我真的红温了啊
#include <bits/stdc++.h>
using namespace std;
const int N = 3e5+10,INF = 0x3f3f3f3f;
int a[N],f[N],n,l,r,ans=-INF;
deque<int> q;
signed main()
{
cin >> n >> l >> r;
for(int i=0;i<=n;i++) cin >> a[i];
memset(f,-INF,sizeof(f));
f[0] = 0;
for(int i=l;i<=n;i++)
{
while(!q.empty() && f[q.back()]<=f[i]) q.pop_back();
q.push_back(i-l);
while(!q.empty() && q.front()+r<i) q.pop_front();
f[i] = f[q.front()]+a[i];
if(i+r>n) ans = max(ans,f[i]);
}
cout << ans;
return 0;
}