原题链接https://www.luogu.com.cn/problem/P8656

动态规划 贪心

#include <bits/stdc++.h>

#define ll long long

const ll N = 1e6;

ll op[N];
ll dp[N];
bool ok[N];

std::map<ll,ll> pp;//统计每个数出现的次数

int main(){
    ll n,k;
    std::cin >> n >> k;
    ll ans = 0;
    for(ll i = 1; i <= n; i ++){
        ll a;
        std::cin >> a;
        ans = std::max(ans,a);
        op[a] ++;
    }
    if(k == 0){
        ll res = 0;
        for(ll i = 0; i <= ans; i ++){
            if(op[i]) res ++; 
        }
        std::cout << res << "\n";
        return 0;
    }
    for(ll i = 0; i <= ans; i ++){
        if(op[i] < op[i + k]) op[i + k] -= op[i];
        else op[i + k] = 0;
    }
    ll res = 0;
    for(ll i = 0; i <= ans; i ++) res += op[i];
    std::cout << res << "\n";
    return 0;
}