Compilare: user.cpp: In function ‘int main()’: user.cpp:20:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&n); ^ user.cpp:22:59: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&oras[i].first,&oras[i].second); ^ user.cpp:46:70: warning: ‘nod’ may be used uninitialized in this function [-Wmaybe-uninitialized] for (vector <pair <int,double> > :: iterator it=v[nod].begin() ; it!=v[nod].end() ; it++){ ^