Language: C++

#include <bits/stdc++.h>
using namespace std;
 
int main () {
  int N;
  cin >> N;
  long long sum = 0;
  vector<int> A(N);
  for (int i=0; i<N; i++) {
    cin >> A[i];
    sum += A[i];
  }
  sort(A.begin(),A.end());
  int Q;
  cin >> Q;
  
  vector<vector<int>> data(Q, vector<int>(2));
  for (int i = 0; i < Q; i++) {
    for (int j = 0; j < 2; j++) {
      cin >> data.at(i).at(j); 
    }
  }
  for (int i = 0; i < Q; i++) {
    auto iter = lower_bound(A.begin(),A.end(),data[i][0]);  
    if (iter != data.end() && *iter == data[i][0]) {
      int Z = distance(vec.begin(), iter);
      sum = sum - A[Z];
      A[Z] = data[i][0];
      sum += A[Z];
      cout << sum << endl;
    }     
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:25:14: error: no match for 'operator!=' (operand types are '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' and 'std::vector<std::vector<int> >::iterator')
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |         ~~~~ ^~ ~~~~~~~~~~
      |         |               |
      |         |               __normal_iterator<std::vector<int>*,vector<std::vector<int>>>
      |         __normal_iterator<int*,vector<int>>
In file included from /usr/include/c++/14/regex:68,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:181,
                 from a.cc:1:
/usr/include/c++/14/bits/regex.h:1132:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator!=(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'
 1132 |     operator!=(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1132:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/regex.h:1212:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator!=(__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const sub_match<_BiIter>&)'
 1212 |     operator!=(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1212:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/regex.h:1305:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator!=(const sub_match<_BiIter>&, __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1305 |     operator!=(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1305:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/regex.h:1379:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator!=(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)'
 1379 |     operator!=(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1379:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   'std::vector<std::vector<int> >::iterator' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/regex.h:1473:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator!=(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1473 |     operator!=(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1473:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/regex.h:1547:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator!=(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)'
 1547 |     operator!=(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1547:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   'std::vector<std::vector<int> >::iterator' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/regex.h:1647:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator!=(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1647 |     operator!=(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1647:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/regex.h:2213:5: note: candidate: 'template<class _Bi_iter, class _Alloc> bool std::__cxx11::operator!=(const match_results<_BiIter, _Alloc>&, const match_results<_BiIter, _Alloc>&)'
 2213 |     operator!=(const match_results<_Bi_iter, _Alloc>& __m1,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:2213:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::__cxx11::match_results<_BiIter, _Alloc>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51:
/usr/include/c++/14/bits/stl_pair.h:1052:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator!=(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1052 |     operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1052:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::pair<_T1, _T2>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:67:
/usr/include/c++/14/bits/stl_iterator.h:455:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  455 |     operator!=(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:455:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::reverse_iterator<_Iterator>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/stl_iterator.h:500:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  500 |     operator!=(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:500:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::reverse_iterator<_Iterator>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1686 |     operator!=(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::move_iterator<_IteratorL>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1753 |     operator!=(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::move_iterator<_IteratorL>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
In file included from /usr/include/c++/14/bits/char_traits.h:42,
                 from /usr/include/c++/14/string:42,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/bits/postypes.h:197:5: note: candidate: 'template<class _StateT> bool std::operator!=(const fpos<_StateT>&, const fpos<_StateT>&)'
  197 |     operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:197:5: note:   template argument deduction/substitution failed:
a.cc:25:26: note:   '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' is not derived from 'const std::fpos<_StateT>'
   25 |     if (iter != data.end() && *iter == data[i][0]) {
      |                          ^
In file included from /usr/include/c++/14/string:43:
/usr/include/c++/14/bits/allocator.h:243:5: note: candidate: 'template<class _T1, class _T2> bool std::operator!=(const allocator<_CharT>&, const allocator<_T2>&)'
  243 |     operator!=(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:243:5: note:   template argument deduction/substit