Compilare: user.cpp: In function ‘int main()’: user.cpp:60:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; step < _dfs[i].size() && _dfs[pas][step] == _dfs[i][step]; ++step); ^ user.cpp:62:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (step == _dfs[i].size()) ^ user.cpp:65:21: warning: unused variable ‘aux’ [-Wunused-variable] int aux = _dfs[pas][step]; ^