Compilare: user.cpp: In function ‘int main()’: user.cpp:36:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f1,"%d %d",&n,&m); ^ user.cpp:37:51: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1;i<=m;i++) {fscanf(f1,"%d %d %d",&u,&v,&c);a[u].push_back(v);a[v].push_back(u);C[u][v]=c;} ^