Compilare: user.cpp: In function ‘int ok(int)’: user.cpp:107:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<R[1].size(); i++) ^ user.cpp:108:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1; j<R[2].size(); j++) ^ user.cpp:113:17: warning: unused variable ‘x’ [-Wunused-variable] int x=aux.first,y=aux.second; ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:21:38: 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); ^