思路：
代码：
代码语言：javascript复制#include<bits/stdc .h>
using namespace std;
#define int long long
const int N=1e5 10;
int n,k,a[N],f[N];
int get(int x){
if(x==0)return 0;
return f[x-1]-a[x];
}
signed main(){
cin>>n>>k;
for(int i=1;i<=n;i )cin>>a[i],a[i] =a[i-1];
deque<int>q;
q.push_front(0);
for(int i=1;i<=n;i ){
if(!q.empty()&&i-q.front()>k)q.pop_front();
f[i]=max(f[i-1],a[i] get(q.front()));
while(!q.empty()&&get(q.back())<=get(i))q.pop_back();
q.push_back(i);
}
cout<<f[n]<<endl;
}
