Compilare: main.cpp: In member function 'bool Graph::havelHakim(std::vector<int>)': main.cpp:147:18: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 147 | if(grades[0] > grades.size()-1)