Language: C++

#include <bits/stdc++.h>
#define inf 100000000
using namespace std;
#define rep(i,n) for(int i = 0; i < n; ++i)
typedef long long ll;
int main (){
    ll n;
    cin >> n;

    vector<ll> a(n),b(n),c(n),r(n),l(n);

    rep(i,n){
        cin >> a[i];
    }

    rep(i,n){
        cin >> b[i];
    }
    
    rep(i,n){
        cin >> c[i];
    }

    sort(a.begin(),a.end());
    sort(b.begin(),b.end());
    sort(c.begin(),c.end());

    rep(i,n){
        ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
        ll ic = c.end()-upper_bound(c.begin(),c.end(),b[i]);
        l[i]=ia;
        r[i]=ic;
    }
    ll sum=0;
    rep(i,n){
        sum+=l[i]*r[i];
    }
    cout << sum <<endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:29:52: error: no match for 'operator-' (operand types are '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' and '<unresolved overloaded function type>')
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
      |                            |                          |
      |                            |                          <unresolved overloaded function type>
      |                            __gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >
In file included from /usr/include/c++/14/bits/stl_algobase.h:67,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_iterator.h:1148:7: note: candidate: '__gnu_cxx::__normal_iterator<_Iterator, _Container> __gnu_cxx::__normal_iterator<_Iterator, _Container>::operator-(difference_type) const [with _Iterator = long long int*; _Container = std::vector<long long int>; difference_type = long int]'
 1148 |       operator-(difference_type __n) const _GLIBCXX_NOEXCEPT
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1148:33: note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type' {aka 'long int'}
 1148 |       operator-(difference_type __n) const _GLIBCXX_NOEXCEPT
      |                 ~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_iterator.h:618:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr decltype ((__y.base() - __x.base())) std::operator-(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  618 |     operator-(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:618:5: note:   template argument deduction/substitution failed:
a.cc:29:55: note:   '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' is not derived from 'const std::reverse_iterator<_Iterator>'
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                                                       ^~~~~
/usr/include/c++/14/bits/stl_iterator.h:1790:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr decltype ((__x.base() - __y.base())) std::operator-(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1790 |     operator-(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1790:5: note:   template argument deduction/substitution failed:
a.cc:29:55: note:   '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' is not derived from 'const std::move_iterator<_IteratorL>'
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                                                       ^~~~~
In file included from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/complex:370:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const complex<_Tp>&, const complex<_Tp>&)'
  370 |     operator-(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:370:5: note:   template argument deduction/substitution failed:
a.cc:29:55: note:   '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' is not derived from 'const std::complex<_Tp>'
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                                                       ^~~~~
/usr/include/c++/14/complex:379:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const complex<_Tp>&, const _Tp&)'
  379 |     operator-(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:379:5: note:   template argument deduction/substitution failed:
a.cc:29:55: note:   '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' is not derived from 'const std::complex<_Tp>'
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                                                       ^~~~~
/usr/include/c++/14/complex:388:5: note: candidate: 'std::complex<_Tp> std::operator-(const _Tp&, const complex<_Tp>&) [with _Tp = __gnu_cxx::__normal_iterator<long long int*, vector<long long int> >]'
  388 |     operator-(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:388:51: note:   no known conversion for argument 2 from '<unresolved overloaded function type>' to 'const std::complex<__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> > >&'
  388 |     operator-(const _Tp& __x, const complex<_Tp>& __y)
      |                               ~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/complex:465:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const complex<_Tp>&)'
  465 |     operator-(const complex<_Tp>& __x)
      |     ^~~~~~~~
/usr/include/c++/14/complex:465:5: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166:
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:29:55: note:   '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                                                       ^~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:29:55: note:   '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                                                       ^~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:29:55: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'std::vector<long long int>::const_iterator (std::vector<long long int>::*)() const noexcept'
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                                                       ^~~~~
a.cc:29:55: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'std::vector<long long int>::iterator (std::vector<long long int>::*)() noexcept'
a.cc:29:55: note:   couldn't deduce template parameter '_Dom'
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:29:55: note:   '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                                                       ^~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:29:55: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'std::vector<long long int>::const_iterator (std::vector<long long int>::*)() const noexcept'
   29 |         ll ia = lower_bound(a.begin(),a.end(),b[i])-a.begin;
      |                                                       ^~~~~
a.cc:29:55: note