festival.cpp: In function 'std::vector<int> max_coupons(int, std::vector<int>, std::vector<int>)':
festival.cpp:48:48: error: no matching function for call to 'std::vector<int>::push_back(__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 3> >, std::array<int, 3> >::value_type&)'
48 | a = (a - v[i][0]) * v[i][1]; ans.pb(v[2]);
| ~~~~~~^~~~~~
In file included from /usr/include/c++/11/vector:67,
from festival.h:1,
from festival.cpp:1:
/usr/include/c++/11/bits/stl_vector.h:1187:7: note: candidate: 'void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = int; _Alloc = std::allocator<int>; std::vector<_Tp, _Alloc>::value_type = int]'
1187 | push_back(const value_type& __x)
| ^~~~~~~~~
/usr/include/c++/11/bits/stl_vector.h:1187:35: note: no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 3> >, std::array<int, 3> >::value_type' {aka 'std::array<int, 3>'} to 'const value_type&' {aka 'const int&'}
1187 | push_back(const value_type& __x)
| ~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/11/bits/stl_vector.h:1203:7: note: candidate: 'void std::vector<_Tp, _Alloc>::push_back(std::vector<_Tp, _Alloc>::value_type&&) [with _Tp = int; _Alloc = std::allocator<int>; std::vector<_Tp, _Alloc>::value_type = int]'
1203 | push_back(value_type&& __x)
| ^~~~~~~~~
/usr/include/c++/11/bits/stl_vector.h:1203:30: note: no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 3> >, std::array<int, 3> >::value_type' {aka 'std::array<int, 3>'} to 'std::vector<int>::value_type&&' {aka 'int&&'}
1203 | push_back(value_type&& __x)
| ~~~~~~~~~~~~~^~~