Compilare: user.cpp: In function ‘void dfs(int, int*, std::vector<int>*, bool)’: user.cpp:44:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<LA[u].size(); ++i) { ^ user.cpp: In function ‘void solve()’: user.cpp:68:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<LA[u].size(); ++i) { ^ user.cpp:101:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<LAC[u].size(); ++i) { ^ user.cpp:112:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<sol.size(); ++i) printf("%d %d\n", sol[i].first, sol[i].second); ^ user.cpp:108:47: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] sol.push_back(make_pair(asoc[last], asoc[st])); ^