Compilare: user.cpp: In function ‘void dfs(int, int, int)’: user.cpp:17:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[s].size();++i) { ^ user.cpp: In function ‘int main()’: user.cpp:58:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=1;j<L[i].size();++j) ^