Language: C++

#include<bits/stdc++.h>
using namespace std;

using ll=long long;
using int64=int64_t;
const int inf=100000000;

int in(){
  int a;
  cin >> a;
  return a;
}//int型関数の受け取り

void forin(int* x,int y){
  for (int i=0;i<y;i++){
    cin >> x[i];
  }
}//(x,y) int型配列x[y]の受け取り

int intpow(int x,int y){
  double a=x,b=y;
  return pow(a,b);
}//(x,y) xをy乗

int intfabs(int x){
  double a=x;
  return fabs(a);
}//(x) xの絶対値

int fact(int x){
  if (x == 1) return 1;
  return x*fact(x-1);
}//(x) x!

int fib(int x){
  if (x <= 2) return x;
  int a[x];
  a[0]=1;
  a[1]=2;
  for (int i=2;i<x;i++){
    a[i]=a[i-1]+a[i-2];
  }
  return a[x-1];
}//(x) フィボナッチ数列のx番目

int div1(ll x){
  return x%1000000007;
}

main(){
    int n=in();
    vector<int> a(n),b(n),c(n);
    for (int i=0;i<n;i++) cin >> a[i];
    for (int i=0;i<n;i++) cin >> b[i];
    for (int i=0;i<n;i++) cin >> c[i];
    sort(a.begin(),a.end());
    sort(b.begin(),b.end());
    sort(c.begin(),c.end());
    int ans=0;
    for(int i=0;i<n;i++){
        int t=lower_bound(b.begin(),b.end(),c[i]);
        for (int i2=0;i2<t-b.begin();i2++){
            ans+=lower_bound(a.begin(),t,b[i2])-a.begin();
        }
    }
    cout << ans << endl;
}

Compiler output:
a.cc:50:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   50 | main(){
      | ^~~~
a.cc: In function 'int main()':
a.cc:61:26: error: cannot convert '__gnu_cxx::__normal_iterator<int*, std::vector<int> >' to 'int' in initialization
   61 |         int t=lower_bound(b.begin(),b.end(),c[i]);
      |               ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
      |                          |
      |                          __gnu_cxx::__normal_iterator<int*, std::vector<int> >
a.cc:62:27: error: no match for 'operator-' (operand types are 'int' and 'std::vector<int>::iterator')
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                          ~^~~~~~~~~~
      |                          |        |
      |                          int      std::vector<int>::iterator
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: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:62:36: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'int'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/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:62:36: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'int'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
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:62:36: note:   mismatched types 'const std::complex<_Tp>' and 'int'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/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:62:36: note:   mismatched types 'const std::complex<_Tp>' and 'int'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/usr/include/c++/14/complex:388:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const _Tp&, const complex<_Tp>&)'
  388 |     operator-(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:388:5: note:   template argument deduction/substitution failed:
a.cc:62:36: note:   'std::vector<int>::iterator' is not derived from 'const std::complex<_Tp>'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/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:62:36: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/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:62:36: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/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:62:36: note:   'std::vector<int>::iterator' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/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:62:36: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/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:62:36: note:   'std::vector<int>::iterator' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/usr/include/c++/14/valarray:1197:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__minus, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__minus, _Tp>::result_type> std::operator-(const valarray<_Tp>&, const valarray<_Tp>&)'
 1197 | _DEFINE_BINARY_OPERATOR(-, __minus)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1197:1: note:   template argument deduction/substitution failed:
a.cc:62:36: note:   mismatched types 'const std::valarray<_Tp>' and 'int'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/usr/include/c++/14/valarray:1197:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__minus, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__minus, _Tp>::result_type> std::operator-(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1197 | _DEFINE_BINARY_OPERATOR(-, __minus)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1197:1: note:   template argument deduction/substitution failed:
a.cc:62:36: note:   mismatched types 'const std::valarray<_Tp>' and 'int'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/usr/include/c++/14/valarray:1197:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__minus, _Tp>::result_type> std::operator-(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1197 | _DEFINE_BINARY_OPERATOR(-, __minus)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1197:1: note:   template argument deduction/substitution failed:
a.cc:62:36: note:   'std::vector<int>::iterator' is not derived from 'const std::valarray<_Tp>'
   62 |         for (int i2=0;i2<t-b.begin();i2++){
      |                                    ^
/us