Vector operator / (Vector A,double p){ return Vector(A.x/p,A.y/p); }

这是一个重载运算符，表示将一个向量 A 的每个分量除以一个标量 p，并返回一个新的向量。

具体来说，这段代码定义了一个名为 "/" 的运算符，它接受两个参数：一个是 Vector 类型的对象 A，另一个是 double 类型的标量 p。

这个运算符的实现是将向量 A 的 x 分量和 y 分量都除以 p，然后返回一个新的 Vector 对象，这个对象的 x 分量和 y 分量分别为 A.x/p 和 A.y/p。

注意，这里使用了 Vector 类的构造函数来创建新的 Vector 对象。

相关问题

#include<cstdio> #include<cstring> #include<algorithm> #include<cmath> using namespace std; const int maxn=10000+5; const double eps=1e-10; int dcmp(double x) { if(fabs(x)<eps) return 0; return x<0?-1:1; }struct Point { double x,y; int id; Point(){} Point(double x,double y,int id):x(x),y(y),id(id){} }P[maxn]; typedef Point Vector; Vector operator-(Point A,Point B) { return Vector(A.x-B.x,A.y-B.y,0); }double Cross(Vector A,Vector B) { return A.x*B.y-A.y*B.x; }bool cmp(Point A,Point B) { return dcmp(Cross(A-P[0],B-P[0]))<0; }int main() { int n; while(scanf("%d",&n)==1) { scanf("%lf%lf",&P[0].x,&P[0].y); P[0].id=1; for(int i=1;i<n;++i) { scanf("%lf%lf",&P[i].x,&P[i].y); P[i].id=i+1; if(P[i].x<P[0].x || (P[i].x==P[0].x && P[i].y<P[0].y) ) swap(P[0],P[i]); }sort(P+1,P+n,cmp); printf("%d %d\n",P[0].id,P[n/2].id); }return 0; }转为Java代码

import java.util.*;
import java.io.*;

class Main {
static final double eps = 1e-10;
static int n;
static Point[] P = new Point[10000 + 5];

static class Point {
double x, y;
int id;

public Point() {}

public Point(double x, double y, int id) {
this.x = x;
this.y = y;
this.id = id;
}
}

static int dcmp(double x) {
if (Math.abs(x) < eps) return 0;
return x < 0 ? -1 : 1;
}

static class Vector {
double x, y;

public Vector(double x, double y) {
this.x = x;
this.y = y;
}
}

static Vector minus(Point A, Point B) {
return new Vector(A.x - B.x, A.y - B.y);
}

static double Cross(Vector A, Vector B) {
return A.x * B.y - A.y * B.x;
}

static boolean cmp(Point A, Point B) {
return dcmp(Cross(minus(A, P[0]), minus(B, P[0]))) < 0;
}

public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNext()) {
n = sc.nextInt();
P[0] = new Point(sc.nextDouble(), sc.nextDouble(), 1);
for (int i = 1; i < n; ++i) {
P[i] = new Point(sc.nextDouble(), sc.nextDouble(), i + 1);
if (P[i].x < P[0].x || (P[i].x == P[0].x && P[i].y < P[0].y))
swap(P, 0, i);
}
Arrays.sort(P, 1, n, Main::cmp);
System.out.println(P[0].id + " " + P[n / 2].id);
}
}

static void swap(Point[] P, int i, int j) {
Point temp = P[i];
P[i] = P[j];
P[j] = temp;
}
}

class Vector3 { public: Vector3(); Vector3(double x,double y,double z); public: Vector3 operator+(const Vector3 &A)const; Vector3 operator++(); friend Vector3 operator-(const Vector3 &v1, const Vector3 &v2); friend Vector3 operator--(Vector3 &v); void display()const; private: double m_x; double m_y; double m_z; }; Vector3::Vector3() :m_x(0.0), m_y(0.0), m_z(0.0) {} Vector3::Vector3(double x, double y,double z) : m_x(x), m_y(y), m_z(z) {} //运算符重载 Vector3 Vector3::operator+(const Vector3 &A) const { Vector3 B; B.m_x = this->m_x + A.m_x; B.m_y = this->m_y + A.m_y; B.m_z = this->m_z + A.m_z; return B; } Vector3 Vector3::operator++() { this->m_x ++; this->m_y ++; this->m_z ++; return *this; } void Vector3::display()const { cout<<"(" << m_x << "," << m_y << "," << m_z << ")" << endl; } Vector3 operator-(const Vector3 &v1,const Vector3 &v2) { Vector3 B(v1.m_x - v2.m_x, v1.m_y - v2.m_y, v1.m_z - v2.m_z); return B; } Vector3 operator--( Vector3 &v) { v.m_x--; v.m_y--; v.m_z --; return v; } int main() { Vector3 v1(1, 2, 3); Vector3 v2(2, 3, 2); ++v1;//v1.operator++(); 作为类成员函数可以显式调用 v1.display(); --v2; v2.display(); Vector3 v3 = v1 + v2;// v1.operator+(v2);作为类成员函数可以显式调用 v3.display(); Vector3 v4 = v1 - v2; v4.display(); return 0; }分析一下这段代码，可以将两个友元函数改为类成员函数吗？

可以将两个友元函数改为类成员函数，具体实现如下：

class Vector3 { 
public: 	
    Vector3(); 	
    Vector3(double x,double y,double z); 
    Vector3 operator+(const Vector3 &A)const; 	
    Vector3 operator++(); 	
    Vector3 operator--(); 
    Vector3 operator-(const Vector3 &A) const;
    void display() const; 
private: 	
    double m_x; 	
    double m_y; 	
    double m_z; 
}; 

Vector3 Vector3::operator+(const Vector3 &A) const { 
    Vector3 B; 	
    B.m_x = this->m_x + A.m_x; 	
    B.m_y = this->m_y + A.m_y; 	
    B.m_z = this->m_z + A.m_z; 	
    return B; 
} 

Vector3 Vector3::operator++() { 
    this->m_x ++; 	
    this->m_y ++; 	
    this->m_z ++; 	
    return *this; 
} 

Vector3 Vector3::operator--() { 
    this->m_x --; 	
    this->m_y --; 	
    this->m_z --; 	
    return *this; 
} 

Vector3 Vector3::operator-(const Vector3 &A) const { 
    Vector3 B; 	
    B.m_x = this->m_x - A.m_x; 	
    B.m_y = this->m_y - A.m_y; 	
    B.m_z = this->m_z - A.m_z; 	
    return B; 
} 

void Vector3::display() const { 
    cout << "(" << m_x << "," << m_y << "," << m_z << ")" << endl; 
}

其中，将 `operator-` 和 `operator--` 改为了成员函数，并且将 `operator-` 的参数名改为了 `A`，来避免与 `operator--` 的参数名冲突。