PROG-1157: ส่งกระแสไฟฟ้า (electricity)_ priority queue

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

using pii = pair<int,int>;
int dp[500001];
priority_queue <pii,vector<pii>,greater<pii>> pq;

void del(int i,int k){
    while(pq.size() > 0 and i-pq.top().second > k) {
        pq.pop();
    }
}

int main(){

    int n,k;
    scanf("%d%d",&n,&k);

    int ar[n+1];
    for(int i=1;i<=n;i++) scanf("%d",&ar[i]);

    dp[1] = ar[1];
    pq.push({dp[1],1});

    for(int i=2;i<=n;i++){
        del(i,k);
        dp[i] = ar[i] + pq.top().first;
        pq.push({dp[i],i});
    }
    printf("%d",dp[n]);

    return 0;
}