AC
```c
#include <iostream>
#include <cstring>
using namespace std;
#define Max 1000001
typedef long long int ll;
ll a[Max];
ll sum[Max];
ll M=-Max;
int main()
{
ios::sync_with_stdio(false);
ll n,k,t=0;
cin>>n>>k;
for(ll i=1;i<n;i++)
{
cin>>a[i];
t+=a[i];
sum[i]=sum[i-1]+a[i];
}
for(int i=k;i<=n;i++)
{
ll f=sum[i]-sum[i-k];
M=max(f,M);
}
ll res=t-M;
cout<<res<<endl;
}
```
by timmyliao @ 2024-01-26 11:07:26
谢大佬
by zzh1109 @ 2024-01-26 11:09:38