poj_2069_Super Star_WA

#include<iostream>    #include<sstream>    #include<string>    #include<vector>    #include<list>    #include<set>    #include<map>  #include<stack>    #include<queue>    #include<algorithm>    #include<numeric>    #include<cmath>  #include<cstdio>  #include<cstdlib>  #include<cstring>#include<ctime>#pragma warning(disable:4996) const double EPS = 1e-15;const double rate = 0.9995;#define INF 2000000000#define PI acos(-1.0)const int N = 30;const int M = 30;using namespace std;class Point{public:double x, y, z;};double dist(const Point &p1, const Point &p2){return sqrt((p1.x - p2.x)*(p1.x - p2.x) + (p1.y - p2.y)*(p1.y - p2.y) + (p1.z - p2.z)*(p1.z - p2.z));}double getMaxDist(const Point&p, const vector<Point>&point){double ans = 0.0;for (size_t i = 0; i != point.size(); i++){ans = max(ans, dist(p, point[i]));}return ans;}int main(){//freopen("input.txt", "r", stdin);//freopen("output.txt", "w", stdout);srand((unsigned)time(NULL));int n;while (cin >> n&&n){vector<Point>point(n);double max_x = -2000000000.0, max_y = -2000000000.0, max_z = -2000000000.0;double min_x = 2000000000.0, min_y = 2000000000.0, min_z = 2000000000.0;for (int i = 0; i < n; i++){cin >> point[i].x >> point[i].y >> point[i].z;max_x = max(max_x, point[i].x);max_y = max(max_y, point[i].y);max_z = max(max_z, point[i].z);min_x = min(min_x, point[i].x);min_y = min(min_y, point[i].y);min_z = min(min_z, point[i].z);}Point curpoint;curpoint.x = (max_x - min_x) / 2.0;curpoint.y = (max_y - min_y) / 2.0;curpoint.z = (max_z - min_z) / 2.0;double delta = 100;double ans = getMaxDist(curpoint, point);while (delta > 1e-15){double theta1 = (double)(rand() % 1000) / 1000.0*2.0*PI;double theta2 = (double)(rand() % 1000) / 1000.0*2.0*PI;Point nextpoint;nextpoint.x = curpoint.x + cos(theta1)*cos(theta2)*delta;nextpoint.y = curpoint.y + cos(theta1)*sin(theta2)*delta;nextpoint.z = curpoint.z + sin(theta1)*delta;double distance = getMaxDist(nextpoint, point);if (distance < ans){curpoint = nextpoint;ans = distance;}delta *= rate;}printf("%.5lf\n", ans);}return 0;}