{ }soj.1206

#include<stdio.h>#include<math.h>#include<algorithm>using namespace std;int main(){ int n,i,t,cases=1; double a[1005],x,y; scanf("%d",&t); while(t--) { scanf("%d",&n);  for(i=0;i<n;i++)        scanf("%lf",&a[i]);        sort(a,a+n);  y=1.0;  for (i=1; i<n; i++)        y+=sqrt(4-(a[i]-a[i-1])*(a[i]-a[i-1])/4);  printf("%d: %.4lf %.4lf\n",cases++,(a[0]+a[n-1])/2,y); } return 0;}