较水。

单调队列扫一遍即可。

#include
    
     using namespace std;typedef int INT;#define int long longconst int N=4e6+500;inline char nc(){    static char buf[100000],*p1=buf,*p2=buf;    return p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++;}inline void read(int &x){	x=0;	int f=1;	char ch=nc();	while(ch<'0'||ch>'9'){		if(ch=='-')			f=-1;		ch=nc();	}	while(ch>='0'&&ch<='9'){		x=x*10+ch-'0';		ch=nc();	}	x*=f;}int n,p,d;int a[N]={};int sum[N]={};int g[N]={};int q[N]={};int head,tail;INT main(){	read(n);	read(p);	read(d);	for(int i=1;i<=n;i++){		read(a[i]);		sum[i]=sum[i-1]+a[i];	}	for(int i=0;i<=n;i++){		if(i+d>n)			g[i]=sum[n]-sum[i];		else g[i]=sum[i+d]-sum[i];	}	q[1]=0;	head=1;	tail=1;	int ans=d,idx=0;	for(int i=d+1;i<=n;i++){		while(head<=tail&&g[q[tail]]<=g[i-d])tail--;		tail++;		q[tail]=i-d;//		idx=0;		while(head<=tail&&idx
     
      <(sum[i]-sum[idx]-g[q[head]])){ 			idx++;			while(q[head]