Compilare: user.cpp: In function ‘void DFS(int, std::vector<int>&)’: user.cpp:16:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (auto i = 0; i < A[nod].size(); i++) ~~^~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:119:48: warning: ‘second’ may be used uninitialized in this function [-Wmaybe-uninitialized] out << rez << ' ' << first << ' ' << second; ^ user.cpp:119:35: warning: ‘first’ may be used uninitialized in this function [-Wmaybe-uninitialized] out << rez << ' ' << first << ' ' << second; ^~~