Compilare: user.cpp: In function ‘int main()’: user.cpp:31:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<an[-*it].size();i++) ^ user.cpp:44:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<ap[*it].size();i++) ^ user.cpp:16:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in","r",stdin); ^ user.cpp:17:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out","w",stdout); ^