WA on #4

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=3e5+10;
int n,k,a[N],b[N],l[N],sum[N],ans=0;
signed main(){
	cin>>n>>k;
	for(int i=1;i<=n;i++){
		cin>>b[i];
	}
	for(int i=n;i>=1;i--){
		memset(l,0,sizeof(l));
		if(sum[i]>=b[i])continue;
		int tot=ceil(1.0*(b[i]-a[i])/min(k,i));
		for(int j=i;j>=max(i-k+1,1ll);j--){
			a[j]+=tot;
		}
		for(int j=max(i-k+1,1ll);j<=i;j++){
			l[j]=l[j-1]+a[j];
		}
		for(int j=max(i-k+1,1ll);j<=i;j++){
			sum[j]+=l[j];
		}
		ans+=tot;
	}
	cout<<ans;
	return 0;
}