Reading Sparse Matrix from Binary File in C - c

Question

Firstly, I am sorry for my English.
I am trying to read an integer array which represents some sparse matrix from a binary and I have to print this matrix.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 20
//on this way i have written the matrix in the binary
typedef struct{
int lin,col;
double val;
}termen;
typedef struct{
int nl,nc,nn;
termen* term;
}sparse_matrix;
void afisare_mat(sparse_matrix m){
int i,j,k = 0;
for(i = 0; i < m.nl; i++){
for(j = 0; j < m.nc; j++){
if(i == m.term[k].lin && j == m.term[k].col){
printf("%3.2lf ",m.term[k].val);
k++;
}else{
printf("%d ",0);
}
}printf("\n");
}
}
int main(){
/*this is the code used for write in the binary file
//i tried to print these values and seems to be ok
sparse_matrix m1,m2,m3;
m1.term = malloc(2*sizeof(termen));
m1.nl = 3;
m1.nc = 3;
m1.nn = 2;
m1.term[0].lin = 0;
m1.term[0].col = 1;
m1.term[0].val = 3.2;
m1.term[1].lin = 1;
m1.term[1].col = 2;
m1.term[1].val = 5.6;
afisare_mat(m1);
m2.term = malloc(3*sizeof(termen));
m2.nl = 4;
m2.nc = 4;
m2.nn = 3;
m2.term[0].lin = 0;
m2.term[0].col = 0;
m2.term[0].val = 1.9;
m2.term[1].lin = 1;
m2.term[1].col = 2;
m2.term[1].val = 0.5;
m2.term[2].lin = 2;
m2.term[2].col = 3;
m2.term[2].val = 6.960;
afisare_mat(m2);
m3.term = malloc(1*sizeof(termen));
m3.nl = 3;
m3.nc = 3;
m3.nn = 1;
m3.term[0].lin = 1;
m3.term[0].col = 2;
m3.term[0].val = 6.75;7
afisare_mat(m3);
FILE *f = fopen("in.bin","wb");
fwrite(&m1,sizeof(sparse_matrix),1,f);
fwrite(&m2,sizeof(sparse_matrix),1,f);
fwrite(&m3,sizeof(sparse_matrix),1,f);
fclose(f);
*/
FILE *f = fopen("in.bin","rb");
int n, v[10], i, j, k,nr = 0,it; //n=number of matrix asked, v=array with
//number(s)(<= n) of matrix which have to print
scanf("%d",&n);
sparse_matrix m;
while(fread(&k,sizeof(int),1,f) > 0){
fseek(f,2*sizeof(int),SEEK_CUR);
fseek(f,sizeof(termen*),SEEK_CUR);
nr++;
}
for(i = 0; i < n; i++){
scanf("%d",&v[i]);
if(v[i] > nr)
printf("That matrix not exist\n");
}
fseek(f,0,0);
j = 0;
while(fread(&k,sizeof(int),1,f) > 0){ //citesc nl din fiecare matrice
for(i = 0; i < n; i++){
if(j == v[i]){ //number of matrix which i read;
//print matrix
m.nl = k;
fread(&m.nc,sizeof(int),1,f);
fread(&m.nn,sizeof(int),1,f);
m.term = malloc(m.nn*sizeof(termen));
fread(m.term,sizeof(termen),m.nn,f);
afisare_mat(m);
free(m.term);
fseek(f,(j+1)*sizeof(sparse_matrix),0);
}
}j++;
}
fclose(f);
return 0;
}
This code prints on my screen the form of matrix but full of zeroes. I think that the rest of the elements (!= 0) aren't read ok from the binary file. Can you help me, please?