Compilare: user.cpp: In member function ‘void graph::dfsutil(int, bool*)’: user.cpp:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[k].size();i++) ^ user.cpp: In member function ‘void graph::dfsutil2(int, bool*)’: user.cpp:40:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[k].size();i++) ^ user.cpp: In member function ‘void graph::dfs(int, bool*)’: user.cpp:46:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[k].size();i++) ^ user.cpp: In member function ‘graph graph::ogl()’: user.cpp:56:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[i].size();j++) ^