Eroare de compilare: user.cpp: In function ‘int answer(int)’: user.cpp:30:13: error: reference to ‘prev’ is ambiguous prev[i].push_back(j); ^~~~ user.cpp:8:16: note: candidates are: std::vector<int> prev [4001] vector < int > prev[NMAX]; ^~~~ In file included from /usr/include/c++/6/bits/stl_algobase.h:66:0, from /usr/include/c++/6/bits/char_traits.h:39, from /usr/include/c++/6/ios:40, from /usr/include/c++/6/ostream:38, from /usr/include/c++/6/iostream:39, from user.cpp:1: /usr/include/c++/6/bits/stl_iterator_base_funcs.h:217:5: note: template<class _BidirectionalIterator> _BidirectionalIterator std::prev(_BidirectionalIterator, typename std::iterator_traits<_Iter>::difference_type) prev(_BidirectionalIterator __x, typename ^~~~ user.cpp: In function ‘int main()’: user.cpp:57:12: error: reference to ‘prev’ is ambiguous fout<<prev[indx].size()<<" "; ^~~~ user.cpp:8:16: note: candidates are: std::vector<int> prev [4001] vector < int > prev[NMAX]; ^~~~ In file included from /usr/include/c++/6/bits/stl_algobase.h:66:0, from /usr/include/c++/6/bits/char_traits.h:39, from /usr/include/c++/6/ios:40, from /usr/include/c++/6/ostream:38, from /usr/include/c++/6/iostream:39, from user.cpp:1: /usr/include/c++/6/bits/stl_iterator_base_funcs.h:217:5: note: template<class _BidirectionalIterator> _BidirectionalIterator std::prev(_BidirectionalIterator, typename std::iterator_traits<_Iter>::difference_type) prev(_BidirectionalIterator __x, typename ^~~~ user.cpp:59:26: error: reference to ‘prev’ is ambiguous for(int i = 0 ; i < prev[indx].size(); i++) ^~~~ user.cpp:8:16: note: candidates are: std::vector<int> prev [4001] vector < int > prev[NMAX]; ^~~~ In file included from /usr/include/c++/6/bits/stl_algobase.h:66:0, from /usr/include/c++/6/bits/char_traits.h:39, from /usr/include/c++/6/ios:40, from /usr/include/c++/6/ostream:38, from /usr/include/c++/6/iostream:39, from user.cpp:1: /usr/include/c++/6/bits/stl_iterator_base_funcs.h:217:5: note: template<class _BidirectionalIterator> _BidirectionalIterator std::prev(_BidirectionalIterator, typename std::iterator_traits<_Iter>::difference_type) prev(_BidirectionalIterator __x, typename ^~~~ user.cpp:60:15: error: reference to ‘prev’ is ambiguous fout<<prev[indx][i]<<'\n'; ^~~~