Compilare: user.cpp: In function ‘int dfs(int, int)’: user.cpp:14:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<L[x].size();i++) ^ user.cpp:19:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:34:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<F[i].size();j++) ^