Language: C++

#include<bits/stdc++.h>

using namespace std;

void dfs(vector<vector<int>> &dp,vector<vector<int>> &adj,int i,int parent){
  dp[i][0] = 1;
  dp[i][1]=1;
  for(auto e: adj){
    if(e == parent) continue;
    dfs(dp,adj,e,i);
    dp[i][1] = dp[i][1] * (dp[e][0]);
    dp[i][0] = dp[i][0]*(dp[e][0]*dp[e][1]);
  }
  return;
}

int main(){
  int n;
  cin >> n;
  vector<vector<int>> adj(n+1);
  for(int i=0;i<n;i++){
    cin >> a >> b;
    adj[a].push_back(b);
    adj[b].push_back(a);
  }
  
  vector<vector<int>> dp(n+1,vector<int>(2,0));
  vector<int> parent(n+1,-1);
  dfs(dp,1,parent);
  cout << dp[1][0] + dp[1][1] << endl;
  return 0;
}


Compiler output:
a.cc: In function 'void dfs(std::vector<std::vector<int> >&, std::vector<std::vector<int> >&, int, int)':
a.cc:9:10: error: no match for 'operator==' (operand types are 'std::vector<int>' and 'int')
    9 |     if(e == parent) continue;
      |        ~ ^~ ~~~~~~
      |        |    |
      |        |    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,
                 from a.cc:1:
/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:9:13: note:   'std::vector<int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   'std::vector<int>' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   'std::vector<int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   'std::vector<int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   'std::vector<int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   'std::vector<int>' is not derived from 'const std::__cxx11::match_results<_BiIter, _Alloc>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
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:9:13: note:   'std::vector<int>' is not derived from 'const std::pair<_T1, _T2>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
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:9:13: note:   'std::vector<int>' is not derived from 'const std::reverse_iterator<_Iterator>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   'std::vector<int>' is not derived from 'const std::reverse_iterator<_Iterator>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   'std::vector<int>' is not derived from 'const std::move_iterator<_IteratorL>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/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:9:13: note:   'std::vector<int>' is not derived from 'const std::move_iterator<_IteratorL>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
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:192:5: note: candidate: 'template<class _StateT> bool std::operator==(const fpos<_StateT>&, const fpos<_StateT>&)'
  192 |     operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:192:5: note:   template argument deduction/substitution failed:
a.cc:9:13: note:   'std::vector<int>' is not derived from 'const std::fpos<_StateT>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
In file included from /usr/include/c++/14/string:43:
/usr/include/c++/14/bits/allocator.h:235:5: note: candidate: 'template<class _T1, class _T2> bool std::operator==(const allocator<_CharT>&, const allocator<_T2>&)'
  235 |     operator==(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:235:5: note:   template argument deduction/substitution failed:
a.cc:9:13: note:   'std::vector<int>' is not derived from 'const std::allocator<_CharT>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:629:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  629 |     operator==(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:629:5: note:   template argument deduction/substitution failed:
a.cc:9:13: note:   'std::vector<int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
    9 |     if(e == parent) continue;
      |             ^~~~~~
/usr/include/c++/14/string_view:637:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  637 |     operator==(basic_string_view<_CharT,