Language: C++

#include<algorithm>
#include<bitset>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<map>
#include<iostream>
#include<queue>
#include<set>
#include<stack>
#include<string>
#include<vector>
using namespace std;
#define ll long long
#define f(i,a,b) for(int i=a;i<=b;i++)
inline ll read(){
   int s=0,w=1;
   char ch=getchar();
   while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
   while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
   return s*w;
}
#define d read()
string s[2]={"ABC","ARC"};
int main(){
	string ss;
	cin>>ss;
	if(s==s[0])cout<<s[1];
	else cout<<s[0];
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:28:13: error: no match for 'operator==' (operand types are 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'} and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
   28 |         if(s==s[0])cout<<s[1];
      |            ~^~~~~~
      |            |     |
      |            |     std::string {aka std::__cxx11::basic_string<char>}
      |            std::string [2] {aka std::__cxx11::basic_string<char> [2]}
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from a.cc:1:
/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:28:18: note:   mismatched types 'const std::pair<_T1, _T2>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
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:28:18: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
/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:28:18: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
/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:28:18: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
/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:28:18: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
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 a.cc:2:
/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:28:18: note:   mismatched types 'const std::fpos<_StateT>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
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:28:18: note:   mismatched types 'const std::allocator<_CharT>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
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:28:18: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'std::string*' {aka 'std::__cxx11::basic_string<char>*'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
/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, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:637:5: note:   template argument deduction/substitution failed:
a.cc:28:18: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'std::string*' {aka 'std::__cxx11::basic_string<char>*'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
/usr/include/c++/14/string_view:644:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  644 |     operator==(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:644:5: note:   template argument deduction/substitution failed:
a.cc:28:18: note:   'std::__cxx11::basic_string<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
/usr/include/c++/14/bits/basic_string.h:3755:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3755 |     operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3755:5: note:   template argument deduction/substitution failed:
a.cc:28:18: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
/usr/include/c++/14/bits/basic_string.h:3772:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3772 |     operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3772:5: note:   template argument deduction/substitution failed:
a.cc:28:18: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
/usr/include/c++/14/bits/basic_string.h:3819:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3819 |     operator==(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3819:5: note:   template argument deduction/substitution failed:
a.cc:28:18: note:   deduced conflicting types for parameter '_CharT' ('std::__cxx11::basic_string<char>' and 'char')
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
In file included from /usr/include/c++/14/bits/memory_resource.h:47,
                 from /usr/include/c++/14/string:68:
/usr/include/c++/14/tuple:2558:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const tuple<_UTypes ...>&, const tuple<_Elements ...>&)'
 2558 |     operator==(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/usr/include/c++/14/tuple:2558:5: note:   template argument deduction/substitution failed:
a.cc:28:18: note:   mismatched types 'const std::tuple<_UTypes ...>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^
In file included from /usr/include/c++/14/map:63,
                 from a.cc:6:
/usr/include/c++/14/bits/stl_map.h:1512:5: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator==(const map<_Key, _Tp, _Compare, _Allocator>&, const map<_Key, _Tp, _Compare, _Allocator>&)'
 1512 |     operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_map.h:1512:5: note:   template argument deduction/substitution failed:
a.cc:28:18: note:   mismatched types 'const std::map<_Key, _Tp, _Compare, _Allocator>' and 'std::string [2]' {aka 'std::__cxx11::basic_string<char> [2]'}
   28 |         if(s==s[0])cout<<s[1];
      |                  ^