Language: C++

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

signed main(){
  int n; cin >> n;
  n--;
  vector<stirng> now{"a"};
  while(n--){
    vector<string> next;
    for(const auto &S: now){
      char c = *(max_element(S.begin(), S.end()));
      c++;
      for(char d='a'; d<=c; d++){
        next.push_back(S + d);
      }
    }
    now = next;
  }
  
  for(const auto &S: now){
    cout << S << endl;
  }
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:10: error: 'stirng' was not declared in this scope
    7 |   vector<stirng> now{"a"};
      |          ^~~~~~
a.cc:7:16: error: template argument 1 is invalid
    7 |   vector<stirng> now{"a"};
      |                ^
a.cc:7:16: error: template argument 2 is invalid
a.cc:7:22: error: invalid conversion from 'const char*' to 'int' [-fpermissive]
    7 |   vector<stirng> now{"a"};
      |                      ^~~
      |                      |
      |                      const char*
a.cc:10:24: error: 'begin' was not declared in this scope
   10 |     for(const auto &S: now){
      |                        ^~~
a.cc:10:24: note: suggested alternatives:
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166,
                 from a.cc:1:
/usr/include/c++/14/valarray:1238:5: note:   'std::begin'
 1238 |     begin(const valarray<_Tp>& __va) noexcept
      |     ^~~~~
In file included from /usr/include/c++/14/filesystem:53,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:200:
/usr/include/c++/14/bits/fs_dir.h:608:3: note:   'std::filesystem::__cxx11::begin'
  608 |   begin(recursive_directory_iterator __iter) noexcept
      |   ^~~~~
a.cc:10:24: error: 'end' was not declared in this scope
   10 |     for(const auto &S: now){
      |                        ^~~
a.cc:10:24: note: suggested alternatives:
/usr/include/c++/14/valarray:1265:5: note:   'std::end'
 1265 |     end(const valarray<_Tp>& __va) noexcept
      |     ^~~
/usr/include/c++/14/bits/fs_dir.h:613:3: note:   'std::filesystem::__cxx11::end'
  613 |   end(recursive_directory_iterator) noexcept
      |   ^~~
a.cc:17:11: error: cannot convert 'std::vector<std::__cxx11::basic_string<char> >' to 'int' in assignment
   17 |     now = next;
      |           ^~~~
      |           |
      |           std::vector<std::__cxx11::basic_string<char> >
a.cc:20:22: error: 'begin' was not declared in this scope
   20 |   for(const auto &S: now){
      |                      ^~~
a.cc:20:22: note: suggested alternatives:
/usr/include/c++/14/valarray:1238:5: note:   'std::begin'
 1238 |     begin(const valarray<_Tp>& __va) noexcept
      |     ^~~~~
/usr/include/c++/14/bits/fs_dir.h:608:3: note:   'std::filesystem::__cxx11::begin'
  608 |   begin(recursive_directory_iterator __iter) noexcept
      |   ^~~~~
a.cc:20:22: error: 'end' was not declared in this scope
   20 |   for(const auto &S: now){
      |                      ^~~
a.cc:20:22: note: suggested alternatives:
/usr/include/c++/14/valarray:1265:5: note:   'std::end'
 1265 |     end(const valarray<_Tp>& __va) noexcept
      |     ^~~
/usr/include/c++/14/bits/fs_dir.h:613:3: note:   'std::filesystem::__cxx11::end'
  613 |   end(recursive_directory_iterator) noexcept
      |   ^~~