POJ2069 最小球体覆盖, 模拟退火

只是套了个模板，模拟退火具体的过程真心不懂阿

 //#pragma comment(linker, "/STACK:16777216") //for c++ Compiler
 #include <stdio.h>
 #include <iostream>
 #include <cstring>
 #include <cmath>
 #include <stack>
 #include <queue>
 #include <vector>
 #include <algorithm>
 #define ll long long
 #define Max(a,b) (((a) > (b)) ? (a) : (b))
 #define Min(a,b) (((a) < (b)) ? (a) : (b))
 #define Abs(x) (((x) > 0) ? (x) : (-(x)))
 using namespace std;

 const int INF = 0x3f3f3f3f;
 const int MAXN = ;
 const double eps = 1e-;
 int n;
 struct POINT{
     double x,y,z;
 }ps[],q;

 double dist(POINT a,POINT b){
     return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y)+(a.z-b.z)*(a.z-b.z));
 }

 int maxD(POINT p){
     double res = ;
     int i, k = ;
     for(i = ; i < n ; ++i){
         double tmp = dist(p,ps[i]);
         if(tmp > res){
             k = i;
             res = dist(p,ps[i]);
         }
     }
     return k;
 }

 double BallCover(){
     double step = , ans = INF;
     q.x = q.y = q.z = 0.0;
     while(step > eps){
         int d = maxD(q);
         double tmp = dist(ps[d],q);
         if(tmp < ans) ans=tmp;
         double dx = ps[d].x - q.x;
         double dy = ps[d].y - q.y;
         double dz = ps[d].z - q.z;
         dx /= tmp;
         dy /= tmp;
         dz /= tmp;
         q.x += (dx*step);
         q.y += (dy*step);
         q.z += (dz*step);
         step *= 0.98;
     }
     return ans;
 }

 int main(){
     int i;
     while(EOF != scanf("%d",&n)){
         if( == n)  break;
         for(i = ; i < n ; ++i)
             scanf("%lf%lf%lf",&ps[i].x,&ps[i].y,&ps[i].z);
         printf("%.5f\n",BallCover());
     }
     return ;
 }