Compilare: user.cpp: In function ‘void dfs()’: user.cpp:18:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[nod].size(); ++i) ~~^~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:45:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < v[i].size(); ++j) ~~^~~~~~~~~~~~~