Eroare de compilare: main.cpp: In function 'void preorder(int)': main.cpp:45:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 45 | for (i = 0; i < v.size(); i++) | ~~^~~~~~~~~~ main.cpp:46:21: error: 'g' was not declared in this scope 46 | g << v[i] << " "; | ^ Non zero exit status: 1