hdu 4068 福州赛区网络赛A 数学 ***

 1 #include<cstdio>
 2 #include<iostream>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<queue>
 7 #include<map>
 8 using namespace std;
 9 #define MOD 1000000007
10 const int INF=0x3f3f3f3f;
11 const double eps=1e-5;
12 typedef long long ll;
13 #define cl(a) memset(a,0,sizeof(a))
14 #define ts printf("*****\n");
15 const int MAXN=1005;
16 int n,m,tt;
17 int a[MAXN];
18 int main()
19 {
20     int i,j,k,ca=1;
21     #ifndef ONLINE_JUDGE
22     freopen("1.in","r",stdin);
23     #endif
24     scanf("%d",&tt);
25     while(tt--)
26     {
27         cin>>n;
28         int w,sum=0;
29         printf("Case %d: ",ca++);
30         for(i=0;i<n;i++)
31         {
32             int a;
33             scanf("%d",&a);
34             if(i==0)    w=a;
35             sum+=a;
36         }
37         printf("%.6lf\n",(double)w/sum);
38     }
39 }