Language: C++

#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <string>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <iomanip>
#include <utility>
#include <tuple>
#include <functional>
#include <bitset>
#include <cassert>
#include <complex>
#include <time.h>
#define ll long long
#define double long double
#define itn int
#define endl '\n'
#define co(ans) cout<<ans<<endl;
#define COYE cout<<"YES"<<endl;
#define COYe cout<<"Yes"<<endl;
#define COye cout<<"yes"<<endl;
#define CONO cout<<"NO"<<endl;
#define CONo cout<<"No"<<endl;
#define COno cout<<"no"<<endl;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define FFOR(i,a,b) for(int i=(a);i<=(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define RREP(i,n)  FFOR(i,1,n)
#define ALL(V) (V).begin(),(V).end()
#define SORT(V) sort((V).begin(),(V).end())
#define REVERSE(V) reverse((V).begin(),(V).end())
#define INF ((1LL<<62)-(1LL<<31))
#define EPS 1e-10
#define PI 3.141592653589793238
#define MOD 1000000007
#define MAX 5100000
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return 1;}return 0;}
const int vx[4]={0,1,0,-1},vy[4]={1,0,-1,0};
using namespace std;

int main(){
  int N,ans=0;
  cin>>N;
  
  vector<ll> A,B,C;
  REP(i,N){
    ll a;
    cin>>a;
    A.push_back(a);
  }
  REP(i,N){
    ll a;
    cin>>a;
    B.push_back(a);
  }
  REP(i,N){
    ll a;
    cin>>a;
    C.push_back(a);
  }
  
  SORT(A);
  SORT(B);
  SORT(C);
  
  REP(i,N){
    auto Iter1=lower_bound(ALL(A),B[i]);
    auto Iter2=upper_bound(ALL(C),B[i]);
    ans+=Iter1*(C.end()-Iter2);
  }
  
  cout<<ans<<endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:74:15: error: no match for 'operator*' (operand types are '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' and '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type' {aka 'long int'})
   74 |     ans+=Iter1*(C.end()-Iter2);
      |          ~~~~~^~~~~~~~~~~~~~~~
      |          |             |
      |          |             __gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type {aka long int}
      |          __gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >
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:1090:7: note: candidate: '__gnu_cxx::__normal_iterator<_Iterator, _Container>::reference __gnu_cxx::__normal_iterator<_Iterator, _Container>::operator*() const [with _Iterator = long long int*; _Container = std::vector<long long int>; reference = long long int&]'
 1090 |       operator*() const _GLIBCXX_NOEXCEPT
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1090:7: note:   candidate expects 0 arguments, 1 provided
In file included from a.cc:16:
/usr/include/c++/14/complex:400:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator*(const complex<_Tp>&, const complex<_Tp>&)'
  400 |     operator*(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:400:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' is not derived from 'const std::complex<_Tp>'
   74 |     ans+=Iter1*(C.end()-Iter2);
      |                              ^
/usr/include/c++/14/complex:409:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator*(const complex<_Tp>&, const _Tp&)'
  409 |     operator*(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:409:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >' is not derived from 'const std::complex<_Tp>'
   74 |     ans+=Iter1*(C.end()-Iter2);
      |                              ^
/usr/include/c++/14/complex:418:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator*(const _Tp&, const complex<_Tp>&)'
  418 |     operator*(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:418:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   mismatched types 'const std::complex<_Tp>' and '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type' {aka 'long int'}
   74 |     ans+=Iter1*(C.end()-Iter2);
      |                              ^