最小球覆盖，使用模拟退火

#include<iostream>
#include<math.h>
using namespace std;
const double eps=1e-8;
struct point{double x,y,z;} p[(int)1e5+5];
int n,pos;
double T,delta=0.99,r,ans;
double sq(double x){return x*x;}
point c;
double dis(point a,point b){return sqrt(sq(a.x-b.x)+sq(a.y-b.y)+sq(a.z-b.z));}
double solve(){
T=100.0;
c=p[0];
while(T>eps){
pos=0,r=0;
for(int i=0;i<n;i++)
if(dis(c,p[i])>r) r=dis(c,p[i]),pos=i;
c.x+=(p[pos].x-c.x)/r*T;
c.y+=(p[pos].y-c.y)/r*T;
c.z+=(p[pos].z-c.z)/r*T;
T*=delta;
}
return r;
}
int main(){
while(cin>>n){
if(n==0)break;
// cin>>n;
for(int i=0;i<n;i++)cin>>p[i].x>>p[i].y>>p[i].z;
// for(int i=0;i<n;i++)cout<<p[i].x<<p[i].y<<p[i].z;
ans=solve();
printf("%.5f\n",ans);
}
return 0;
}