int main()
{
int N, i, tot, j, num[100];
while(scanf("%d", &N) !=EOF ) {
if(!N)
break;
for(i = 0; i < N; ++i)
scanf("%d", &num[i]);
tot = 0;
for(i = 0; i < N; ++i)
for(j = i+1; j < N; ++j)
if(!has_common(num[i], num[j]))
++tot;
if(tot)
printf("%lf\n", sqrt( 6.0/tot*(N*(N-1)/2)) );
else
printf("No estimate for this data set.\n");
}
return 0;
}
//Intersection point of NURBS and straight line.
MGCCisect_list MGRLBRep::isect(const MGStraight& sline) const{
MGCCisect_list list(this,&sline);
if(!has_common(sline)) return list;
MGCParam_list clist;
double errsave=MGTolerance::wc_zero();
MGTolerance::set_wc_zero(errsave*.3);//make error smaller.
if(sdim()<=2 && sline.sdim()<=2) clist=isect_2D(sline);
else {
MGPlane plane(sline, mgORIGIN);
//The plane that includes sline and passes through the origin.
clist=isect_3D(plane);
}
MGTolerance::set_wc_zero(errsave); //Retrieve error.
MGPosition p; double t1,t2;
MGCParam_list::Citerator i;
for(i=clist.begin(); i!=clist.end(); i++){
t1=(*i); p=eval(t1);
if(sline.on(p,t2)) list.append(MGCCisect(p,t1,t2));
}
return list;
}
