molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:18:14: error: '__gnu_cxx::__alloc_traits<std::allocator<std::pair<int, int> > >::value_type {aka struct std::pair<int, int>}' has no member named 'x'
sum+=ww[r].x;
^
molecules.cpp:21:14: error: request for member 'x' in 'w.std::vector<int>::operator[](((std::vector<int>::size_type)a))', which is of non-class type '__gnu_cxx::__alloc_traits<std::allocator<int> >::value_type {aka int}'
sum-=w[a].x;
^
molecules.cpp:26:25: error: '__gnu_cxx::__alloc_traits<std::allocator<std::pair<int, int> > >::value_type {aka struct std::pair<int, int>}' has no member named 'y'
ans.push_back(ww[i].y);
^