Language: C++

#include<bits/stdc++.h>

using namespace std;

#define int long long
#define ALL(x) (x).begin(),(x).end()
#define MAX(x) *max_element(ALL(x))
#define MIN(x) *min_element(ALL(x))

typedef pair<int,int> PI;
typedef pair<int,pair<int,int>> PII;
static const int INF=1010000000000000017LL;
static const double eps=1e-12;
static const double pi=3.14159265358979323846;
static const int dx[4]={1,-1,0,0};
static const int dy[4]={0,0,1,-1};
static const int ddx[8]={1,-1,0,0,1,1,-1,-1};
static const int ddy[8]={0,0,1,-1,1,-1,1,-1};

template<class T> inline bool chmin(T& a,T b){if(a>b){a=b;return true;}return false;}
template<class T> inline bool chmax(T& a,T b){if(a<b){a=b;return true;}return false;}

template<typename T>
struct Vector2 {
    T x, y;
    Vector2() {}
    Vector2(T x, T y) : x(x), y(y) {}
    void operator=(const Vector2 &other) {
        x = other.x;
        y = other.y;
    }
    Vector2 operator+(const Vector2 &other) {
        return Vector2I(x + other.x, y + other.y);
    }
    Vector2 operator-(const Vector2 &other) {
        return Vector2I(x - other.x, y - other.y);
    }
    bool operator==(const Vector2 &other) {
        return (x == other.x && y == other.y);
    }
    int dot(Vector2 other) {
        return x * other.x + y * other.y;
    }
    int det(Vector2 other) {
        return x * other.y - y * other.x;
    }
};

template<typename T>
bool cmp_x(const Vector2<T> &p, const Vector2<T> &q) {
    if(p.x != q.x) return p.x < q.x;
    return p.y < q.y;
}

template<typename T>
vector<T> convexhull(vector<T> &ps) {
    sort(ps.begin() , ps.end(), cmp_x<T>);
    int size = ps.size();
    int k = 0;
    if (size <= 2) return ps;
    vector<Vector2<T>> qs(size * 2);
    for (int i = 0; i < size; ++i) {
        while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
        qs[k++] = ps[i];
    }
    for (int i = size - 2, t = k; i >= 0; i--) {
        while(k > t && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
        qs[k++] = ps[i];
    }
    qs.resize(k - 1);
    return qs;
}

int N;
vector<Vector2<int>> P;

signed main(){
    cin>>N;
    for(int i=0;i<N;++i){
        int x,y;
        cin>>x>>y;
        P.push_back(Vector2(x,y));
    }
    auto qs=convexhull(P);
    int ans=0;
    for(int i=0;i<qs.size()-1;++i){
        for(int j=i+1;j<qs.size();++j){
            int d=abs(qs[i].x-qs[j].x)+abs(qs[i].y-qs[j].y);
            chmax(ans,d);
        }
    }
    cout<<ans<<endl;
}

Compiler output:
a.cc: In instantiation of 'std::vector<_Tp> convexhull(std::vector<_Tp>&) [with T = Vector2<long long int>]':
a.cc:84:23:   required from here
   84 |     auto qs=convexhull(P);
      |             ~~~~~~~~~~^~~
a.cc:63:59: error: no match for 'operator-' (operand types are '__gnu_cxx::__alloc_traits<std::allocator<Vector2<long long int> >, Vector2<long long int> >::value_type' {aka 'Vector2<long long int>'} and '__gnu_cxx::__alloc_traits<std::allocator<Vector2<Vector2<long long int> > >, Vector2<Vector2<long long int> > >::value_type' {aka 'Vector2<Vector2<long long int> >'})
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
a.cc:35:13: note: candidate: 'Vector2<T> Vector2<T>::operator-(const Vector2<T>&) [with T = long long int]'
   35 |     Vector2 operator-(const Vector2 &other) {
      |             ^~~~~~~~
a.cc:35:38: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<Vector2<Vector2<long long int> > >, Vector2<Vector2<long long int> > >::value_type' {aka 'Vector2<Vector2<long long int> >'} to 'const Vector2<long long int>&'
   35 |     Vector2 operator-(const Vector2 &other) {
      |                       ~~~~~~~~~~~~~~~^~~~~
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:63:59: note:   '__gnu_cxx::__alloc_traits<std::allocator<Vector2<long long int> >, Vector2<long long int> >::value_type' {aka 'Vector2<long long int>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
/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:63:59: note:   '__gnu_cxx::__alloc_traits<std::allocator<Vector2<long long int> >, Vector2<long long int> >::value_type' {aka 'Vector2<long long int>'} is not derived from 'const std::move_iterator<_IteratorL>'
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
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:63:59: note:   '__gnu_cxx::__alloc_traits<std::allocator<Vector2<long long int> >, Vector2<long long int> >::value_type' {aka 'Vector2<long long int>'} is not derived from 'const std::complex<_Tp>'
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
/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:63:59: note:   '__gnu_cxx::__alloc_traits<std::allocator<Vector2<long long int> >, Vector2<long long int> >::value_type' {aka 'Vector2<long long int>'} is not derived from 'const std::complex<_Tp>'
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
/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:63:59: note:   '__gnu_cxx::__alloc_traits<std::allocator<Vector2<Vector2<long long int> > >, Vector2<Vector2<long long int> > >::value_type' {aka 'Vector2<Vector2<long long int> >'} is not derived from 'const std::complex<_Tp>'
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
/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:63:59: note:   '__gnu_cxx::__alloc_traits<std::allocator<Vector2<long long int> >, Vector2<long long int> >::value_type' {aka 'Vector2<long long int>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
/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:63:59: note:   '__gnu_cxx::__alloc_traits<std::allocator<Vector2<long long int> >, Vector2<long long int> >::value_type' {aka 'Vector2<long long int>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
/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:63:59: note:   '__gnu_cxx::__alloc_traits<std::allocator<Vector2<Vector2<long long int> > >, Vector2<Vector2<long long int> > >::value_type' {aka 'Vector2<Vector2<long long int> >'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
/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:63:59: note:   '__gnu_cxx::__alloc_traits<std::allocator<Vector2<long long int> >, Vector2<long long int> >::value_type' {aka 'Vector2<long long int>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   63 |         while (k > 1 && (qs[k - 2] - qs[k - 1]).det(ps[i] - qs[k - 1]) <= 0) k--;
      |                                                     ~~~~~~^~~~~
/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)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~