Language: C++

#include <iostream>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <map>
#include <queue>
#include <set>
 
static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using namespace std;
 
template<class T>
constexpr T INF = ::numeric_limits<T>::max() / 2 - 170;
 
int main() {
    string s;
    cin >> s;
    int n, x = 0;
    cin >> n;
    for (int i = 'a'; i <= 'z'; ++i) {
        set<string> v;
        for (int j = 0; j < s.length(); ++j) {
            if(s[j] == i){
                for (int k = 1; k <= min(s.length()-j, n); ++k) {
                    v.emplace(s.substr(j, k));
                }
            }
        }
        for (auto &&a : v) {
            x++;
            if(x == n) {
                cout << a << "\n";
                return 0;
            }
        }
    }
    return 0;
}

Compiler output:
a.cc:15:21: error: '::numeric_limits' has not been declared
   15 | constexpr T INF = ::numeric_limits<T>::max() / 2 - 170;
      |                     ^~~~~~~~~~~~~~
a.cc:15:37: error: expected primary-expression before '>' token
   15 | constexpr T INF = ::numeric_limits<T>::max() / 2 - 170;
      |                                     ^
a.cc:15:43: error: no matching function for call to 'max()'
   15 | constexpr T INF = ::numeric_limits<T>::max() / 2 - 170;
      |                                      ~~~~~^~
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:   candidate expects 2 arguments, 0 provided
/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, 0 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, 0 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:   candidate expects 2 arguments, 0 provided
a.cc: In function 'int main()':
a.cc:26:41: error: no matching function for call to 'min(std::__cxx11::basic_string<char>::size_type, int&)'
   26 |                 for (int k = 1; k <= min(s.length()-j, n); ++k) {
      |                                      ~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:233:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::min(const _Tp&, const _Tp&)'
  233 |     min(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:233:5: note:   template argument deduction/substitution failed:
a.cc:26:41: note:   deduced conflicting types for parameter 'const _Tp' ('long unsigned int' and 'int')
   26 |                 for (int k = 1; k <= min(s.length()-j, n); ++k) {
      |                                      ~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::min(const _Tp&, const _Tp&, _Compare)'
  281 |     min(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5686:5: note: candidate: 'template<class _Tp> constexpr _Tp std::min(initializer_list<_Tp>)'
 5686 |     min(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5686:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5696:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::min(initializer_list<_Tp>, _Compare)'
 5696 |     min(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5696:5: note:   template argument deduction/substitution failed:
a.cc:26:41: note:   mismatched types 'std::initializer_list<_Tp>' and 'long unsigned int'
   26 |                 for (int k = 1; k <= min(s.length()-j, n); ++k) {
      |                                      ~~~^~~~~~~~~~~~~~~~~