Language: C++

#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;


int N, K;
long long a[5002];

bool dp[5003][5000];

bool is_needed(int x){
    for(int k = 0; k < K; k++){
            dp[0][k] = false;
    }
    dp[0][0] = true;
    for(int i = 0; i < N; i++){
        for(int k = 0; k < K; k++){
            dp[i+1][k] = dp[i][k];
        }
        if(i != x){
           for(int k = 0; k < K; k++){
               if(a[i] + k < K){
                   dp[i+1][a[i]+k] = dp[i][k] || dp[i+1][a[i]+k];
               }
           }
        }
    }
    bool ret = false;
    for(int k = max(0, K - a[x]); k < K; k++){
        ret = ret || dp[N][k];
    }
    return ret;
}

// is_needed(begin) == false, is_needed(end) == true
int find(int begin, int end){
    if(end - begin == 1){
        return begin;
    }
    int mid = (begin + end)/2;
    if(is_needed(mid)){
        return find(begin, mid);
    }else{
        return find(mid, end);
    }
}

int main(){
    cin >> N >> K;
    for(int i = 0; i < N; i++){
        cin >> a[i];
    }
    sort(a, a+N);
    if(is_needed(0) == true){
        cout << 0 << endl;
        return 0;
    }
    if(is_needed(N-1) == false){
        cout << N << endl;
        return 0;
    }
    cout << find(0, N-1) + 1 << endl;
}

Compiler output:
a.cc: In function 'bool is_needed(int)':
a.cc:30:20: error: no matching function for call to 'max(int, long long int)'
   30 |     for(int k = max(0, K - a[x]); k < K; k++){
      |                 ~~~^~~~~~~~~~~~~
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:30:20: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
   30 |     for(int k = max(0, K - a[x]); k < K; k++){
      |                 ~~~^~~~~~~~~~~~~
/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:3:
/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:30:20: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   30 |     for(int k = max(0, K - a[x]); k < K; k++){
      |                 ~~~^~~~~~~~~~~~~