Compilare: user.cpp: In member function ‘void Solver::Solve()’: user.cpp:202:10: warning: unused variable ‘first’ [-Wunused-variable] int first = groupStack[size - 2].last; ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:14:29: 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); ^