Compilare: user.cpp: In function ‘int DFS(int)’: user.cpp:19:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[u].size(); ++i){ ^ user.cpp:29:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:45:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < l[i].size(); ++j) ^