Language: C++

#include<iostream>
#include<algorithm>
using namespace std;
static const int max = 200000;

int main(){
  int R[max], n;

  cin >> n;
  for ( int i = 0; i <n ; i++ ) cin >> R[i];

  int maxv = -200000000;
  int minv = R[0];

  for ( int i = 1; i < n; i++ ) {
    maxv = max(maxv, R[i] - minv);
    minv = min(minv, R[i]);
  }

  cout << maxv << endl;

  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:9: error: reference to 'max' is ambiguous
    7 |   int R[max], n;
      |         ^~~
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidates are: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:                 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
In file included from /usr/include/c++/14/string:51,
                 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_algobase.h:303:5: note:                 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:                 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
a.cc:4:18: note:                 'const int max'
    4 | static const int max = 200000;
      |                  ^~~
a.cc:10:40: error: 'R' was not declared in this scope
   10 |   for ( int i = 0; i <n ; i++ ) cin >> R[i];
      |                                        ^
a.cc:13:14: error: 'R' was not declared in this scope
   13 |   int minv = R[0];
      |              ^
a.cc:16:12: error: reference to 'max' is ambiguous
   16 |     maxv = max(maxv, R[i] - minv);
      |            ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidates are: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:                 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:                 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:                 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
a.cc:4:18: note:                 'const int max'
    4 | static const int max = 200000;
      |                  ^~~