#include<cstdio>#include<algorithm>#include<cmath>#include<iostream>#include<cstring>#define LL long long#define MaxN 100005 #define lson l,m,rt<<1#define rson m+1,r,rt<<1|1#define PI (acos(-1.0))struct Point {double x,y;};typedef Point Vector;Point a[500];Point b,c;Vector v1,v2;void updatax(int i){v1.x=(a[i+1].x-a[i].x)/2.0;v1.y=(a[i+1].y-a[i].y)/2.0;double L=sqrt(v1.x*v1.x+v1.y*v1.y);double ll=sqrt(4.0-L*L);v2.x=-v1.y/L*ll;v2.y=v1.x/L*ll;b.x=a[i].x+v1.x+v2.x;b.y=a[i].y+v1.y+v2.y;c.x=a[i].x+v1.x-v2.x;c.y=a[i].y+v1.y-v2.y;if(b.y>c.y){a[i].x=b.x;a[i].y=b.y;}else{a[i].x=c.x;a[i].y=c.y;}}int main(){int tt;scanf("%d",&tt);for(int t=1;t<=tt;t++){int n;scanf("%d",&n);for(int i=0;i<n;i++){scanf("%lf",&a[i].x);a[i].y=1.0;}for(int r=n-1;r>=0;r--)for(int i=0;i<r;i++){updatax(i);}printf("%d: ",t);printf("%.4lf %.4lfn",a[0].x,a[0].y);}}
