Language: C++

#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define rep(i,n) for(ll i=0;i<(n);i++)
int main(){
  ll n,ans=0;cin>>n;
  vector<ll> a(n),b(n),c(n);
  rep(i,n) cin>>a[i];rep(i,n) cin>>b[i];rep(i,n) cin>>c[i];
  sort(a,a+n);sort(b,b+n);sort(c,c+n);
  rep(i,n){
    ans+=(lower_bound(a,a+n,b[i])-a.begin())*(c.end()-upper_bound(c,c+n,b[i]));
  }
  cout<<ans<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:11: error: no match for 'operator+' (operand types are 'std::vector<long long int>' and 'll' {aka 'long long int'})
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |          ~^~
      |          | |
      |          | ll {aka 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:627:5: note: candidate: 'template<class _Iterator> constexpr std::reverse_iterator<_Iterator> std::operator+(typename reverse_iterator<_Iterator>::difference_type, const reverse_iterator<_Iterator>&)'
  627 |     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:627:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'll' {aka 'long long int'}
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note: candidate: 'template<class _Iterator> constexpr std::move_iterator<_IteratorL> std::operator+(typename move_iterator<_IteratorL>::difference_type, const move_iterator<_IteratorL>&)'
 1798 |     operator+(typename move_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'll' {aka 'long long int'}
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
In file included from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/bits/basic_string.h:3598:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3598 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3598:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   'std::vector<long long int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3616:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3616 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3616:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   mismatched types 'const _CharT*' and 'std::vector<long long int>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3635:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3635 |     operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Alloc>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3635:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'll' {aka 'long long int'}
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3652:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3652 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3652:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   'std::vector<long long int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3670:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, _CharT)'
 3670 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3670:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   'std::vector<long long int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3682:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3682 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3682:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   'std::vector<long long int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3689:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3689 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3689:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   'std::vector<long long int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3696:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3696 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3696:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   'std::vector<long long int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3719:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3719 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3719:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   mismatched types 'const _CharT*' and 'std::vector<long long int>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3726:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3726 |     operator+(_CharT __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3726:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'll' {aka 'long long int'}
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3733:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const _CharT*)'
 3733 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3733:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   'std::vector<long long int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
/usr/include/c++/14/bits/basic_string.h:3740:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, _CharT)'
 3740 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3740:5: note:   template argument deduction/substitution failed:
a.cc:9:12: note:   'std::vector<long long int>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
    9 |   sort(a,a+n);sort(b,b+n);sort(c,c+n);
      |            ^
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:340:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const complex<_Tp>&, const complex<_Tp>&)'
  340 |     operator+(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:340