Compilare: user.cpp: In function ‘std::vector<int> LIS()’: user.cpp:14:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1;i<ar.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:42:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<b.size()-1;i++) ^ user.cpp:30:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scmax.in","r",stdin); ^ user.cpp:31:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scmax.out","w",stdout); ^