#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#define ll long long
using namespace std;
const int N=5505;
ll f[N][N],a[N];
int q[N];
int main(){
	//freopen("5858.in","r",stdin);
	//freopen("5858.out","w",stdout);
	int n,w,s;
	scanf("%d%d%d",&n,&w,&s);
	for(int i=1;i<=n;i++)scanf("%lld",&a[i]);
	for(int i=0;i<=n;i++)for(int j=0;j<=n;j++)f[i][j]=-1e18;
	f[0][0]=0;
	for(int i=1;i<=n;i++){
		int l=0,r=0,kdl=0;
		memset(q,0,sizeof(q));
		for(int j=1;j<=min(i,w);j++){
			while(kdl<=min(w,j-1+s)){
				while(l<=r&&q[l]<j-1)l++;
				while(l<=r&&f[i-1][q[r]]<=f[i-1][kdl])r--;
				q[++r]=kdl;
				kdl++;
			}
			f[i][j]=f[i-1][q[l]]+1ll*a[i]*j;
			/*for(int k=j-1;k<=min(w,j-1+s);k++)
				f[i][j]=max(f[i][j],f[i-1][k]+1ll*a[i]*j);*/
		}
	}
	/*for(int i=0;i<=n;i++){
		for(int j=0;j<=n;j++)printf("%d ",f[i][j]);
		printf("\n");
	}*/
	ll ans=-1e18;
	for(int i=1;i<=w;i++)ans=max(ans,f[n][i]);
	printf("%lld\n",ans);
	return 0;
} 

找了大半天错没找出来QWQ

想知道单调队列到底哪里写挂了

貌似样例中有负数就会挂