hdu1115求凸包重心

题目链接：点击打开链接

用模板就好了

#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;
const int maxn=1e6+10;
struct Point//点 向量
{
    double x,y;
    Point(double x=0,double y=0):x(x),y(y) {}
};
typedef  Point  Vector;
//向量使用点作为表示方法 结构相同 为了代码清晰
const double eps = 1e-8;

int dcmp(double x) //三态函数 处理与double零有关的精度问题
{
    if(fabs(x) < eps)    return 0;
    return x<0 ? -1 : 1;
}
//向量运算
Vector operator + (Vector A, Vector B)
{
    return Vector(A.x+B.x, A.y+B.y);
}
Vector operator - (Vector A, Vector B)
{
    return Vector(A.x-B.x, A.y-B.y);
}
Vector operator * (Vector A, double p)
{
    return Vector(A.x*p, A.y*p);
}
Vector operator / (Vector A, double p)
{
    return Vector(A.x/p, A.y/p);
}
bool operator == (const Vector& A, const Vector& B)
{
    return dcmp(A.x-B.x)==0 && dcmp(A.y-B.y)==0;
}
bool operator < (const Point&a,const Point &b)
{
    return a.x