Language: C++

#include<iostream> 
#include<iomanip> 
#include<vector> 
#include<map> 
#include<set> 
#include<algorithm> 
#include<numeric> 
#include<limits> 
#include<bitset> 
#include<functional> 
#include<type_traits> 
#include<queue> 
#include<stack> 
#include<array> 
#include<random> 
#include<utility> 
#include<cstdlib> 
#include<ctime>
#define INT_MAX 2147483647
#define _LIBCPP_DEBUG 0
#define _GLIBCXX_DEBUG
#define rep(i,n) for (int i = 0; i < (n); ++i)	
using namespace std;

int max(int a,int b) {
	int max;
	if (a > b) max = a;
	else max = b;
	return max;
}
int min(int a, int b) {
	int min;
	if (a < b) min = a;
	else min = b;
	return min;
}


int main() {
	int n;
	vector<int> a;
	cin >> n;
	rep(i, n) {
		cin >> a[i];
	}
	sort(a, a + n);
	reverse(a, a + n);

	int A = 0, B = 0;
	rep(i, n) {
		if (i % 2 == 0) {
			A += a[i];
		}
		else {
			B += a[i];
		 }
	}
	cout << A - B << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:46:19: error: no match for 'operator+' (operand types are 'std::vector<int>' and 'int')
   46 |         sort(a, a + n);
      |                 ~ ^ ~
      |                 |   |
      |                 |   int
      |                 std::vector<int>
In file included from /usr/include/c++/14/string:48,
                 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,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_iterator.h:627:5: note: candidate: 'template<class _Iterator> constexpr std::reverse_iterator<_Iterator> std::operator+(typename reverse_iterator<_Iterator>::difference_type, const reverse_iterator<_Iterator>&)'
  627 |     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:627:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'int'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note: candidate: 'template<class _Iterator> constexpr std::move_iterator<_IteratorL> std::operator+(typename move_iterator<_IteratorL>::difference_type, const move_iterator<_IteratorL>&)'
 1798 |     operator+(typename move_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'int'
   46 |         sort(a, a + n);
      |                     ^
In file included from /usr/include/c++/14/string:54:
/usr/include/c++/14/bits/basic_string.h:3598:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3598 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3598:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   'std::vector<int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3616:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3616 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3616:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   mismatched types 'const _CharT*' and 'std::vector<int>'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3635:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3635 |     operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Alloc>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3635:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3652:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3652 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3652:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   'std::vector<int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3670:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, _CharT)'
 3670 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3670:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   'std::vector<int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3682:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3682 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3682:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   'std::vector<int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3689:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3689 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3689:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   'std::vector<int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3696:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3696 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3696:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   'std::vector<int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3719:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3719 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3719:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   mismatched types 'const _CharT*' and 'std::vector<int>'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3726:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3726 |     operator+(_CharT __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3726:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3733:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const _CharT*)'
 3733 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3733:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   'std::vector<int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   46 |         sort(a, a + n);
      |                     ^
/usr/include/c++/14/bits/basic_string.h:3740:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, _CharT)'
 3740 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3740:5: note:   template argument deduction/substitution failed:
a.cc:46:21: note:   'std::vector<int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   46 |         sort(a, a + n);
      |                     ^
a.cc:47:22: error: no match for 'operator+' (operand types are 'std::vector<int>' and 'int')
   47 |         reverse(a, a + n);
      |                    ~ ^ ~
      |                    |   |
      |                    |   int
      |                    std::vector<int>
/usr/include/c++/14/bits/stl_iterator.h:627:5: note: candidate: 'template<class _Iterator> constexpr std::reverse_iterator<_Iterator> std::operator+(typename reverse_iterator<_Iterator>::difference_type, const reverse_iterator<_Iterator>&)'
  627 |     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:627:5: note:   template argumen