Compilare: user.cpp: In function ‘int main()’: user.cpp:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<primes.size();i++) ~^~~~~~~~~~~~~~ user.cpp:44:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<ans.size();i++) printf("%d ",ans[i]); ~^~~~~~~~~~~ user.cpp:10:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divizori.in","r",stdin); ^ user.cpp:11:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divizori.out","w",stdout); ^ user.cpp:13:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^