Compilare: main.cpp: In member function 'virtual Card& Card::operator=(const Card&)': main.cpp:139:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Bilet*>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 139 | for (int i = 0; i < this->b.size(); i++) | ~~^~~~~~~~~~~~~~~~ main.cpp:144:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Bilet*>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 144 | for (int i = 0; i < c.b.size(); i++) | ~~^~~~~~~~~~~~ main.cpp: In destructor 'virtual Card::~Card()': main.cpp:163:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Bilet*>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 163 | for (int i = 0; i < b.size(); i++) | ~~^~~~~~~~~~ main.cpp: In member function 'virtual std::ostream& CardSuprafata::afisare(std::ostream&) const': main.cpp:219:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Bilet*>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 219 | for (int i = 0; i < b.size(); i++) | ~~^~~~~~~~~~ main.cpp: In member function 'virtual std::ostream& CardMetrou::afisare(std::ostream&) const': main.cpp:306:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Bilet*>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 306 | for (int i = 0; i < b.size(); i++) | ~~^~~~~~~~~~ main.cpp: In member function 'virtual std::ostream& CardTranzitie::afisare(std::ostream&) const': main.cpp:371:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Bilet*>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 371 | for (int i = 0; i < b.size(); i++) | ~~^~~~~~~~~~ main.cpp: In member function 'virtual Carduri& Carduri::operator=(const Carduri&)': main.cpp:444:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Card*>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 444 | for (int i = 0; i < this->c.size(); i++) | ~~^~~~~~~~~~~~~~~~ main.cpp:449:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Card*>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 449 | for (int i = 0; i < c.c.size(); i++) | ~~^~~~~~~~~~~~ main.cpp: In destructor 'virtual Carduri::~Carduri()': main.cpp:468:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Card*>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 468 | for (int i = 0; i < c.size(); i++) | ~~^~~~~~~~~~