Language: C++

#include <bits/stdc++.h>
using namespace std;
int ans = 0;
void OnestrokePath(int n,vector<vector<int>> &ABC,vector<bool> &ok) {
    bool ok2 = true;
    for(int i = 0; i < ok.size(); i++) {
        if(ok == false && i != n) {
            ok2 = false;
        }
    }
    if(ok2) {
        ans+;
        return;
    }
    ok[n] = true;
    for(int i = 0; i < ABC[n].size(); i++) {
        if(ABC[n][i] == true) {
            continue;
        }
        OnestrokePath(ABC[n][i],ABC,ok);
    }
    return;
}
int main() {
    int N,M;
    cin >> N >> M;
    vector<vector<int>>AB(N);
    vector<bool>flag(N,false);
    for(int i = 0; i < N; i++) {
        int a,b;
        cin >> a >> b;
        a--;
        b--;
        AB[a].push_back(b);
        AB[b].push_back(a);
    }
    OnestrokePath(0,AB,flag);
    cout << ans << endl;
}

Compiler output:
a.cc: In function 'void OnestrokePath(int, std::vector<std::vector<int> >&, std::vector<bool>&)':
a.cc:7:15: error: no match for 'operator==' (operand types are 'std::vector<bool>' and 'bool')
    7 |         if(ok == false && i != n) {
      |            ~~~^~~~~~~~
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:7:18: note:   'std::vector<bool>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   'std::vector<bool>' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   'std::vector<bool>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'bool'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   'std::vector<bool>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'bool'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   'std::vector<bool>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   'std::vector<bool>' is not derived from 'const std::__cxx11::match_results<_BiIter, _Alloc>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
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:7:18: note:   'std::vector<bool>' is not derived from 'const std::pair<_T1, _T2>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
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:7:18: note:   'std::vector<bool>' is not derived from 'const std::reverse_iterator<_Iterator>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   'std::vector<bool>' is not derived from 'const std::reverse_iterator<_Iterator>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   'std::vector<bool>' is not derived from 'const std::move_iterator<_IteratorL>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/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:7:18: note:   'std::vector<bool>' is not derived from 'const std::move_iterator<_IteratorL>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
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:7:18: note:   'std::vector<bool>' is not derived from 'const std::fpos<_StateT>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
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:7:18: note:   'std::vector<bool>' is not derived from 'const std::allocator<_CharT>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
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:7:18: note:   'std::vector<bool>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
    7 |         if(ok == false && i != n) {
      |                  ^~~~~
/usr/include/c++/14/string_view:637:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_