Compilare: main.cpp: In function 'int main()': main.cpp:57:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<fn.size();i++)cout<<fn[i]<<endl; ~^~~~~~~~~~ main.cpp:27:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("text3.in","r",stdin); ^ main.cpp:28:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("text3.out","w",stdout); ^