Language: C++

#include <iostream>
#include <algorithm>
using namespace std;

int main(){
  
  //入力
  int N;
  cin >> N;
  int a[110];
  for( int i = 0; i < N; i++ )cin >> a[i];
  
  //処理
  sort(a[0], a[N-1],greater<int>());
      int score_Alice = 0;
    int score_Bob = 0;
  for( int i = 0; i < N-1; i++ ){
    
    if( i % 2 == 0 )score_Alice += a[i];
    if( i % 2 != 0 )score_Bob += a[i];
    
  }
  
  //出力
  cout << score_Alice - score_Bob << endl;
  
}


Compiler output:
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_algo.h: In instantiation of 'void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]':
/usr/include/c++/14/bits/stl_algo.h:1817:25:   required from 'void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1817 |           std::__insertion_sort(__first, __first + int(_S_threshold), __comp);
      |           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1908:31:   required from 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1908 |           std::__final_insertion_sort(__first, __last, __comp);
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4805:18:   required from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = int; _Compare = greater<int>]'
 4805 |       std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
      |       ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:14:7:   required from here
   14 |   sort(a[0], a[N-1],greater<int>());
      |   ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1780:17: error: no type named 'value_type' in 'struct std::iterator_traits<int>'
 1780 |                 __val = _GLIBCXX_MOVE(*__i);
      |                 ^~~~~
In file included from /usr/include/c++/14/bits/exception_ptr.h:41,
                 from /usr/include/c++/14/exception:166,
                 from /usr/include/c++/14/ios:41,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algo.h:1780:25: error: invalid type argument of unary '*' (have 'int')
 1780 |                 __val = _GLIBCXX_MOVE(*__i);
      |                         ^~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1782:15: error: invalid type argument of unary '*' (have 'int')
 1782 |               *__first = _GLIBCXX_MOVE(__val);
      |               ^~~~~~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:71,
                 from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/bits/predefined_ops.h: In instantiation of 'constexpr bool __gnu_cxx::__ops::_Iter_comp_iter<_Compare>::operator()(_Iterator1, _Iterator2) [with _Iterator1 = int; _Iterator2 = int; _Compare = std::greater<int>]':
/usr/include/c++/14/bits/stl_algo.h:1777:14:   required from 'void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1777 |           if (__comp(__i, __first))
      |               ~~~~~~^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1817:25:   required from 'void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1817 |           std::__insertion_sort(__first, __first + int(_S_threshold), __comp);
      |           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1908:31:   required from 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1908 |           std::__final_insertion_sort(__first, __last, __comp);
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4805:18:   required from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = int; _Compare = greater<int>]'
 4805 |       std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
      |       ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:14:7:   required from here
   14 |   sort(a[0], a[N-1],greater<int>());
      |   ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/predefined_ops.h:158:31: error: invalid type argument of unary '*' (have 'int')
  158 |         { return bool(_M_comp(*__it1, *__it2)); }
      |                               ^~~~~~
/usr/include/c++/14/bits/predefined_ops.h:158:39: error: invalid type argument of unary '*' (have 'int')
  158 |         { return bool(_M_comp(*__it1, *__it2)); }
      |                                       ^~~~~~
In file included from /usr/include/c++/14/bits/stl_algo.h:61:
/usr/include/c++/14/bits/stl_heap.h: In instantiation of 'void std::__make_heap(_RandomAccessIterator, _RandomAccessIterator, _Compare&) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]':
/usr/include/c++/14/bits/stl_algo.h:1593:23:   required from 'void std::__heap_select(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1593 |       std::__make_heap(__first, __middle, __comp);
      |       ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1868:25:   required from 'void std::__partial_sort(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1868 |       std::__heap_select(__first, __middle, __last, __comp);
      |       ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1884:27:   required from 'void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = int; _Size = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1884 |               std::__partial_sort(__first, __last, __last, __comp);
      |               ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1905:25:   required from 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1905 |           std::__introsort_loop(__first, __last,
      |           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
 1906 |                                 std::__lg(__last - __first) * 2,
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1907 |                                 __comp);
      |                                 ~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4805:18:   required from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = int; _Compare = greater<int>]'
 4805 |       std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
      |       ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:14:7:   required from here
   14 |   sort(a[0], a[N-1],greater<int>());
      |   ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_heap.h:344:11: error: no type named 'value_type' in 'struct std::iterator_traits<int>'
  344 |           _ValueType;
      |           ^~~~~~~~~~
/usr/include/c++/14/bits/stl_heap.h:346:11: error: no type named 'difference_type' in 'struct std::iterator_traits<int>'
  346 |           _DistanceType;
      |           ^~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_heap.h: In instantiation of 'void std::__pop_heap(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare&) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]':
/usr/include/c++/14/bits/stl_algo.h:1596:19:   required from 'void std::__heap_select(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1596 |           std::__pop_heap(__first, __middle, __i, __comp);
      |           ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1868:25:   required from 'void std::__partial_sort(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1868 |       std::__heap_select(__first, __middle, __last, __comp);
      |       ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1884:27:   required from 'void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = int; _Size = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1884 |               std::__partial_sort(__first, __last, __last, __comp);
      |               ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1905:25:   required from 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<greater<int> >]'
 1905 |           std::__introsort_loop(__first, __last,
      |           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
 1906 |                                 std::__lg(__last - __first) * 2,
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1907 |                                 __comp);
      |                                 ~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4805:18:   required from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = int; _Compare = greater<int>]'
 4805 |       std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
      |       ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~