Compilare: user.cpp: In function ‘void dfs(const std::vector<std::vector<int> >&, const int&, const int&, std::vector<bool>&, std::stack<int>&)’: user.cpp:18:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<graph[element].size() && !found;i++) ^ user.cpp: In function ‘int main()’: user.cpp:43:15: warning: unused variable ‘k’ [-Wunused-variable] int v,e,i,k,aux1,aux2; ^