Thread: A Simple Life Game Code - Near the end ?

With a lot of help of people of this forum, Codecall forum, and also Daniweb forum, i made this code. What it is purpose ? It's an adaptation of life, using only basic concepts of C (it's for a introductory C course, so i cannot use stacks, queues, dynamic allocation, ... well i didn't learned that yet, also. ). So what the code is supposed to do:

1 - It has the main function and two others (count_neighbors and generation)
2 - The function count_neighbours as name says count the neighbours of a alive cell of a char matrix predefined with fixed size.
3 - The function generation use the function count_neighbours applyed in each i, and each j (with a for loop) and then let this value in alive_neighbours variable. Well, then , there exists 4 tests depending of the value of alive_neighbours. The purpose here is create the next generation predefined char matrix C.
4 - In the function main, we create a matrix of random numbers, give it the chance of 40% cells to be alive using

Code:

A[i][j] = rand() % 10;  // Aij value is between 0 and 9

and

Code:

if (A[i][j]<=3) B[i][j] = 'X';   //X for alive cells

and creating the char matrix B (based on previous one) in a size 2 rows and columns larger than the integer matrix, so all cells can count its neighbours properly.
5 - That's where i'm stopped right now. It seems that generation function somehow isnt working. Could you give me a direction ? Thanks for the help until now.
(P.S.: I know I should print only the part where supposed there's an error, but I like to share the code also, cause i think its one of the less harder implementation.)

Code:

 #include <stdio.h>
#include <stdlib.h> 
#include <string.h>
#include <time.h> 

//Global variables
    int i,j=0; // Initialize the variables i,j (row and column)
    int x,y=0; // Initialize the variables x,y (used in function count_neighbours)
    int alive_neighbours; //
    int alive,count; // Initialize the variable that control the alive cells 
    int A[40][40]; // Define the 40x40 integer matrix 
    char B[42][42]; // Define the 42x42 initial char matrix 
    char C[42][42]; // Define the 42x42 transitory char  matrix


// Function count neighbours
int count_neighbours(int i, int j)
{
     int count=0;
	for (x = -1; x <= +1; x++)          
   	   {
	      for (y = -1; y <= +1; y++)
		    {
			   if (B[i + x][j + y] == 'X' && (x!=0 || y!= 0))
			  	 count++;
		    }
       }
  	return count;
}

//Function generation - apply the necessary conditions.
int generation()  
{
int alive_neighbours=0;
   for (i=1; i<41; i++)
   {
      for (j=1; j<41; j++)
      {
        alive_neighbours = count_neighbours(i,j);
        if(alive_neighbours < 2)
        {
              C[i][j] = '.'; //make C[i][j] a dead cell
        }            
        if (alive_neighbours >= 2  &&  alive_neighbours <= 3 )
        {
              C[i][j] = B[i][j]; //copy the alive cell B[i][j] to C[i][j]
        }           
        if(alive_neighbours > 3)
        {
              C[i][j] = '.'; // make C[i][j] a dead cell.
        }           
        if(alive_neighbours == 3 && B[i][j]=='.')
        {
              C[i][j] = 'X'; //make C[i][j] alive
        }          
      }printf("%1c", C[i][j]); // Print . or X of new matrix
                   if(j==40) printf("\n"); // Organize the matrix
   }
 //  return 0; 
}

int main()                                     
{
    printf("Este codigo trabalha apenas com matrizes LIFE quadradas de 40x40:\n");        
    //This code only works with square matrix dimension 40.                       

    printf("\nMatriz LIFE:\n\n");       
    srand(time(NULL));  //Activate function srand
    for(i = 0; i < 40; i++)  //loop - i to 40
    {
         for(j = 0; j < 40; j++) //loop - j to 40
              {
                   A[i][j] = rand() % 10;  // Aij value is between 0 and 9
                   printf("%1d", A[i][j]);  // Print each Aij
                   if(j==39) printf("\n"); // Organize the matrix         
              }
                   
    }
    printf("\n");
    printf("\n");
    
    for(i = 0; i < 40; i++)  //loop - i to 40
    {
         for(j = 0; j < 40; j++) //loop - j to 40
              {
                   if (A[i][j]<=3) B[i][j] = 'X';   //X for alive cells
                   else B[i][j] = '.'; // . for dead cells
                   printf("%1c", B[i][j]); // Print . or X 
                   if(j==39) printf("\n"); // Organize the matrix
              }
                   
    }    
printf("\n");

generation();   
//printmatrix(); 
getch();
return 0;
}