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

#define N 4
#define M 6

int main(void) {
  int *pint, i, j;

  // Allocate space for a N x M matrix:
  pint = (int *)malloc(N*M*sizeof(int));

  if (pint == NULL){
     printf("Cannot allocate enough memory. Bye");
     exit(EXIT_FAILURE);
  }

  // Initialize the matrix:
  for (i=0; i<N; i++)
   for (j=0; j<M; j++)
     *(pint + M*i + j) = (i+1) * (j+1);

  // Print the matrix nicely:
  for (i = 0; i < M * N; i++){
    printf("%4i ", *(pint + i));
    if ((i+1) % M == 0) printf("\n");
  }

  // Free the space:
  free(pint);

  return 0;
}