dynamic allocating array of arrays in C

Question

I don\'t truly understand some basic things in C like dynamically allocating array of arrays. I know you can do:

int **m;

in order to decla

Answer 1

Humm. How about old fashion smoke and mirrors as an option?

#define ROWS  5
#define COLS 13
#define X(R, C) *(p + ((R) * ROWS) + (C))

int main(void)
{
    int *p = (int *) malloc (ROWS * COLS * sizeof(int));
    if (p != NULL)
    {
        size_t r;
        size_t c;
        for (r = 0; r < ROWS; r++)
        {
            for (c = 0; c < COLS; c++)
            {
                 X(r,c) = r * c;  /* put some silly value in that position */ 
            }
        }

        /* Then show the contents of the array */ 
        for (r = 0; r < ROWS; r++)
        {
            printf("%d ", r);   /* Show the row number */ 

            for (c = 0; c < COLS; c++)
            {
                 printf("%d", X(r,c));
            }

            printf("\n");
        }

        free(p);
    }
    else
    {
        /* issue some silly error message */ 
    }

    return 0;
}