Compilare: user.cpp: In function ‘int main()’: user.cpp:6:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] int main(){freopen("granita.in","r",stdin);freopen("granita.out","w",stdout); ^ user.cpp:6:77: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] int main(){freopen("granita.in","r",stdin);freopen("granita.out","w",stdout); ^ user.cpp:7:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:8:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1;i<=N;i++)scanf("%d%d",&v[i].x,&v[i].y); ^