Thread: Game of life program

Well, did you try it?

I see 25x25 grids now. They look like they change from generation to generation. I haven't analyzed to see if it's doing the right thing, (mostly because I don't know what that is) but it's doing something.

Originally Posted by nonoob

You're almost there. When you initialize the array[][] you should also assign the same values to n_array[][]. Otherwise n_array will have garbage in its outer edges because they are never initialized. This garbage will be placed in the array after 1st generation.

I didn't understand what you mean.
I think,I have already done what you want
Actually, the output is not working properly.
@nonoob
Please show over the code

Code:

#include <stdio.h> 
#include <stdlib.h>
#include <time.h>
#define ROWS 25
#define COLS 25
void game_of_life(char o_arr[][COLS], char n_array[][COLS]);
int checkx(char arr[][COLS],int row, int col);
int main(void)
{
	char array[ROWS][COLS],n_array[ROWS][COLS];
	srand(time(NULL));
	int i, j, r_integer[ROWS][COLS], num_gen;
	for(i=0;i<ROWS;i++){
		for(j=0;j<COLS;j++){
			r_integer[j][i] = (rand() % 100) > 50 ? 1 : 0;
		}
	}
	for(i=0;i<ROWS;i++){
		for(j=0;j<COLS;j++){
			  if(r_integer[j][i] == 0)
                  array[j][i]=' ';
              else
				  array[j][i]='X';            
			}
		}			
	for(i=0;i<ROWS;i++){
		printf("\n");
		for(j=0;j<COLS;j++){
			printf("%c", array[j][i]);
		}
	}
	for(num_gen=0;num_gen<4;num_gen++){
		printf("\nGeneration: %d\n", num_gen+1);
		game_of_life(array,n_array);
		for(i=0;i<ROWS;i++){
			for(j=0;j<COLS;j++){
				array[j][i]=n_array[j][i];
			}
		}
		for(i=0;i<ROWS;i++){
			printf("\n");
			for(j=0;j<COLS;j++){
				printf("%c", n_array[j][i]);
			}
		}
	}
	return(0);
}
void game_of_life(char o_arr[][COLS], char n_array[][COLS])
{
	int i, j, num_neighbors=0;
	for(i=0;i<COLS;i++){     
		for(j=0;j<ROWS;j++){
			if ((o_arr[j][i])=='X'){
				num_neighbors = checkx(o_arr, j+1, i+1);
				if( num_neighbors <4 && num_neighbors >= 2)
					n_array[j][i]='X';
				else if (num_neighbors >=4 || num_neighbors < 2)
					n_array[j][i]=' ';
            }
			else {
				num_neighbors=checkx(o_arr, j+1, i+1);
				if (num_neighbors == 3)  
					n_array[j][i]='X';                
				else 
					n_array[j][i]=' ';
              }
          }
      }
}
		
int checkx(char arr[][COLS],int row, int col)
{
      int num_neighbors = 0;
      if ((arr[row-1][col-1])=='X')
          num_neighbors++;
      if ((arr[row-1][col])=='X')
          num_neighbors++;
      if ((arr[row][col-1])=='X')
          num_neighbors++;
      if ((arr[row][col+1])=='X')
          num_neighbors++;
      if ((arr[row+1][col-1])=='X')
          num_neighbors++;
      if ((arr[row+1][col])=='X')
          num_neighbors++;
      if ((arr[row+1][col+1])=='X')
          num_neighbors++;
      return(num_neighbors);
}

output is:

Code:

X XXX X  X  X   XX  XXX  
 XX    XX   XXXXX X XXX X
XXXX  XX      X    XXXX  
  XX XX   X              
 X  X     XX    XX X  XX 
X XX XXXX        X   XXXX
X X   X    X X X X  X XX 
X      XXXX  XXX XX XX   
XX   XXXX  XX   XX XXX X 
 XXX XX XX  X X       XXX
 XXXX X  X  X  X XXX X  X
  X X  XXXXX  X    XX    
XX   X  XXXXX X  XX X X  
X  X X XXXXX X   XXX XXXX
X X      XXX X    X   X X
XX  XXX X  X X    XX  XXX
    X XXX XX XX XXX    X 
X X  X    X  X X  XXX X X
X XX  XX XX XXX X XX   X 
X X   X XXX X   X  X XXX 
X XX       XX     XX XX X
XX XX X  XXX X X XXXXXX X
    XXXX X X   XX XX XXXX
XXX X X  X      XXXX   XX
XXXXX   XXXX   XX  XXXXX 
Generation: 1

   XX X      XXX X    X  
  X XXXXX    X XX X  XX  
     XX       X   XX  X  
   X  X   X         XXX  
 X XXX   XXX    XX XX  X 
  XXX   X  X    XX X   X 
    X  X X    X XX    X  
 X  X    XXX  XXX X      
  X     X  XX XX  X  X X 
     X    X  X   XXX X XX
 X X  X    XX  X    XX   
 XXXXX     X  X X  X  X  
 X X X      X     XX     
  X XXX      X     X   XX
X X XX    X XX   XX  X  X
XX X X   X  XXX    X    X
X X X  X X    X          
 XX XX   X XXX XX     X X
       X   X XX   X X XX 
 X    XX   XX          X 
X            X XX       X
 X    X X XX XX        XX
 X X X  X              XX
   X  XXX           XXXX 
    XXX         XX    X  
Generation: 2

      X     X XX X  XXX  
  XX   XX    XXXX X  XX  
     XX X     X  X XXXX  
      X   X    X XXX  X  
 X  XX    XX  X    XXX X 
   XX   X                
    X     X X  X X    X  
    X     XX X   XX  X   
  X     X   X XX XX    X 
    X    XX XX X   XX  X 
X   X     X X X  X XX    
X    X     XX X XXXX  X  
XX   X      X   X XX     
     X    X  X   XXX   XX
  X XX    XX X   X      X
 X  XX   XX  X          X
X   XX X   X  X       X  
XXX X       XXXXX   XX  X
       X     XX   X XXXX 
X    XXX XX XX         X 
X     X    X XXX       XX
        X XX X         XX
 X   XX X           X XX 
 XXX X X           X XX  
      X     XX X   X     
Generation: 3

    XXX          X    X  
  XX X XX   X     XX  X  
   X XX X    X X     XX  
  X   X   X    X  XX X   
 XX X   XXXX  X    XXX   
   XX   X X    X         
    X       X    X   XX  
  X      X   X XX    X   
  X     X  X  X X      X 
    X   XX X XX    XX    
X  XX      X   X   XX    
X  X X    XX  XX   X  X  
XX   X    XXX  X  XX     
  X XX   XX  X    X    XX
     X     X X          X
 XX XX   XX  XX       X X
X X XX     X  X    X  X  
XXX XX         XX XX  X X
       X  XX  X   X X  X 
X   XX XX X  X       X X 
X   X X       X        XX
 X      X XX         XXX 
 X XX X            XXXX  
 XXXXX      XX   XX XX   
      X        X  X      
Generation: 4

  X   X          X    X  
  X X  XX    X    XXX X  
X XXXX X       X  X XX   
 X    X   X   X  XX  X   
 X XX    X X         X   
  XXX   X X   XX         
            XX X      X  
  X    XXX X X XX    X   
        X  X X    X      
  XXX   X  XX X  X XX    
X   X      X XXX  XXX    
XX   X     XXXXX X X  X  
X  XXX      X     X      
X X XX      XX         XX
  X XX   XXXXX        X X
 X   X   X  XX   X  X   X
   XXX   X   XX XXXX     
XXX XX        XXX  XXXX X
       XX XX X    X   XX 
X    X XXXX         X XX 
X X X X            XX XX 
X XXX   X XX          X  
     X           X   X   
            XX XXXXXX    
   XX X        X

Originally Posted by mike65535

Well, did you try it?

I see 25x25 grids now. They look like they change from generation to generation. I haven't analyzed to see if it's doing the right thing, (mostly because I don't know what that is) but it's doing something.

This is a game

It would be a lot easier to see if it was working, if you initialised your array to say a glider, rather than some random pattern.

I shrunk your ROWS and COLS to 5 for testing, which made it much easier. I noticed a three problems:
1. Why are you calling checkx with j+1 and i+1? You should just be using j and i, so it corresponds to the same grid coordinate you checked in if (o_arr[j][i]).
2. You're missing the following case from your checkx function: arr[row-1][col+1]
3. You don't properly handle the corner/edge cases. Your checkx code needs to make sure that it doesn't go out of bounds of the grid, so you need something like:

Code:

if (row > 0 && col < COLS-1 && arr[row-1][col+1] == 'X')  // only check the square to the top-right if it's in bounds

Do likewise for the other 7 neighbors.

paranoidgnu,

I think Mike got a good one. I haven't personally gone over your code yet, but...

Originally Posted by mike65535

Code:

if (num_neighbors <= 3 || num_neighbors >= 2)

That line looks suspicious. Is it not true for all values of num_neighbors?

Suspicious is an understatement. The number line draws that the Algebra teacher has one do would demonstrate that is the entire number line, and thus always true. Let's see...

Code:

                                        =-------------------------------> (2nd)
                  <----------------------------= (1st)
<------------------------|-------|------|------|--------------------------------->
                         0              2      3 
1st Condition: n <= 3
2nd Condition: n >= 2

So no mater where num_neighbors is on the number line, the conditional statement is true.... I hope I didn't make that too difficult, but those sorts of correctness proofs come in handy when dealing with logic errors. Please do keep them in mind.

Best Regards,