java：，

java：，

在只知道矩形中心，矩形长宽的情况下，

1.涉及如何判定一个点是否在一个矩形里。

2.判定一个矩形在另一个矩形里，也是只知道中心坐标和长宽。

3.判定一个矩形和另一个矩形相交，条件也如上。

设计一个java-MyRectangle2D类。

附两份代码，都是可以的，有些许细节用法不同。

public class Exercise10_12 {

    public static void main(String[] args) {
        MyRectangle2D r1 =new MyRectangle2D(2,2,5.5,4.9);
        System.out.println("(3,3)是否在r1中：" +r1.contains(3, 3));
        System.out.println("(4,5,10.5,3.2)是否在r1中：" +r1.contains(new MyRectangle2D(4, 5, 10.5, 3.2)));
        System.out.println("(3, 5, 2.3, 5.4)是否与r1重叠：" +r1.overlaps(new MyRectangle2D(3,5,2.3,5.4)));
        
    }
    
}
class MyRectangle2D{
    private double x;
    private double y;
    private double width;
    private double height;
    public double GETx(){
        return x;
    }
    public double GETy(){
        return y;
    }
    public double GETw(){
        return width;
    }
    public double GETh(){
        return height;
    }
    public void SETw(double new_width){
        width=new_width;
    }
    public void SETh(double new_height){
        height = new_height;
    }
    public MyRectangle2D(){
        x = 0;
        y = 0;
        width = 1;
        height = 1;
    }
    public MyRectangle2D(double new_x,double new_y,double width,double height) {
        x = new_x;
        y = new_y;
        SETw(width);
        SETh(height);
    }
    public double getAreac(){
        return width*height;
    }
    public double Get_Perimeter(){
        return (width+height)*2;
    }
    public boolean contains(double x,double y){
        if(x <(this.x+width/2)&&(this.x-width/2)< x&&y<(this.y+height/2)&&y>(this.y-height/2)){
            return true;
        }
         else
        {
            return false;
        }
    }
    public boolean contains(MyRectangle2D r){
        if(r.GETx()<(this.x+(width-r.GETw())/2)&&(this.x-(width-r.GETw())/2)< r.GETw()&&r.GETy()<(this.y+(height-r.GETh())/2)&&r.GETy()>(this.y+(height-r.GETh())/2)){
            return true;
        }
         else
        {
            return false;
        }
    }
    public boolean overlaps(MyRectangle2D r){
        if(r.GETx()<(this.x+(width+r.GETw())/2)&&(this.x-(width+r.GETw())/2)< r.GETw()&&r.GETy()<(this.y+(height+r.GETh())/2)&&r.GETy()>(this.y+(height+r.GETh())/2)){
            return true;
        }
         else
        {
            return false;
        }
    }
}

public class Exercise10_12 {
  public static void main(String[] args) {
    MyRectangle2D r1 = new MyRectangle2D(2, 2, 5.5, 4.9);
    System.out.println("Area is " + r1.getArea());
    System.out.println("Perimeter is " + r1.getPerimeter());
    System.out.println(r1.contains(3, 3));
    System.out.println(r1.contains(new MyRectangle2D(4, 5, 10.5, 3.2)));
    System.out.println(r1.overlaps(new MyRectangle2D(3, 5, 2.3, 6.7)));
  }
}

class MyRectangle2D {
  private double x, y; // Center of the rectangle
  private double width, height;
  
  public MyRectangle2D() {
    x = y = 0;
    width = height = 1;
  }
  
  public MyRectangle2D(double x, double y, double width, double height) {
    this.x = x;
    this.y = y;
    this.width = width;
    this.height = height;
  }
  
  public double getX() {
    return x;
  }
  
  public void setX(double x) {
    this.x = x;
  }

  public double getY() {
    return y;
  }

  public void setY(double y) {
    this.y = y;
  }
  
  public double getWidth() {
    return width;
  }

  public void setWidth(double width) {
    this.width = width;
  }
  
  public double getHeight() {
    return height;
  }

  public void setHeight(double height) {
    this.height = height;
  }
  
  public double getPerimeter() {
    return 2 * (width + height);
  }
  
  public double getArea() {
    return width * height;
  }
  
  public boolean contains(double x, double y) {
    return Math.abs(x - this.x) <= width / 2 &&
      Math.abs(y - this.y) <= height / 2;
  }
  
  public boolean contains(MyRectangle2D r) {    
    return contains(r.x - r.width / 2, r.y + r.height / 2) &&
      contains(r.x - r.width / 2, r.y - r.height / 2) &&
      contains(r.x + r.width / 2, r.y + r.height / 2) &&
      contains(r.x + r.width / 2, r.y - r.height / 2);
  }
  
  public boolean overlaps(MyRectangle2D r) {    
    return Math.abs(this.x - r.x) <= (this.width + r.width) / 2 &&
      Math.abs(this.y - r.y) <= (this.height + r.height) / 2; 
  }