Compilare: user.cpp: In function ‘int main()’: user.cpp:64:13: warning: unused variable ‘y’ [-Wunused-variable] int y=v[D.front()]; ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:18:38: 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); ^