Question

c++编程。（1）定义父类point，包含x和y两个坐标属性

急，在线等。
（1）定义父类point，包含x和y两个坐标属性，并定义带两参数的构造函数和输出x和y的show函数；（20分）
（2）定义point的公有继承派生类circle，包含半径r一个属性，并定义带三参数的构造函数（其中两参传递给父类）和输出三个属性x,y,r的show函数(要求调用父类的show输出x和 y)。（25分）
（3）主函数测试circle类的构造和输出。（5分）

Answer 1

#include <iostream>

using namespace std;

class point{
public:
    point( double x = 0.0, double y = 0.0 ){
        m_x = x;
        m_y = y;
    }

    void show(){
        cout << "x = " << m_x << "," << "y = " << m_y << endl;
    }

private:
    double m_x;
    double m_y;
};

class circle : public point{
public:
    circle(  double r, double x = 0.0, double y = 0.0)
        : point( x, y){
        m_r = r;
    }

    void show(){
        point::show();
        cout << "r = " << m_r << endl;
    }

private:
    double m_r;
};

int main()
{
    circle dc(100,20,30);
    dc.show();

    return 0;
}

Answer 2

Point类public class Point{private float x;private float y;public Point(float x,float y){this.x = x;this.y = y;}public float getX() {return x;}public void setX(float x) {this.x = x;}public float getY() {return y;}public void setY(float y) {this.y = y;}public float distanceToOrigin(){return (float) Math.sqrt(Math.pow(this.x, 2)+Math.pow(this.y, 2));}public float distanceToOther(int x, int y){return (float) Math.sqrt(Math.pow(this.x-x, 2)+Math.pow(this.y-y, 2));}public float distanceToOther(Point point){return (float) Math.sqrt(Math.pow(this.x-point.x, 2)+Math.pow(this.y-point.y, 2));}}测试类public class TestPoint{public static void main(String[] args) {Point p1 = new Point(3, 5);Point p2 = new Point(7, 8);System.out.println(p1.distanceToOrigin());System.out.println(p2.distanceToOrigin());System.out.println(p1.distanceToOther(20,30));System.out.println(p2.distanceToOther(20,30));System.out.println(p1.distanceToOther(p2));}}

Answer 3

public class Point<T> {
private T x;
private T y;

public Point(T x, T y) {
this.x = x;
this.y = y;
}

public T getX() {
return x;
}

public void setX(T x) {
this.x = x;
}

public T getY() {
return y;
}

public void setY(T y) {
this.y = y;
}

public void outPut(Point<T> p){
System.out.println("点的x坐标为:"+p.getX());
System.out.println("点的y坐标为:"+p.getY());
}

public static void main(String[] args) {
Point<Integer> p=new Point<Integer>(1,2);
p.outPut(p);

Point<Double> d=new Point<Double>(1.0,2.0);
d.outPut(d);

Point<Float> f=new Point<Float>(1.0f,2.0f);
f.outPut(f);

}

}