF statement you got there

Haven't quite figured it out yet....

I'll get back to you when I have something to show!

tox0tes · Oct 27th, 2007, 18:39

basically what it does is it loops through each row and column, then loops through each "other" row and column (signified by a and b instead of x and y). For each one, it tests whether the first square (x,y) contains similar values as in the other square (a,b). If it does, then it returns 0, if not, then it returns 1.

I am trying to figure out how to only test squares that are in its current row, in its current column, and in its current 3x3 grid. That is what the if statement is testing for.

tox0tes · Oct 27th, 2007, 18:48

i just realized something: I was mistakenly continuing if puzzle[x][y] != '0', when it should actually be if puzzle[x][y] == '0'..... since an input of '0' means that that is an empty square that the program should consider. If it isn't '0', the the program should stop at the current puzzle[x][y] and return -1 since it is already occupied by a number 1-9.

alexgeek · Oct 27th, 2007, 19:42

Wow mind-boggling.
Is this solved now?

tox0tes · Oct 28th, 2007, 03:11

no still not solved, but I wasn't expecting anyone to be able to do it or even devote enough time to understand it. It's a really complex problem.