Compilare: main.cpp: In function 'std::vector<int> rank_cats(std::vector<int>, std::vector<int>, std::vector<int>)': main.cpp:196:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(top_ord.size() < n) ~~~~~~~~~~~~~~~^~~ main.cpp: In member function 'char InParser::read_ch()': main.cpp:23:29: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, fin); ^