Language: C++

#include <bits/stdc++.h>
#define rep(i,n) for(int i=0; i<(n); ++i)
using namespace std;
int main() {
  int N, K;
  cin >> N >> K;
  vector<int> A[N];
  rep(i,N)
    A[i] = i + 1;
  rep(i,N) {
    int d;
    cin >> d;
    rep(j,d) {
      int A;
      cin >> A;
      rep(k,n) {
        if (A == A[k])
          A[k] = 0;
      }
    }
  }
  rep(i,N) {
    if(A[i] == 0)
      N = N - 1;
  }
  cout << N << endl;
  
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:16: error: no match for 'operator=' (operand types are 'std::vector<int>' and 'int')
    9 |     A[i] = i + 1;
      |                ^
In file included from /usr/include/c++/14/vector:72,
                 from /usr/include/c++/14/functional:64,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/vector.tcc:210:5: note: candidate: 'std::vector<_Tp, _Alloc>& std::vector<_Tp, _Alloc>::operator=(const std::vector<_Tp, _Alloc>&) [with _Tp = int; _Alloc = std::allocator<int>]'
  210 |     vector<_Tp, _Alloc>::
      |     ^~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/vector.tcc:211:42: note:   no known conversion for argument 1 from 'int' to 'const std::vector<int>&'
  211 |     operator=(const vector<_Tp, _Alloc>& __x)
      |               ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
In file included from /usr/include/c++/14/vector:66:
/usr/include/c++/14/bits/stl_vector.h:766:7: note: candidate: 'std::vector<_Tp, _Alloc>& std::vector<_Tp, _Alloc>::operator=(std::vector<_Tp, _Alloc>&&) [with _Tp = int; _Alloc = std::allocator<int>]'
  766 |       operator=(vector&& __x) noexcept(_Alloc_traits::_S_nothrow_move())
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:766:26: note:   no known conversion for argument 1 from 'int' to 'std::vector<int>&&'
  766 |       operator=(vector&& __x) noexcept(_Alloc_traits::_S_nothrow_move())
      |                 ~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:788:7: note: candidate: 'std::vector<_Tp, _Alloc>& std::vector<_Tp, _Alloc>::operator=(std::initializer_list<_Tp>) [with _Tp = int; _Alloc = std::allocator<int>]'
  788 |       operator=(initializer_list<value_type> __l)
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:788:46: note:   no known conversion for argument 1 from 'int' to 'std::initializer_list<int>'
  788 |       operator=(initializer_list<value_type> __l)
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
a.cc:16:13: error: 'n' was not declared in this scope
   16 |       rep(k,n) {
      |             ^
a.cc:2:34: note: in definition of macro 'rep'
    2 | #define rep(i,n) for(int i=0; i<(n); ++i)
      |                                  ^
a.cc:17:19: error: invalid types 'int[int]' for array subscript
   17 |         if (A == A[k])
      |                   ^
a.cc:18:12: error: invalid types 'int[int]' for array subscript
   18 |           A[k] = 0;
      |            ^
a.cc:23:13: error: no match for 'operator==' (operand types are 'std::vector<int>' and 'int')
   23 |     if(A[i] == 0)
      |        ~~~~ ^~ ~
      |           |    |
      |           |    int
      |           std::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:
/usr/include/c++/14/bits/regex.h:1103:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator==(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'
 1103 |     operator==(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1103:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/regex.h:1199:5: 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>&)'
 1199 |     operator==(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1199:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/regex.h:1274:5: 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>&)'
 1274 |     operator==(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1274:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/regex.h:1366:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)'
 1366 |     operator==(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1366:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/regex.h:1441:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1441 |     operator==(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1441:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/regex.h:1534:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)'
 1534 |     operator==(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1534:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/regex.h:1613:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1613 |     operator==(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1613:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/regex.h:2186:5: note: candidate: 'template<class _Bi_iter, class _Alloc> bool std::__cxx11::operator==(const match_results<_BiIter, _Alloc>&, const match_results<_BiIter, _Alloc>&)'
 2186 |     operator==(const match_results<_Bi_iter, _Alloc>& __m1,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:2186:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::__cxx11::match_results<_BiIter, _Alloc>'
   23 |     if(A[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:1033:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator==(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1033 |     operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1033:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::pair<_T1, _T2>'
   23 |     if(A[i] == 0)
      |                ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:67:
/usr/include/c++/14/bits/stl_iterator.h:441:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  441 |     operator==(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:441:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::reverse_iterator<_Iterator>'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/stl_iterator.h:486:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  486 |     operator==(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:486:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::reverse_iterator<_Iterator>'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1667 |     operator==(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::move_iterator<_IteratorL>'
   23 |     if(A[i] == 0)
      |                ^
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1737 |     operator==(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note:   template argument deduction/substitution failed:
a.cc:23:16: note:   'std::vector<int>' is not derived from 'const std::move_iterator<_IteratorL>'
   23 |     if(A[i] == 0)
      |                ^
In file included from /usr/include/c++/14/bits/ch