bzoj1011 [HNOI2008]遥远的行星（分块+瞎搞）

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
#define ll long long
#define inf 0x3f3f3f3f
#define N 100010
#define K 100
inline int read(){
int x=0,f=1;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
return x*f;
}
int n,a
;
double A;
ll sum
;
int main(){
//  freopen("a.in","r",stdin);
n=read();scanf("%lf",&A);
for(int i=1;i<=n;++i) a[i]=read(),sum[i]=sum[i-1]+a[i];
for(int i=1;i<=n;++i){
int r=A*i,l=1;double ans=0;
while(l+K<=r){
ans+=(sum[l+K]-sum[l-1])*1.0/(i-(l+l+K*1.0)/2);l+=K;
}while(l<=r) ans+=a[l]*1.0/(i-l),++l;
printf("%.6lf\n",ans*a[i]);
}
}

#include<iostream>
#include<cstdio>
#include<cmath>
#define eps 1e-8
using namespace std;
int n;
int M[1000005],T=20;
double A,f[1000005];
inline int read()
{
int x=0,f=1;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}
int main()
{
n=read();scanf("%lf",&A);
for(int i=1;i<=n;i++)
M[i]=read();
for(int i=1;i<=T;i++)
{
int r=eps+floor(A*i);
for(int j=1;j<=r;j++)f[i]+=(double)M[i]*M[j]/(i-j);
}
for(int i=T+1;i<=n;i++)
{
int l=eps+floor(A*(i-T));
int r=eps+floor(A*i);
for(int j=l+1;j<=r;j++)f[i]+=(double)M[i]*M[j]/(i-j);
f[i]+=(double)M[i]*(f[i-T]/M[i-T])*(i-T-(double)l/2)/double(i-(double)l/2);
}
for(int i=1;i<=n;i++)
printf("%.6lf\n",f[i]);
return 0;
}