Language: C++

#include<bits/stdc++.h>
#include<cstdio>

#define ll long long int

int main(){
  int n;
  vector<int> h;
  int i;

  cin >> n;
  for(i=0;i<n;i++){
    int ah;
    h.emplace_back(ah);
  }

  int dp[n];

  for(i=0;i<n;i++){
    dp[i]=1;
    if(h[i] > h[j]){
      dp[i] = max(dp[i], dp[j] + 1);
    }
  }

  	
  int ans = 0;
  for(i=0;i<N;i++){
    ans = max(ans, dp[i]);
  }
  cout << ans << endl;

}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:3: error: 'vector' was not declared in this scope
    8 |   vector<int> h;
      |   ^~~~~~
a.cc:8:3: note: suggested alternatives:
In file included from /usr/include/c++/14/vector:66,
                 from /usr/include/c++/14/functional:64,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_vector.h:428:11: note:   'std::vector'
  428 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
/usr/include/c++/14/vector:93:13: note:   'std::pmr::vector'
   93 |       using vector = std::vector<_Tp, polymorphic_allocator<_Tp>>;
      |             ^~~~~~
a.cc:8:10: error: expected primary-expression before 'int'
    8 |   vector<int> h;
      |          ^~~
a.cc:11:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
   11 |   cin >> n;
      |   ^~~
      |   std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:14:5: error: 'h' was not declared in this scope; did you mean 'ah'?
   14 |     h.emplace_back(ah);
      |     ^
      |     ah
a.cc:21:8: error: 'h' was not declared in this scope
   21 |     if(h[i] > h[j]){
      |        ^
a.cc:21:17: error: 'j' was not declared in this scope
   21 |     if(h[i] > h[j]){
      |                 ^
a.cc:22:15: error: 'max' was not declared in this scope; did you mean 'std::max'?
   22 |       dp[i] = max(dp[i], dp[j] + 1);
      |               ^~~
      |               std::max
In file included from /usr/include/c++/14/algorithm:61,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51:
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: 'std::max' declared here
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
a.cc:28:13: error: 'N' was not declared in this scope
   28 |   for(i=0;i<N;i++){
      |             ^
a.cc:29:11: error: 'max' was not declared in this scope; did you mean 'std::max'?
   29 |     ans = max(ans, dp[i]);
      |           ^~~
      |           std::max
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: 'std::max' declared here
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
a.cc:31:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   31 |   cout << ans << endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:31:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   31 |   cout << ans << endl;
      |                  ^~~~
      |                  std::endl
In file included from /usr/include/c++/14/istream:41,
                 from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~