//void prob3(double ***A, double ***B, double **a, double **b)
void prob3(void)
{
  FILE *matrix;
  int k;
  double ***A, ***B, **a, **b;
  matrix=fopen("matrix.dat", "r");

  *A= (double**)malloc(sizeof(double*)*4);
  *B= (double**)malloc(sizeof(double*)*4);
  *a= (double*)malloc(sizeof(double)*4);
  *b= (double*)malloc(sizeof(double)*4);

  for(k=0; k<4; k++)
    {
     fscanf(matrix, "%lf %lf %lf %lf", &(*A)[k][0], &(*A)[k][1], &(*A)[k][2], &(*A)[k][3]);
    }
     for(k=0; k<4; k++)
       {
        fscanf(matrix, "%lf", &(*a)[k]);
       }
  matrix1(*A, *B, *a, *b, 4);


}

void problem3()
{
  double **A, **B, *a, *b;
  int row, col;

  printf("\nMatrix B is:\n\n");
  for(row=0; row<4; row++)
     {
      for(col=0; col<4; col++)
        {
         printf("%.3f  ", B[row][col]);
        }
     }
  printf("\nVector b is: \n\n");
  printf("a[] = ");
  for(col=0; col<4; col++)
    {
     printf("%.3f  ", b[col]);
    }
  for(row=0; row<4; row++)
    {
     free(A[row]);
     free(B[row]);
    }

  free(A);
  free(B);
  free(a);
  free(b);
}

    /* suppose we want an array of int: a[5][3] */
    int **a;
    num_rows = 5;
    num_cols = 3;

    /*  allocate storage for an array of pointers */
    a = malloc(num_rows * sizeof(int *));
    if (a == NULL) {
        printf("Can't allocate %d bytes for a\n", num_rows * sizeof(int *));
        return 1;
    }

    /* for each pointer, allocate storage for an array of ints */
    for (i = 0; i < num_rows; i++) {
        a[i] = malloc(num_cols * sizeof(int));
        if (a[i] == NULL) {
            printf("Can't allocate %d bytes for a[%d]\n", i,
                   num_cols * sizeof(int));
            for (j = 0; j < i; j++) {
                free(a[j]);
            }
            free(a);
            return 1;
        }
    }