Two-Dimensional cellular automaton

/*
 * Made by: Vinicius Arruda
 * E-mail: vinicius_farruda@hotmail.com
 * Blog: csvacation.wordpress.com
 */

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

#ifdef _WIN32
    #define CLEAR "cls"
#else
    #define CLEAR "clear"
#endif

int TAM;

/* Prints the grid */
void imprime(char** board)
{
    int i, j;
    for(i=0;i<TAM;i++)
    {
        printf("\n");
        for(j=0;j<TAM;j++)
        {
            printf(" %c", board[i][j]);
        }
    }
    printf("\n\n");
}


int limite(int x, int b)
{
    if(b)
        if(x==(TAM-1))
            return 0;
        else
            return x+1;
    else
        if(x==0)
            return (TAM-1);
        else
            return x-1;
}


int conta_vivo(char** board, int i, int j)
{
    int vivo = 0;

    if(board[limite(i,0)][limite(j,0)] == '0' || board[limite(i,0)][limite(j,0)] == '2')
        vivo++;
    if(board[limite(i,0)][j] == '0' || board[limite(i,0)][j] == '2')
        vivo++;
    if(board[limite(i,0)][limite(j,1)] == '0' || board[limite(i,0)][limite(j,1)] == '2')
        vivo++;
    if(board[i][limite(j,0)] == '0' || board[i][limite(j,0)] == '2')
        vivo++;
    if(board[i][limite(j,1)] == '0' || board[i][limite(j,1)] == '2')
        vivo++;
    if(board[limite(i,1)][limite(j,0)] == '0' || board[limite(i,1)][limite(j,0)] == '2')
        vivo++;
    if(board[limite(i,1)][j] == '0' || board[limite(i,1)][j] == '2')
        vivo++;
    if(board[limite(i,1)][limite(j,1)] == '0' || board[limite(i,1)][limite(j,1)] == '2')
        vivo++;

    return vivo;
}


void nasce(char** board, int i, int j, int *f)
{
    if(conta_vivo(board, i, j) == 3)
    {
        board[i][j] = '3';
        *f = 1;
    }
}


void morre(char** board, int i, int j, int *f)
{
    if(conta_vivo(board, i, j)<2 || conta_vivo(board, i, j)>3)
    {
        board[i][j] = '2';
        *f = 1;
    }
}


void atualiza(char** board)
{
    int i, j;
    for(i=0; i<TAM; i++)
        for(j=0;j<TAM;j++)
        {
            if(board[i][j] == '2')
                board[i][j] = '-';
            if(board[i][j] == '3')
                board[i][j] = '0';
        }
}


void pausa(void)
{
    int i;
    for(i=0;i<100000000;i++);

}


int arquivo(char** board, char *file)
{
    int i, j;
    FILE *arquiv;

    if( (arquiv = fopen(file, "r") ) == NULL)
    {
        printf("Error opening the file !\n");
        return(1);
    }


    for(i=0; i<TAM; i++)
    {
        for(j=0; j<TAM; j++)
            board[i][j] = (char) getc(arquiv);
        getc(arquiv);
    }

    fclose(arquiv);
    return 0;
}



int main(int argc, char **argv)
{
    int i, j, flag;
    char** board;

    if(argc < 3)
    {
        printf("Usage: ./%s NameOfFileStartGrid.txt GridDimension.\n", argv[0]);
        return(1);
    }

    TAM = atoi(argv[2]);

    board = malloc((unsigned int) TAM * sizeof(char*));
    for(i = 0; i < TAM; i++)
        board[i] = malloc((unsigned int) TAM * sizeof(char));

    arquivo(board, argv[1]);

    flag = 1;

    while(flag==1)
    {
        pausa();

        system(CLEAR);

        imprime(board);

        flag = 0;

        for(i=0; i<TAM; i++)
            for(j=0;j<TAM;j++)
            {
                if(board[i][j] == '-')
                    nasce(board, i, j, &flag);
                else if(board[i][j] == '0')
                    morre(board, i, j, &flag);
            }
        atualiza(board);
    }
    free(board);

    return 0;
}