Language: C++

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

typedef long long ll;

const ll MAX_N = 2e5+10;

int main(int argc, char const *argv[])
{
    ll n;
    int a[MAX_N] = {0}, x[MAX_N] = {0};
    cin >> n;
    for (ll i = 1; i <= n; ++i) {
        cin >> a[i] << endl;
    }

    vector<ll> vec;
    bool tf = true;

    for (ll i = n; i > 0 && tf; --i) {
        if (2*i>n) {
            x[i] = a[i];
        }
        else {
            x[i] = (x[i*2]+a[i]) % 2;
        }
    }

    for (ll i = 1; i <= n; ++i) {
        if (x[i] == 1) {
            vec.emplace_back(i);
        }
    }

    if (tf) {
        cout << vec.size() << endl;
        for (int i = 0; i < vec.size(); ++i) {
            printf("%lld\n", vec[i]);
        }
    }
    else cout << -1 << endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:17:21: error: no match for 'operator<<' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and '<unresolved overloaded function type>')
   17 |         cin >> a[i] << endl;
      |         ~~~~~~~~~~~~^~~~~~~
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54,
                 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/string_view:763:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, basic_string_view<_CharT, _Traits>)'
  763 |     operator<<(basic_ostream<_CharT, _Traits>& __os,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:763:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/bits/basic_string.h:4077:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 4077 |     operator<<(basic_ostream<_CharT, _Traits>& __os,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:4077:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
In file included from /usr/include/c++/14/bits/memory_resource.h:38,
                 from /usr/include/c++/14/string:68:
/usr/include/c++/14/cstddef:125:5: note: candidate: 'template<class _IntegerType> constexpr std::__byte_op_t<_IntegerType> std::operator<<(byte, _IntegerType)'
  125 |     operator<<(byte __b, _IntegerType __shift) noexcept
      |     ^~~~~~~~
/usr/include/c++/14/cstddef:125:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   couldn't deduce template parameter '_IntegerType'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
In file included from /usr/include/c++/14/bits/ios_base.h:46:
/usr/include/c++/14/system_error:339:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, const error_code&)'
  339 |     operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
      |     ^~~~~~~~
/usr/include/c++/14/system_error:339:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:563:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, _CharT)'
  563 |     operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:563:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:573:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, char)'
  573 |     operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:573:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:579:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, char)'
  579 |     operator<<(basic_ostream<char, _Traits>& __out, char __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:579:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:590:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, signed char)'
  590 |     operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:590:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:595:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, unsigned char)'
  595 |     operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:595:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:654:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, const _CharT*)'
  654 |     operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:654:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
In file included from /usr/include/c++/14/ostream:1022:
/usr/include/c++/14/bits/ostream.tcc:307:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, const char*)'
  307 |     operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/bits/ostream.tcc:307:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:671:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, const char*)'
  671 |     operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:671:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:684:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, const signed char*)'
  684 |     operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:684:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:689:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, const unsigned char*)'
  689 |     operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:689:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   17 |         cin >> a[i] << endl;
      |                        ^~~~
/usr/include/c++/14/ostream:810:5: note: candidate: 'template<class _Ostream, class _Tp> _Ostream&& std::operator<<(_Ostream&&, const _Tp&)'
  810 |     operator<<(_Ostream&& __os, const _Tp& __x)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:810:5: note:   template argument deduction/substitution failed:
a.cc:17:24: note:   couldn't deduce template parameter '_Tp'
   17 |         cin >> a[i] << endl;
      |                        ^~~~