Language: C++

#include <bits/stdc++.h>
using namespace std;
using ll = __int128;
using ld = long double;
const ld eps = 1e-6;

ll combi(ll n, ll k) {
	assert(k >= 0 && k <= n);
	ll res = 1;
	for (int i = 1; i <= k; i++) {
		res = res * (n - k + i) / i;
	}
	return res;
}

int main()
{
	int N, A, B;
	cin >> N >> A >> B;
	vector<ll> v(N);
	for (int i = 0; i < N; i++) {
		cin >> v[i];
	}
	sort(v.begin(), v.end());
	ll sum = 0, cnt = 0, res = 0;
	ld mav = 0;
	for (int i = 0; i < A - 1; i++) {
		sum += v[N - i - 1];
		cnt++;
	}
	for (int i = A - 1; i < B; i++) {
		sum += v[N - i - 1];
		cnt++;
		ld av = (ld)sum / cnt;
		if (mav <= av + eps) {
			res = 0;
			mav = av;
		}
		if (av >= mav - eps) {
			res += combi(count(v.begin(), v.end(), v[N - i - 1]), (upper_bound(v.begin(), v.end(), v[N - i - 1]) - v.begin()) - (N - i - 1));
		}
	}
	cout << fixed << setprecision(7) << mav << endl;
	cout << res << endl;
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:22:21: error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'})
   22 |                 cin >> v[i];
In file included from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127,
                 from a.cc:1:
/usr/include/c++/14/istream:170:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  170 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:170:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:170:7: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:174:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  174 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:174:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:174:7: error: cannot bind non-const lvalue reference of type 'short int&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:177:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  177 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:177:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:177:7: error: cannot bind non-const lvalue reference of type 'short unsigned int&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:181:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  181 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:181:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:181:7: error: cannot bind non-const lvalue reference of type 'int&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:184:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  184 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:184:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:184:7: error: cannot bind non-const lvalue reference of type 'unsigned int&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:188:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  188 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:188:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:188:7: error: cannot bind non-const lvalue reference of type 'long int&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:192:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  192 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:192:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:192:7: error: cannot bind non-const lvalue reference of type 'long unsigned int&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  199 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:199:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:199:7: error: cannot bind non-const lvalue reference of type 'long long int&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:203:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  203 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:203:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:203:7: error: cannot bind non-const lvalue reference of type 'long long unsigned int&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:219:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  219 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:219:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:219:7: error: cannot bind non-const lvalue reference of type 'float&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:223:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  223 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:223:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:223:7: error: cannot bind non-const lvalue reference of type 'double&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:227:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  227 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:227:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:227:7: error: cannot bind non-const lvalue reference of type 'long double&' to a value of type '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'}
/usr/include/c++/14/istream:328:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
/usr/include/c++/14/istream:328:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:328:7: error: invalid conversion from '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'} to 'void*' [-fpermissive]
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
      |       |
      |       __gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type {aka __int128}
/usr/include/c++/14/istream:328:7: error: cannot bind rvalue '(void*)((long int)v.std::vector<__int128>::operator[](((std::vector<__int128>::size_type)i)))' to 'void*&'
/usr/include/c++/14/istream:122:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:7: note:   conversion of argument 1 would be ill-formed:
/usr/include/c++/14/istream:122:7: error: invalid conversion from '__gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type' {aka '__int128'} to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'} [-fpermissive]
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
      |       |
      |       __gnu_cxx::__alloc_traits<std::allocator<__int128>, __int128>::value_type {aka __int128}
/usr/include/c++/14/istream:126:7: note: candidate