answer.code:42:10: error: reference to ‘data’ is ambiguous
   42 | bool cmp(data a, data b) {
      |          ^~~~
In file included from /usr/include/c++/11/string:54,
                 from /usr/include/c++/11/bits/locale_classes.h:40,
                 from /usr/include/c++/11/bits/ios_base.h:41,
                 from /usr/include/c++/11/ios:42,
                 from /usr/include/c++/11/ostream:38,
                 from /usr/include/c++/11/iostream:39,
                 from answer.code:1:
/usr/include/c++/11/bits/range_access.h:319:5: note: candidates are: ‘template<class _Tp> constexpr const _Tp* std::data(std::initializer_list<_Tp>)’
  319 |     data(initializer_list<_Tp> __il) noexcept
      |     ^~~~
/usr/include/c++/11/bits/range_access.h:310:5: note:                 ‘template<class _Tp, long unsigned int _Nm> constexpr _Tp* std::data(_Tp (&)[_Nm])’
  310 |     data(_Tp (&__array)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/11/bits/range_access.h:300:5: note:                 ‘template<class _Container> constexpr decltype (__cont.data()) std::data(const _Container&)’
  300 |     data(const _Container& __cont) noexcept(noexcept(__cont.data()))
      |     ^~~~
/usr/include/c++/11/bits/range_access.h:290:5: note:                 ‘template<class _Container> constexpr decltype (__cont.data()) std::data(_Container&)’
  290 |     data(_Container& __cont) noexcept(noexcept(__cont.data()))
      |     ^~~~
answer.code:9:8: note:                 ‘struct data’
    9 | struct data{
      |        ^~~~
answer.code:42:18: error: reference to ‘data’ is ambiguous
   42 | bool cmp(data a, data b) {
      |                  ^~~~
In file included from /usr/include/c++/11/string:54,
                 from /usr/include/c++/11/bits/locale_classes.h:40,
                 from /usr/include/c++/11/bits/ios_base.h:41,
                 from /usr/include/c++/11/ios:42,
                 from /usr/include/c++/11/ostream:38,
                 from /usr/include/c++/11/iostream:39,
                 from answer.code:1:
/usr/include/c++/11/bits/range_access.h:319:5: note: candidates are: ‘template<class _Tp> constexpr const _Tp* std::data(std::initializer_list<_Tp>)’
  319 |     data(initializer_list<_Tp> __il) noexcept
      |     ^~~~
/usr/include/c++/11/bits/range_access.h:310:5: note:                 ‘template<class _Tp, long unsigned int _Nm> constexpr _Tp* std::data(_Tp (&)[_Nm])’
  310 |     data(_Tp (&__array)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/11/bits/range_access.h:300:5: note:                 ‘template<class _Container> constexpr decltype (__cont.data()) std::data(const _Container&)’
  300 |     data(const _Container& __cont) noexcept(noexcept(__cont.data()))
      |     ^~~~
/usr/include/c++/11/bits/range_access.h:290:5: note:                 ‘template<class _Container> constexpr decltype (__cont.data()) std::data(_Container&)’
  290 |     data(_Container& __cont) noexcept(noexcept(__cont.data()))
      |     ^~~~
answer.code:9:8: note:                 ‘struct data’
    9 | struct data{
      |        ^~~~
answer.code:42:24: error: expression list treated as compound expression in initializer [-fpermissive]
   42 | bool cmp(data a, data b) {
      |                        ^
answer.code: In function ‘int main()’:
answer.code:50:5: error: ‘sort’ was not declared in this scope; did you mean ‘short’?
   50 |     sort(p+1, p+1+n, cmp);
      |     ^~~~
      |     short