高飞实验16和17

package shiyan16;

public abstract class AbstractCommand {    
      public abstract int execute(int value);     
      public abstract int undo();    
    }    

package shiyan16;

 
public class Adder {    
private int num=0;   
    

public int add(int value) {    
    num += value;    
    return num;    
}    
}    

package shiyan16;

public class CalculatorForm {    
    private AbstractCommand command;    
        
    public void setCommand(AbstractCommand command) {    
        this.command = command;    
    }    
  
    public void compute(int value) {    
        int i = command.execute(value);    
        System.out.println("执行后结果为：" + i);    
    }    
        
   
    public void undo() {    
        int i = command.undo();    
        System.out.println("撤销后结果为：" + i);    
    }    
} 

package shiyan16;

public class Client {    
    public static void main(String args[]) {    
        CalculatorForm form = new CalculatorForm();    
        AbstractCommand command;    
        command = new ConcreteCommand();    
        form.setCommand(command); 
            
        form.compute(1);    
        form.compute(2);    
        form.compute(3);    
        form.undo();  
        form.undo();
        form.undo();
    }    
}    

package shiyan16;

 
public class ConcreteCommand extends AbstractCommand {    
private Adder adder = new Adder();    
private int value;  

public int execute(int value) {    
        this.value=value;    
        return adder.add(value);    
    }    
        
    
    public int undo() {    
        return adder.add(-value);    
    }    
}    

 

实验18

#include <iostream>  

#include<string>

#include <sstream>

#include <vector>  

using namespace std;



/* object可以是任意类型的变量 */

typedef int object;



class Iterator

{

public:

    virtual object begin() = 0;

    virtual void   next() = 0;

    virtual object end() = 0;

    virtual object current() = 0;

    virtual bool   IsDone() = 0;

};



class ConcreteAggregate

{

private:

    vector<object> _objects;



public:

    void AddObject(object obj)

    {

        _objects.push_back(obj);

    }



    object& operator[](int index)

    {

        return _objects[index];

    }

    int size()

    {

        return _objects.size();

    }

};



class ConcreteIterator :public Iterator

{

public:

    ConcreteAggregate* agg;

    int _index;

public:

    ConcreteIterator(ConcreteAggregate* agg)

    {

        this->agg = agg;

        _index = 0;

    }

    virtual object begin()

    {

        return (*agg)[0];

    }

    virtual void next()

    {

        _index++;

    }

    virtual void preious()

    {

        _index--;

    }



    virtual object end()

    {

        _index = agg->size();

        return (*agg)[_index - 1];

    }



    virtual object current()

    {

        return (*agg)[_index];

    }



    virtual bool IsDone()

    {

        return (_index == agg->size());

    }

    virtual bool IsFirst()

    {

        return (_index == 0);

    }

};



int main()

{

    ConcreteAggregate* objects = new ConcreteAggregate();

    cout << "信1305班同学:" << endl;

    for (int i = 1; i <= 44; i++)

    {

        int m = 20130000 + i;

        objects->AddObject(m);

        m = 0;

    }



    ConcreteIterator* iter = new ConcreteIterator(objects);

    ConcreteIterator* iter1 = new ConcreteIterator(objects);



    object tmp_begin = iter->begin();

    cout << "从小到大输出:" << endl;

    while (!iter->IsDone())

    {

        cout << iter->current() << endl;

        iter->next();

    }

    cout << endl;



    object tmp_begin1 = iter1->end();

    cout << "从大到小输出:" << endl;

    while (!iter1->IsFirst())

    {

        iter1->preious();

        cout << iter1->current() << endl;

    }

    cout << endl;



    delete objects;

    delete iter;



    system("pause");

    return 0;
}