Eroare de compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:10:22: error: request for member ‘size’ in ‘gr.std::vector<_Tp, _Alloc>::operator[]<int, std::allocator<int> >(((std::vector<int>::size_type)u))’, which is of non-class type ‘__gnu_cxx::__alloc_traits<std::allocator<int> >::value_type {aka int}’ for(i=0; i<gr[u].size(); i++) { ^ user.cpp:11:22: error: invalid types ‘__gnu_cxx::__alloc_traits<std::allocator<int> >::value_type {aka int}[int]’ for array subscript if(!a[gr[u][i]]) { ^ user.cpp:12:24: error: invalid types ‘__gnu_cxx::__alloc_traits<std::allocator<int> >::value_type {aka int}[int]’ for array subscript dfs(gr[u][i]); ^ user.cpp: In function ‘int main()’: user.cpp:22:10: error: no match for ‘operator[]’ (operand types are ‘std::ofstream {aka std::basic_ofstream<char>}’ and ‘int’) g[a].pushback(b); ^ user.cpp:23:10: error: no match for ‘operator[]’ (operand types are ‘std::ofstream {aka std::basic_ofstream<char>}’ and ‘int’) g[b].pushback(a); ^