C Programming

At this point, complex programs can be splitted into reusable/shared "libraries":

Header (structures and programs declarations):

// cells.h

#define DIM 2 

typedef char* CELLS;

CELLS create();
void  play (CELLS cells, char c, int p);
void  play2(CELLS cells, char c, int line, int col);
void  print(CELLS cells);

Implementation:

// cells.c
#include "cells.h"

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

CELLS create() {
  char* cells = malloc(DIM*DIM); 
  for (int p=0; p<DIM*DIM; p++)
    *(cells+p) = ' ';           
  return cells;                
}

void play(CELLS cells, char c, int p) {
  *(cells+p) = c; // OR: cells[p] = c;
}

void play2(CELLS cells, char c, int line, int col) {
  play(cells,c,DIM*line+col);
}

void print(CELLS cells) {
  for (int p=0; p<DIM*DIM; p++) {
    printf("%c",cells[p]);
    if (((p+1)%DIM)==0) printf("\n");
  }
}

Sample use:

// sample.c
// Usage: gcc cells.c sample.c -o sample.exe && ./sample.exe

#include "cells.h" 

void main() {
  CELLS cells = create();
  play2(cells,'X',0,1);
  print(cells);
}