/in/foo.cc:7:20: error: 'studebt' has not been declared
    7 | bool cmp(student x,studebt y){
      |                    ^~~~~~~
/in/foo.cc: In function 'bool cmp(student, int)':
/in/foo.cc:8:19: error: 'b' was not declared in this scope
    8 |         if(x.b==y[b]) return x.c>y.c;
      |                   ^
/in/foo.cc:8:36: error: request for member 'c' in 'y', which is of non-class type 'int'
    8 |         if(x.b==y[b]) return x.c>y.c;
      |                                    ^
/in/foo.cc:9:22: error: request for member 'b' in 'y', which is of non-class type 'int'
    9 |         return x.b>y.b;
      |                      ^
In file included from /usr/include/c++/12/bits/stl_algobase.h:71,
                 from /usr/include/c++/12/string:50,
                 from /usr/include/c++/12/bits/locale_classes.h:40,
                 from /usr/include/c++/12/bits/ios_base.h:41,
                 from /usr/include/c++/12/ios:42,
                 from /usr/include/c++/12/istream:38,
                 from /usr/include/c++/12/sstream:38,
                 from /usr/include/c++/12/complex:45,
                 from /usr/include/c++/12/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/12/bits/stdc++.h:54,
                 from /in/foo.cc:1:
/usr/include/c++/12/bits/predefined_ops.h: In instantiation of 'bool __gnu_cxx::__ops::_Iter_comp_iter<_Compare>::operator()(_Iterator1, _Iterator2) [with _Iterator1 = student*; _Iterator2 = student*; _Compare = bool (*)(student, int)]':
/usr/include/c++/12/bits/stl_algo.h:1809:14:   required from 'void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:1849:25:   required from 'void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:1940:31:   required from 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:4853:18:   required from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = student*; _Compare = bool (*)(student, int)]'
/in/foo.cc:14:6:   required from here
/usr/include/c++/12/bits/predefined_ops.h:158:30: error: cannot convert 'student' to 'int' in argument passing
  158 |         { return bool(_M_comp(*__it1, *__it2)); }
      |                       ~~~~~~~^~~~~~~~~~~~~~~~
/usr/include/c++/12/bits/predefined_ops.h: In instantiation of 'bool __gnu_cxx::__ops::_Val_comp_iter<_Compare>::operator()(_Value&, _Iterator) [with _Value = student; _Iterator = student*; _Compare = bool (*)(student, int)]':
/usr/include/c++/12/bits/stl_algo.h:1789:20:   required from 'void std::__unguarded_linear_insert(_RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Val_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:1817:36:   required from 'void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:1849:25:   required from 'void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:1940:31:   required from 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:4853:18:   required from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = student*; _Compare = bool (*)(student, int)]'
/in/foo.cc:14:6:   required from here
/usr/include/c++/12/bits/predefined_ops.h:240:30: error: cannot convert 'student' to 'int' in argument passing
  240 |         { return bool(_M_comp(__val, *__it)); }
      |                       ~~~~~~~^~~~~~~~~~~~~~
/usr/include/c++/12/bits/predefined_ops.h: In instantiation of 'bool __gnu_cxx::__ops::_Iter_comp_val<_Compare>::operator()(_Iterator, _Value&) [with _Iterator = student*; _Value = student; _Compare = bool (*)(student, int)]':
/usr/include/c++/12/bits/stl_heap.h:140:48:   required from 'void std::__push_heap(_RandomAccessIterator, _Distance, _Distance, _Tp, _Compare&) [with _RandomAccessIterator = student*; _Distance = long int; _Tp = student; _Compare = __gnu_cxx::__ops::_Iter_comp_val<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_heap.h:247:23:   required from 'void std::__adjust_heap(_RandomAccessIterator, _Distance, _Distance, _Tp, _Compare) [with _RandomAccessIterator = student*; _Distance = long int; _Tp = student; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_heap.h:356:22:   required from 'void std::__make_heap(_RandomAccessIterator, _RandomAccessIterator, _Compare&) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:1629:23:   required from 'void std::__heap_select(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:1900:25:   required from 'void std::__partial_sort(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:1916:27:   required from 'void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = student*; _Size = long int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:1937:25:   required from 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = student*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<bool (*)(student, int)>]'
/usr/include/c++/12/bits/stl_algo.h:4853:18:   required from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = student*; _Compare = bool (*)(student, int)]'
/in/foo.cc:14:6:   required from here
/usr/include/c++/12/bits/predefined_ops.h:196:30: error: cannot convert 'student' to 'int' in argument passing
  196 |         { return bool(_M_comp(*__it, __val)); }
      |                       ~~~~~~~^~~~~~~~~~~~~~