HDU 5035 Delivery

公式题

概率论书上原题

这是最详细的公式推导

https://www.zybuluo.com/rihkddd/note/34286

#include<cstdio>#include<cstring>#include<iostream>using namespace std;double a[1001];int main(){int T,n,cas=1;scanf("%d",&T);while(T--){double sum=0;scanf("%d",&n);for(int i=0;i<n;i++){scanf("%lf",&a[i]);sum+=a[i];}for(int i=0,temp;i<n;i++)scanf("%d",&temp);printf("Case #%d: %.6f\n",cas++,(n+1.0)/sum);}return 0;}