Language: C++

#include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#include<stack>
#include<sstream>
#include<string>
#include<math.h>
using namespace std;

int main()
{
	int a[200000];
	int n;
	cin >> n;
	for (int i = 0; i < n; i++)
	{
		cin >> a[i];
	}
	long long int ans = -9999999999999999999;
	for (int i = 0; i < n; i++)
	{
		for (int s = i + 1; s < n; s++)
		{
			//if (a[s] <= a[i])continue;
			ans = max(a[s] - a[i],ans);
		}
	}
	cout << ans << endl;
}

Compiler output:
a.cc:20:30: warning: integer constant is so large that it is unsigned
   20 |         long long int ans = -9999999999999999999;
      |                              ^~~~~~~~~~~~~~~~~~~
a.cc: In function 'int main()':
a.cc:20:29: warning: overflow in conversion from '__int128' to 'long long int' changes value from '-0x8ac7230489e7ffff' to '8446744073709551617' [-Woverflow]
   20 |         long long int ans = -9999999999999999999;
      |                             ^~~~~~~~~~~~~~~~~~~~
a.cc:26:34: error: no matching function for call to 'max(int, long long int&)'
   26 |                         ans = max(a[s] - a[i],ans);
      |                               ~~~^~~~~~~~~~~~~~~~~
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:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:26:34: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
   26 |                         ans = max(a[s] - a[i],ans);
      |                               ~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: '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:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: '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:5716:5: note:   template argument deduction/substitution failed:
a.cc:26:34: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   26 |                         ans = max(a[s] - a[i],ans);
      |                               ~~~^~~~~~~~~~~~~~~~~