foo.cc: In function 'int main(int, char**)':
foo.cc:20:17: error: reference to 'end' is ambiguous
   20 |     scanf("%c",&end);
      |                 ^~~
In file included from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:95,
                 from foo.cc:1:
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/valarray:1253:5: note: candidates are: 'template<class _Tp> const _Tp* std::end(const std::valarray<_Tp>&)'
 1253 |     end(const valarray<_Tp>& __va) noexcept
      |     ^~~
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/valarray:1237:5: note:                 'template<class _Tp> _Tp* std::end(std::valarray<_Tp>&)'
 1237 |     end(valarray<_Tp>& __va) noexcept
      |     ^~~
In file included from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/string:54,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/locale_classes.h:40,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/ios_base.h:41,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/ios:42,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/istream:38,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/sstream:38,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/complex:45,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/ccomplex:39,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:54,
                 from foo.cc:1:
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/range_access.h:100:5: note:                 'template<class _Tp, long unsigned int _Nm> _Tp* std::end(_Tp (&)[_Nm])'
  100 |     end(_Tp (&__arr)[_Nm]) noexcept
      |     ^~~
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/range_access.h:81:5: note:                 'template<class _Container> decltype (__cont.end()) std::end(const _Container&)'
   81 |     end(const _Container& __cont) -> decltype(__cont.end())
      |     ^~~
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/range_access.h:71:5: note:                 'template<class _Container> decltype (__cont.end()) std::end(_Container&)'
   71 |     end(_Container& __cont) -> decltype(__cont.end())
      |     ^~~
In file included from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/range_access.h:36,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/string:54,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/locale_classes.h:40,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/ios_base.h:41,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/ios:42,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/istream:38,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/sstream:38,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/complex:45,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/ccomplex:39,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:54,
                 from foo.cc:1:
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/initializer_list:101:5: note:                 'template<class _Tp> constexpr const _Tp* std::end(std::initializer_list<_Tp>)'
  101 |     end(initializer_list<_Tp> __ils) noexcept
      |     ^~~
foo.cc:3:19: note:                 'char end'
    3 | char c,s[13],*p=s,end;
      |                   ^~~
foo.cc:21:16: error: expected primary-expression before 'int'
   21 |     if(sum%11==int(end-'0'))
      |                ^~~
foo.cc:21:16: error: expected ')' before 'int'
   21 |     if(sum%11==int(end-'0'))
      |       ~        ^~~
      |                )
foo.cc:27:32: error: reference to 'end' is ambiguous
   27 |                 if(sum%11==10&&end=='X')
      |                                ^~~
In file included from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:95,
                 from foo.cc:1:
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/valarray:1253:5: note: candidates are: 'template<class _Tp> const _Tp* std::end(const std::valarray<_Tp>&)'
 1253 |     end(const valarray<_Tp>& __va) noexcept
      |     ^~~
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/valarray:1237:5: note:                 'template<class _Tp> _Tp* std::end(std::valarray<_Tp>&)'
 1237 |     end(valarray<_Tp>& __va) noexcept
      |     ^~~
In file included from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/string:54,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/locale_classes.h:40,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/ios_base.h:41,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/ios:42,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/istream:38,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/sstream:38,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/complex:45,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/ccomplex:39,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:54,
                 from foo.cc:1:
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/range_access.h:100:5: note:                 'template<class _Tp, long unsigned int _Nm> _Tp* std::end(_Tp (&)[_Nm])'
  100 |     end(_Tp (&__arr)[_Nm]) noexcept
      |     ^~~
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/range_access.h:81:5: note:                 'template<class _Container> decltype (__cont.end()) std::end(const _Container&)'
   81 |     end(const _Container& __cont) -> decltype(__cont.end())
      |     ^~~
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/range_access.h:71:5: note:                 'template<class _Container> decltype (__cont.end()) std::end(_Container&)'
   71 |     end(_Container& __cont) -> decltype(__cont.end())
      |     ^~~
In file included from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/range_access.h:36,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/string:54,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/locale_classes.h:40,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/bits/ios_base.h:41,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/ios:42,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/istream:38,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/sstream:38,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/complex:45,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/ccomplex:39,
                 from /nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:54,
                 from foo.cc:1:
/nix/store/wy4ywjsch9q2hj5lphqjdg9p2kf7w0ls-gcc-11.3.0/include/c++/11.3.0/initializer_list:101:5: note:                 'template<class _Tp> constexpr const _Tp* std::end(std::initializer_list<_Tp>)'
  101 |     end(initializer_list<_Tp> __ils) noexcept
      |     ^~~
foo.cc:3:19: note:                 'char end'
    3 | char c,s[13],*p=s,end;
      |                   ^~~

[Hydro](https://hydro.ac)提供评测服务