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

#define   N      9                                /* in the interval [-N, N] */
#define   NCOL   10                                        /* number of cols */

typedef   double **   matrix;
typedef   double *    row;
typedef   double      elem;

void     fill_matrix(matrix a, int m, int n);
matrix   get_matrix_space(int m, int n);
void *   gmalloc(size_t n);
void     prn_info(const char *pgm_name);
void     prn_matrix(char *mtrx_name, matrix a, int m, int n, FILE *ofp);
void     release_matrix_space(matrix a);
elem     trace(matrix a, int m, int n);