Language: C++

using namespace std;
#include <bits/stdc++.h>
#define rep(i, s) for (int i = 0; i < s; ++i)
#define repr(i, n) for(int i = n; i >= 0; i--)
#define FOR(i, m, n) for(int i = m; i < n; i++)
#define all(v) (v.begin(), v.end())
#define EACH(i, s) for (__typeof__((s).begin()) i = (s).begin(); i != (s).end(); ++i)
#define VEC(a, n) vector<int>a(n)
#define PQ(a) priority_queue<int>a
#define PQmin(a) priority_queue< int, :vector<int>, greater<int> >a
#define PAIR pair<int, int>
typedef long long ll;
typedef pair<ll, ll> l_l;
typedef pair<int, int> i_i;
#define EPS (1e-7)
#define INF (1e10)
#define PI (acos(-1))
const ll mod = 1000000007;
bool f(string s){
  bool ans=true;
  rep(i,s.size()/2){
    if(s[i]!=s[s.size()/2+i]){
      ans=false;
      break;
    }
  }
  return ans;
}

int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);
  string s;
  int N=s.length()
  string sfw=s.substr(0,(N-1)/2);
  string sbk=s.substr((N+1)/2,(N-1)/2);
  if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
    cout<<"Yes"<<endl;
  else
    cout<<"No"<<endl;

}

Compiler output:
a.cc: In function 'int main()':
a.cc:35:3: error: expected ',' or ';' before 'string'
   35 |   string sfw=s.substr(0,(N-1)/2);
      |   ^~~~~~
a.cc:37:7: error: no match for 'operator==' (operand types are 'std::string' {aka 'std::__cxx11::basic_string<char>'} and 'void')
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |      ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |      |         |
      |      |         void
      |      std::string {aka std::__cxx11::basic_string<char>}
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:2:
/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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'void'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'void'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'void'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::match_results<_BiIter, _Alloc>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::pair<_T1, _T2>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
/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:37:34: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
   37 |   if(s==reverse(s.begin(),s.end())&&sfw==reverse(sfw.begin(),sfw.end())&&sbk==reverse(sbk.begin(),sbk.end()))
      |                                  ^
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>& __