Compilare: main.cpp: In member function 'void solution::reset()': main.cpp:87:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<g.size();++i){ ~^~~~~~~~~ main.cpp: In member function 'void solution::solve()': main.cpp:211:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<path.size();++i){ ~^~~~~~~~~~~~ main.cpp: In member function 'char InParser::read_ch()': main.cpp:17:29: 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); ^