JAVA实现有理数的运算+JAVA中的适配器模式

时间：2022-06-25 10:18:58

题目要求：

设计一个抽象类，声明有关算术运算的方法，并创建四个（或者一个）子类继承该抽象的类，完成进行加、减、乘、除四则运算。

整个题目总共经过了三轮完善，第一发没有利用抽象类，只是简单的实现了基本操作；第二枚用了四个子类去继承这个原有的抽象类，其中就用到了可以骗人的适配器模式，没有实现方法的重写，而是用的方法的重载；第三弹则是用一个子类去继承该抽象类，并重写了其中的抽象方法完成了运算。建议大家直接看第三种！


JAVA中的适配器模式：在学习抽象类的继承和接口的实现时，我们总是要全部重写其中的抽象方法，能不能不这么烦呢，有一种适配器模式，可以巧妙的使用，来达到这个目的。


Aa.java
package cn.nefu.edu.zhihu;

public interface Aa {
	void a();
	void b();

}
Ab.java
package cn.nefu.edu.zhihu;

public class Ab implements Aa{

	public void a() {
		// TODO Auto-generated method stub

	}

	public void b() {
		// TODO Auto-generated method stub

	}

}
Ac.java
package cn.nefu.edu.zhihu;

public class Ac extends Ab{


}

方法一代码： 

Youlishu.java
package cn.nefu.edu.zhihu;

public class Youlishu {
	int fenzi,fenmu;
	Youlishu(){

	}
	Youlishu(int fenzi,int fenmu){
		this.fenzi=fenzi;
		this.fenmu=fenmu;
	}

	int gcd(int x,int y){
		if(y==0)
			return x;
		else
			return gcd(y,x%y);
	}

	int lcm(int x,int y){
		return x*y/gcd(x,y);
	}

	Youlishu add(Youlishu a,Youlishu b){
		Youlishu c=new Youlishu(0,0);
		int d1,d2;
		int lcmm=lcm(a.fenmu,b.fenmu);
		c.fenmu=lcmm;
		d1=lcmm/a.fenmu;
		d2=lcmm/b.fenmu;
		c.fenzi=d1*a.fenzi+d2*b.fenzi;
		int d=gcd(c.fenzi,c.fenmu);
		c.fenzi=c.fenzi/d;
		c.fenmu=c.fenmu/d;
		return c;
	}

	Youlishu sub(Youlishu a,Youlishu b){
		Youlishu c=new Youlishu(0,0);
		int d1,d2;
		int lcmm=lcm(a.fenmu,b.fenmu);
		c.fenmu=lcmm;
		d1=lcmm/a.fenmu;
		d2=lcmm/b.fenmu;
		c.fenzi=d1*a.fenzi-d2*b.fenzi;
		int d=gcd(c.fenzi,c.fenmu);
		c.fenzi=c.fenzi/d;
		c.fenmu=c.fenmu/d;
		return c;
	}

	Youlishu cheng(Youlishu a,Youlishu b){
		Youlishu c=new Youlishu(0,0);
		c.fenzi=a.fenzi*b.fenzi;
		c.fenmu=a.fenmu*b.fenmu;
		int d=gcd(c.fenzi,c.fenmu);
		c.fenzi=c.fenzi/d;
		c.fenmu=c.fenmu/d;
		return c;
	}
	Youlishu chu(Youlishu a,Youlishu b){
		Youlishu c=new Youlishu(0,0);
		c.fenzi=a.fenzi*b.fenmu;
		c.fenmu=a.fenmu*b.fenzi;
		int d=gcd(c.fenzi,c.fenmu);
		c.fenzi=c.fenzi/d;
		c.fenmu=c.fenmu/d;
		return c;
	}
	//getxiaoshu()
	void show(){
		System.out.println(fenzi+"/"+fenmu);
	}

}

Test1.java
package cn.nefu.edu.zhihu;

import java.util.Scanner;

public class test1 {


	public static void main(String[] args) {
		Youlishu a=new Youlishu(2,3);
		Youlishu b=new Youlishu(3,2);
		Youlishu c=new Youlishu(0,0);
		c=c.add(a,b);
		c.show();
		c=c.sub(a,b);
		c.show();
		c=c.cheng(a,b);
		c.show();
		c=c.chu(a,b);
		c.show();
		System.out.println("Please Input Youlishu a and b:");
		Scanner reader=new Scanner(System.in);
		a.fenzi=reader.nextInt();
		a.fenmu=reader.nextInt();
		b.fenzi=reader.nextInt();
		b.fenmu=reader.nextInt();
		c=c.add(a,b);
		c.show();
		c=c.sub(a,b);
		c.show();
		c=c.cheng(a,b);
		c.show();
		c=c.chu(a,b);
		c.show();
	}
}


方法二代码： 

Yunsuan.java
package cn.edu.nefu.zhihu;

public abstract class Yunsuan {
	int gcd(int a,int b){
		if(b==0)
			return a;
		else
			return gcd(b,a%b);
	}
	int lcm(int a,int b){
		return a*b/gcd(a,b);
	}
	abstract Object add(Object a,Object b);
	abstract Object sub(Object a,Object b);
	abstract Object multi(Object a,Object b);
	abstract Object divid(Object a,Object b);
}
Yunsuanzi.java
package cn.edu.nefu.zhihu; //适配器模式

public class Yunsuanzi extends Yunsuan{

	@Override
	Object add(Object a, Object b) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	Object divid(Object a, Object b) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	Object multi(Object a, Object b) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	Object sub(Object a, Object b) {
		// TODO Auto-generated method stub
		return null;
	}
}
Add.java
package cn.edu.nefu.zhihu;

public class Add extends Yunsuanzi {
		Object add(Youlishu a,Youlishu b){
			Youlishu c = new Youlishu(0,0);
			int d1,d2;
			int lcmm=lcm(a.fenmu,b.fenmu);
			c.fenmu=lcmm;
			d1=lcmm/a.fenmu;
			d2=lcmm/b.fenmu;
			c.fenzi=d1*a.fenzi+d2*b.fenzi;
			int d=gcd(c.fenzi,c.fenmu);
			c.fenzi=c.fenzi/d;
			c.fenmu=c.fenmu/d;
			return c;
		}
}
Sub.java
package cn.edu.nefu.zhihu;

public class Sub extends Yunsuanzi{
	Object sub(Youlishu a,Youlishu b){  //注意：方法的重载，不是重写
		Youlishu c=new Youlishu(0,0);
		int d1,d2;
		int lcmm=lcm(a.fenmu,b.fenmu);
		c.fenmu=lcmm;
		d1=lcmm/a.fenmu;
		d2=lcmm/b.fenmu;
		c.fenzi=d1*a.fenzi-d2*b.fenzi;
		int d=gcd(c.fenzi,c.fenmu);
		c.fenzi=c.fenzi/d;
		c.fenmu=c.fenmu/d;
		return c;
	}
}
Multi.java
package cn.edu.nefu.zhihu;

public class Multi extends Yunsuanzi {
	Object multi(Youlishu a,Youlishu b){
		Youlishu c=new Youlishu(0,0);
		c.fenzi=a.fenzi*b.fenzi;
		c.fenmu=a.fenmu*b.fenmu;
		int d=gcd(c.fenzi,c.fenmu);
		c.fenzi=c.fenzi/d;
		c.fenmu=c.fenmu/d;
		return c;
	}
}
Divid.java
package cn.edu.nefu.zhihu;

public class Divid extends Yunsuanzi{
	 Object divid(Youlishu a,Youlishu b){
		Youlishu c=new Youlishu(0,0);
		c.fenzi=a.fenzi*b.fenmu;
		c.fenmu=a.fenmu*b.fenzi;
		int d=gcd(c.fenzi,c.fenmu);
		c.fenzi=c.fenzi/d;
		c.fenmu=c.fenmu/d;
		return c;
	}
}
Youlishu.java
package cn.edu.nefu.zhihu;

public class Youlishu extends Object{
	int fenzi,fenmu;
	Youlishu(){

	}
	Youlishu(int fenzi,int fenmu){
		this.fenzi=fenzi;
		this.fenmu=fenmu;
	}
	void show(){
		System.out.println(fenzi+"/"+fenmu);
	}
}
Test.java
package cn.edu.nefu.zhihu;
import java.util.Scanner;
public class test {

	public static void main(String[] args){
		Scanner reader=new Scanner(System.in);
		int x1,y1,x2,y2;
		x1=reader.nextInt();
		y1=reader.nextInt();
		x2=reader.nextInt();
		y2=reader.nextInt();
		Youlishu ylsa=new Youlishu(x1,y1);
		Youlishu ylsb=new Youlishu(x2,y2);
		Youlishu ylsc=new Youlishu(0,0);
		Add jia=new Add();
		ylsc=(Youlishu) jia.add(ylsa, ylsb);
		ylsc.show();

		Sub jian=new Sub();
		ylsc=(Youlishu) jian.sub(ylsa, ylsb);
		ylsc.show();

		Multi cheng=new Multi();
		ylsc=(Youlishu) cheng.multi(ylsa, ylsb);
		ylsc.show();

		Divid chu=new Divid();
		ylsc=(Youlishu) chu.divid(ylsa, ylsb);
		ylsc.show();
	}
}


方法三代码实现： 

Yunsuan.java
package cn.edu.nefu.zhihu;
public abstract class Yunsuan {
	public abstract Object add(Object a);
	public abstract Object sub(Object a);
	public abstract Object multi(Object a);
	public abstract Object divid(Object a);
	public int gcd(int a,int b){
		if(b==0)
			return a;
		else
			return gcd(b,a%b);
	}
	public int lcm(int a,int b){
		return a*b/gcd(a,b);
	}
}

YouLiShu.java
package cn.edu.nefu.zhihu;

public class YouLiShu extends Yunsuan{
	int fenzi,fenmu;
	public YouLiShu(){}
	public YouLiShu(int fenzi ,int fenmu){
		this.fenzi=fenzi;
		this.fenmu=fenmu;
	}
	@Override
	public YouLiShu add(Object a) {
		YouLiShu y=(YouLiShu)a;
		YouLiShu z=new YouLiShu();
		int lcmm=lcm(fenmu,y.fenmu);
		z.fenmu=lcmm;
		int d1,d2;
		d1=lcmm/fenmu;
		d2=lcmm/y.fenmu;
		z.fenzi=d1*fenzi+d2*y.fenzi;
		int gcdd2=gcd(z.fenmu,z.fenzi);
		z.fenmu=z.fenmu/gcdd2;
		z.fenzi=z.fenzi/gcdd2;
		return z;
	}
	@Override
	public YouLiShu divid(Object a) {
		YouLiShu y=(YouLiShu)a;
		YouLiShu z=new YouLiShu();
		z.fenmu=fenmu*y.fenzi;
		z.fenzi=fenzi*y.fenmu;
		int gcdd2=gcd(z.fenmu,z.fenzi);
		z.fenmu=z.fenmu/gcdd2;
		z.fenzi=z.fenzi/gcdd2;
		return z;
	}
	@Override
	public YouLiShu multi(Object a) {
		YouLiShu y=(YouLiShu)a;
		YouLiShu z=new YouLiShu();
		z.fenmu=fenmu*y.fenmu;
		z.fenzi=fenzi*y.fenzi;
		int gcdd2=gcd(z.fenmu,z.fenzi);
		z.fenmu=z.fenmu/gcdd2;
		z.fenzi=z.fenzi/gcdd2;
		return z;
	}
	@Override
	public YouLiShu sub(Object a) {
		YouLiShu y=(YouLiShu)a;
		YouLiShu z=new YouLiShu();
		z.fenmu=fenmu*y.fenmu;
		z.fenzi=fenzi*y.fenmu-fenmu*y.fenzi;
		int gcdd2=gcd(z.fenmu,z.fenzi);
		z.fenmu=z.fenmu/gcdd2;
		z.fenzi=z.fenzi/gcdd2;
		return z;
	}
	public String toString(){
		return (fenzi+"/"+fenmu);
	}
	public double toXiaoShu(){
		return fenzi*1.0/fenmu;
	}
}
Test.java
package cn.edu.nefu.zhihu;
public class Test {

	public static void main(String[] args) {
		YouLiShu x=new YouLiShu(2,3);//匿名对象
		YouLiShu y=new YouLiShu();
		y=x.add(new YouLiShu(3,2));
		System.out.println(y.toString());
		System.out.println(y.toXiaoShu());
		y=x.sub(new YouLiShu(1,3));
		System.out.println(y.toString());
		System.out.println(y.toXiaoShu());
		y=x.multi(new YouLiShu(1,4));
		System.out.println(y.toString());
		System.out.println(y.toXiaoShu());
		y=x.divid(new YouLiShu(3,2));
		System.out.println(y.toString());
		System.out.println(y.toXiaoShu());
	}
}



标签：

相关文章