Language: C++

#include <iostream>
#include <cstdlib>
#include <list>
using namespace std;

int main() {
    list<int>L; int n, x; char s[15];
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> s;
        if (s[0] == 'i')cin >> x,  L.push_front(x);
        else if (s[6] == 'F')L.pop_front();
        else if (s[6] == 'L')L.pop_back();
        else {
            cin >> x;
            for (list<int>::iterator it = L.begin(); it<L.end(); it++)
                if (*it == x) {
                    L.erase(it); break;
                }
        }

    }
    n = 0;
    for (list<int>::iterator it = L.begin(); it<L.end(); it++) {
        if (n++)cout << " ";
        cout << *it;
    }
    cout << endl;
    return 0;
}




Compiler output:
a.cc: In function 'int main()':
a.cc:16:56: error: no match for 'operator<' (operand types are 'std::__cxx11::list<int>::iterator' and 'std::__cxx11::list<int>::iterator')
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                      ~~^~~~~~~~
      |                                                      |       |
      |                                                      |       _List_iterator<[...]>
      |                                                      _List_iterator<[...]>
In file included from /usr/include/c++/14/string:48,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_iterator.h:448:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  448 |     operator<(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:448:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::__cxx11::list<int>::iterator' is not derived from 'const std::reverse_iterator<_Iterator>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
/usr/include/c++/14/bits/stl_iterator.h:493:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  493 |     operator<(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:493:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::__cxx11::list<int>::iterator' is not derived from 'const std::reverse_iterator<_Iterator>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
/usr/include/c++/14/bits/stl_iterator.h:1694:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1694 |     operator<(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1694:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::__cxx11::list<int>::iterator' is not derived from 'const std::move_iterator<_IteratorL>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
/usr/include/c++/14/bits/stl_iterator.h:1760:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1760 |     operator<(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1760:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::__cxx11::list<int>::iterator' is not derived from 'const std::move_iterator<_IteratorL>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/string:51:
/usr/include/c++/14/bits/stl_pair.h:1045:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator<(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1045 |     operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1045:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::__cxx11::list<int>::iterator' is not derived from 'const std::pair<_T1, _T2>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
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:673:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  673 |     operator< (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:673:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::_List_iterator<int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
/usr/include/c++/14/string_view:680:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  680 |     operator< (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:680:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::_List_iterator<int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
/usr/include/c++/14/string_view:688:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  688 |     operator< (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:688:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::_List_iterator<int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
/usr/include/c++/14/bits/basic_string.h:3874:5: 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>&)'
 3874 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3874:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::__cxx11::list<int>::iterator' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
/usr/include/c++/14/bits/basic_string.h:3888:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3888 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3888:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::__cxx11::list<int>::iterator' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
/usr/include/c++/14/bits/basic_string.h:3901:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3901 |     operator<(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3901:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   mismatched types 'const _CharT*' and 'std::_List_iterator<int>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
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:2600:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator<(const tuple<_UTypes ...>&, const tuple<_Elements ...>&)'
 2600 |     operator<(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/usr/include/c++/14/tuple:2600:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::__cxx11::list<int>::iterator' is not derived from 'const std::tuple<_UTypes ...>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
In file included from /usr/include/c++/14/list:65,
                 from a.cc:3:
/usr/include/c++/14/bits/stl_list.h:2188:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const __cxx11::list<_Tp, _Alloc>&, const __cxx11::list<_Tp, _Alloc>&)'
 2188 |     operator<(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_list.h:2188:5: note:   template argument deduction/substitution failed:
a.cc:16:63: note:   'std::__cxx11::list<int>::iterator' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
   16 |             for (list<int>::iterator it = L.begin(); it<L.end(); it++)
      |                                                               ^
In file included from /usr/include/c++/14/bits/ios_base.h:46:
/usr/include/c++/14/system_error:324:3: note: candidate: 'bool std::operator<(const error_code&, const error_code&)'
  324 |   operator<(const error_code& __lhs, const error_code& __rhs) noexcept
      |   ^~~~~~~~
/usr/include/c++/14