【BZOJ1011】遥远的行星

  当我知道这道题是估算的时候我的内心几乎是崩溃的...

#include <cstdio>
#include <algorithm>
using namespace std;
typedef long long LL;
const double eps=1e-8;
 
int M[100010];
int n;
double A;
 
int main()
{
    scanf("%d%lf",&n,&A);
    int k=0;LL sum=0;
    for (int i=1;i<=min(n,2000);i++)
    {
        double ans=0;
        scanf("%d",&M[i]);
        if (k+1<=A*i+eps) k++,sum+=M[k];
        for (int j=1;j<=k;j++)
            ans+=(double)M[i]*(double)M[j]/(double)(i-j);
        printf("%f\n",ans);
    }
     
    for (int i=2001;i<=n;i++)
    {
        scanf("%d",&M[i]);
        if (k+1<=A*i+eps) k++,sum+=M[k];
        double p=(double)1.0/(i-k/2);
        printf("%f\n",p*(double)M[i]*(double)sum);
    }
    return 0;
}