[bzoj] 1011: [HNOI2008]遥远的行星

http://www.cnblogs.com/CtrlCV/p/5615585.html,还可以用这种方法?

#include <cstdio>using namespace std;double m[100005], sum[100005];int n;double a, ans;int main(){    register int i,j,k;    scanf("%d %lf",&n,&a);    for(j=1;j<=n;j++)    {        int i=(int)(a*j+1e-8);        scanf("%lf",m+j);        ans=0;        if(j<=500)            for(k=1;k<=i;k++)            ans+=m[k]*m[j]/(j-k);        else ans=sum[i]*m[j]/(j-i/2);        printf("%f\n",ans);        sum[j]=sum[j-1]+m[j];    }    return 0;}