Language: C++

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
typedef pair<int, int> P;
ll Mod = 1000000007;
int main() {
  string S;
  cin >> S;
  bool N = false;
  bool W = false;
  bool S = false;
  bool E = false;
  for (int i = 0; i < S.size(); i++) {
    if (S[i] == 'N') {
      N = true;
    }
    if (S[i] == 'W') {
      W = true;
    } 
    if (S[i] == 'S') {
      S = true;
    } 
    if (S[i] == 'E') {
      E = true;
    } 
  }
  bool ans = true;
  if ((!N && S) || (N && !S)) {
    ans = false;
  }
  if ((!W && E) || (W && !E)) {
    ans = false;
  }
  if (ans) cout << "Yes" << endl;
  else cout << "No" << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:11:8: error: conflicting declaration 'bool S'
   11 |   bool S = false;
      |        ^
a.cc:7:10: note: previous declaration as 'std::string S'
    7 |   string S;
      |          ^
a.cc:28:11: error: no match for 'operator&&' (operand types are 'bool' and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
   28 |   if ((!N && S) || (N && !S)) {
      |        ~~ ^~ ~
      |        |     |
      |        bool  std::string {aka std::__cxx11::basic_string<char>}
a.cc:28:11: note: candidate: 'operator&&(bool, bool)' (built-in)
   28 |   if ((!N && S) || (N && !S)) {
      |        ~~~^~~~
a.cc:28:11: note:   no known conversion for argument 2 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'bool'
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:415:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__logical_and, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__logical_and, typename _Dom1::value_type>::result_type> std::operator&&(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  415 |     _DEFINE_EXPR_BINARY_OPERATOR(&&, struct std::__logical_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:415:5: note:   template argument deduction/substitution failed:
a.cc:28:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'bool'
   28 |   if ((!N && S) || (N && !S)) {
      |              ^
/usr/include/c++/14/bits/valarray_after.h:415:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_and, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__logical_and, typename _Dom1::value_type>::result_type> std::operator&&(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  415 |     _DEFINE_EXPR_BINARY_OPERATOR(&&, struct std::__logical_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:415:5: note:   template argument deduction/substitution failed:
a.cc:28:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'bool'
   28 |   if ((!N && S) || (N && !S)) {
      |              ^
/usr/include/c++/14/bits/valarray_after.h:415:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_and, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__logical_and, typename _Dom1::value_type>::result_type> std::operator&&(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  415 |     _DEFINE_EXPR_BINARY_OPERATOR(&&, struct std::__logical_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:415:5: note:   template argument deduction/substitution failed:
a.cc:28:14: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   28 |   if ((!N && S) || (N && !S)) {
      |              ^
/usr/include/c++/14/bits/valarray_after.h:415:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_and, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__logical_and, typename _Dom1::value_type>::result_type> std::operator&&(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  415 |     _DEFINE_EXPR_BINARY_OPERATOR(&&, struct std::__logical_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:415:5: note:   template argument deduction/substitution failed:
a.cc:28:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'bool'
   28 |   if ((!N && S) || (N && !S)) {
      |              ^
/usr/include/c++/14/bits/valarray_after.h:415:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_and, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__logical_and, typename _Dom1::value_type>::result_type> std::operator&&(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  415 |     _DEFINE_EXPR_BINARY_OPERATOR(&&, struct std::__logical_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:415:5: note:   template argument deduction/substitution failed:
a.cc:28:14: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   28 |   if ((!N && S) || (N && !S)) {
      |              ^
/usr/include/c++/14/valarray:1206:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__logical_and, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__logical_and, _Tp>::result_type> std::operator&&(const valarray<_Tp>&, const valarray<_Tp>&)'
 1206 | _DEFINE_BINARY_OPERATOR(&&, __logical_and)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1206:1: note:   template argument deduction/substitution failed:
a.cc:28:14: note:   mismatched types 'const std::valarray<_Tp>' and 'bool'
   28 |   if ((!N && S) || (N && !S)) {
      |              ^
/usr/include/c++/14/valarray:1206:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__logical_and, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__logical_and, _Tp>::result_type> std::operator&&(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1206 | _DEFINE_BINARY_OPERATOR(&&, __logical_and)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1206:1: note:   template argument deduction/substitution failed:
a.cc:28:14: note:   mismatched types 'const std::valarray<_Tp>' and 'bool'
   28 |   if ((!N && S) || (N && !S)) {
      |              ^
/usr/include/c++/14/valarray:1206:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__logical_and, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__logical_and, _Tp>::result_type> std::operator&&(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1206 | _DEFINE_BINARY_OPERATOR(&&, __logical_and)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1206:1: note:   template argument deduction/substitution failed:
a.cc:28:14: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::valarray<_Tp>'
   28 |   if ((!N && S) || (N && !S)) {
      |              ^
a.cc:28:26: error: no match for 'operator!' (operand type is 'std::string' {aka 'std::__cxx11::basic_string<char>'})
   28 |   if ((!N && S) || (N && !S)) {
      |                          ^~
a.cc:28:26: note: candidate: 'operator!(bool)' (built-in)
a.cc:28:26: note:   no known conversion for argument 1 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'bool'