Language: C++

#include<iostream>
#include <string.h> 
using namespace std;
#define M 1046527
#define NIL (-1)
#define L 14

char H[M][L];

// ??????????????°????????????
int getChar(char ch){
    if(ch == 'A') return 1;
    else if(ch == 'B') return 2;
    else if(ch == 'C') return 3;
    else if(ch == 'D') return 4;
    else return 0;
}
// ?????????????????°??????????????????key?????????
long long getKey(char str[]){
    long long sum = 0, p = 1;
    for(int i = 0; i < strlen(str); i++){
        sum += p*(getChar(str[i]));
        p *= 5;
    }
    return sum;
}

int h1(int key){
    return key % M;
}
int h2(int key){
    return 1 + (key % (M-1));
}

int find(char str[]){
    long long key, i, h;
    key = getKey(str);
    for(int i = 0;; i++){
        h = (h1(key) + i*h2(key)) % M;
        if(strcmp(H[h],str) == 0)
            return 1;
        else if(strlen(H[h]) == 0)
            return 0;
    }
}

int insert(char str[]){
    long long key, i, h;
    key = getKey(str);
    for(int i = 0;; i++){
        h = (h1(key) + i*h2(key)) % M;
        if(strcmp(H[h],str) == 0)
            return 1;
        else if(strlen(H[h]) == 0){
            strcpy(H[h], str);
            return 0;
        }
    }
}
int main(){
    int n;
    char command[9], str[L];
    for(int i = 0; i < M; i++) H[i][0] = '?\0';
    cin >> n;
    while(n--){
        cin >> command >> str;
        if(command[0] == 'i'){
            insert(str);
        }else if(command[0] == 'f'){
            if(find(str))
                cout << "YES" << endl;
            else
                cout << "NO" < endl;
        }
    }
}

Compiler output:
a.cc:63:42: warning: multi-character character constant [-Wmultichar]
   63 |     for(int i = 0; i < M; i++) H[i][0] = '?\0';
      |                                          ^~~~~
a.cc: In function 'int main()':
a.cc:63:42: warning: overflow in conversion from 'int' to 'char' changes value from '16128' to '0' [-Woverflow]
a.cc:73:30: error: no match for 'operator<' (operand types are 'std::basic_ostream<char>' and '<unresolved overloaded function type>')
   73 |                 cout << "NO" < endl;
      |                 ~~~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/14/string:48,
                 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_iterator.h:448:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  448 |     operator<(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:448:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
/usr/include/c++/14/bits/stl_iterator.h:493:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  493 |     operator<(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:493:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
/usr/include/c++/14/bits/stl_iterator.h:1694:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1694 |     operator<(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1694:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'const std::move_iterator<_IteratorL>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
/usr/include/c++/14/bits/stl_iterator.h:1760:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1760 |     operator<(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1760:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'const std::move_iterator<_IteratorL>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/string:51:
/usr/include/c++/14/bits/stl_pair.h:1045:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator<(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1045 |     operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1045:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'const std::pair<_T1, _T2>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:673:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  673 |     operator< (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:673:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
/usr/include/c++/14/string_view:680:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  680 |     operator< (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:680:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
/usr/include/c++/14/string_view:688:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  688 |     operator< (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:688:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   couldn't deduce template parameter '_CharT'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
/usr/include/c++/14/bits/basic_string.h:3874:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3874 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3874:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
/usr/include/c++/14/bits/basic_string.h:3888:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3888 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3888:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
/usr/include/c++/14/bits/basic_string.h:3901:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3901 |     operator<(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3901:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
In file included from /usr/include/c++/14/bits/memory_resource.h:47,
                 from /usr/include/c++/14/string:68:
/usr/include/c++/14/tuple:2600:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator<(const tuple<_UTypes ...>&, const tuple<_Elements ...>&)'
 2600 |     operator<(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/usr/include/c++/14/tuple:2600:5: note:   template argument deduction/substitution failed:
a.cc:73:32: note:   'std::basic_ostream<char>' is not derived from 'const std::tuple<_UTypes ...>'
   73 |                 cout << "NO" < endl;
      |                                ^~~~
In file included from /usr/include/c++/14/bits/ios_base.h:46:
/usr/include/c++/14/system_error:324:3: note: candidate: 'bool std::operator<(const error_code&, const error_code&)'
  324 |   operator<(const error_code& __lhs, const error_code& __rhs) noexcept
      |   ^~~~~~~~
/usr/include/c++/14/system_error:324:31: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'const std::error_code&'
  324 |   operator<(const error_code& __lhs, const error_code& __rhs) noexcept
      |             ~~~~~~~~~~~~~~~~~~^~~~~
/usr/include/c++/14/system_error:507:3: note: candidate: 'bool std::operator<(const error_condition&, const error_condition&)'
  507 |   operator<(const error_condition& __lhs,
      |   ^~~~~~~~
/usr/include/c++/14/system_error:507:36: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'const std::error_condition&'
  507 |   operator<(const error_condition& __lhs,
      |             ~~~~~~~~~~~~~~~~~~~~~~~^~~~~