Eroare de compilare: user.cpp: In member function ‘Cuckoo& Cuckoo::operator-(int)’: user.cpp:123: error: lvalue required as unary ‘&’ operand user.cpp: In function ‘int main()’: user.cpp:129: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:130: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:133: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:136: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result