Language: C++

#include <bits/stdc++.h>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <deque>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
#define pi 3.14159265358979323846264338327950L
using namespace std;

int main() {
  int64_t N, j=0, ans=0;
  cin >> N;
  vector<int64_t> A(N);
  vector<int64_t> B(N);
  for (int64_t i=0; i<N; i++) {
    cin >> A[i];
    B[i]=0;
  }
  sort(A.begin(),A.end());
  if (N==1) {
    B[0]=1;
  }
  else {
    B[0]=1;
    for (int64_t i=1; i<N; i++) {
      if (A[i-1]==A[i]) {
        B[j]++;
      }
      else {
        j++;
        B[j]++;
      }
    }
  }
  for (int64_t i=0; i<N; i++) {
    if (B%2==1) {
      ans++;
    }
  }
  cout << ans << endl;

Compiler output:
a.cc: In function 'int main()':
a.cc:46:10: error: no match for 'operator%' (operand types are 'std::vector<long int>' and 'int')
   46 |     if (B%2==1) {
      |         ~^~
      |         | |
      |         | int
      |         std::vector<long int>
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166,
                 from a.cc:1:
/usr/include/c++/14/bits/valarray_after.h:409:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__modulus, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__modulus, typename _Dom1::value_type>::result_type> std::operator%(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  409 |     _DEFINE_EXPR_BINARY_OPERATOR(%, struct std::__modulus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:409:5: note:   template argument deduction/substitution failed:
a.cc:46:11: note:   'std::vector<long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   46 |     if (B%2==1) {
      |           ^
/usr/include/c++/14/bits/valarray_after.h:409:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__modulus, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__modulus, typename _Dom1::value_type>::result_type> std::operator%(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  409 |     _DEFINE_EXPR_BINARY_OPERATOR(%, struct std::__modulus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:409:5: note:   template argument deduction/substitution failed:
a.cc:46:11: note:   'std::vector<long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   46 |     if (B%2==1) {
      |           ^
/usr/include/c++/14/bits/valarray_after.h:409:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__modulus, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__modulus, typename _Dom1::value_type>::result_type> std::operator%(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  409 |     _DEFINE_EXPR_BINARY_OPERATOR(%, struct std::__modulus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:409:5: note:   template argument deduction/substitution failed:
a.cc:46:11: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   46 |     if (B%2==1) {
      |           ^
/usr/include/c++/14/bits/valarray_after.h:409:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__modulus, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__modulus, typename _Dom1::value_type>::result_type> std::operator%(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  409 |     _DEFINE_EXPR_BINARY_OPERATOR(%, struct std::__modulus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:409:5: note:   template argument deduction/substitution failed:
a.cc:46:11: note:   'std::vector<long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   46 |     if (B%2==1) {
      |           ^
/usr/include/c++/14/bits/valarray_after.h:409:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__modulus, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__modulus, typename _Dom1::value_type>::result_type> std::operator%(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  409 |     _DEFINE_EXPR_BINARY_OPERATOR(%, struct std::__modulus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:409:5: note:   template argument deduction/substitution failed:
a.cc:46:11: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   46 |     if (B%2==1) {
      |           ^
/usr/include/c++/14/valarray:1200:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__modulus, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__modulus, _Tp>::result_type> std::operator%(const valarray<_Tp>&, const valarray<_Tp>&)'
 1200 | _DEFINE_BINARY_OPERATOR(%, __modulus)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1200:1: note:   template argument deduction/substitution failed:
a.cc:46:11: note:   'std::vector<long int>' is not derived from 'const std::valarray<_Tp>'
   46 |     if (B%2==1) {
      |           ^
/usr/include/c++/14/valarray:1200:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__modulus, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__modulus, _Tp>::result_type> std::operator%(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1200 | _DEFINE_BINARY_OPERATOR(%, __modulus)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1200:1: note:   template argument deduction/substitution failed:
a.cc:46:11: note:   'std::vector<long int>' is not derived from 'const std::valarray<_Tp>'
   46 |     if (B%2==1) {
      |           ^
/usr/include/c++/14/valarray:1200:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__modulus, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__modulus, _Tp>::result_type> std::operator%(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1200 | _DEFINE_BINARY_OPERATOR(%, __modulus)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1200:1: note:   template argument deduction/substitution failed:
a.cc:46:11: note:   mismatched types 'const std::valarray<_Tp>' and 'int'
   46 |     if (B%2==1) {
      |           ^
a.cc:50:23: error: expected '}' at end of input
   50 |   cout << ans << endl;
      |                       ^
a.cc:20:12: note: to match this '{'
   20 | int main() {
      |            ^