Compilare: user.cpp: In member function 'int Graph::Dfs(int)': user.cpp:28: warning: comparison between signed and unsigned integer expressions user.cpp:35: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int main()': user.cpp:68: warning: unused variable 'threads' user.cpp: In function 'void* Df(void*)': user.cpp:49: warning: control reaches end of non-void function