ポリシーモードC++実装

#include<iostream>

#include<algorithm>

#include<string>

/*

    ：          ？ 

*/ 

using namespace std;

/*abstract sort class --- strategy class*/

class super_sort

{ public:

  typedef int ElemType;

  void swap(ElemType *a,ElemType*b)

      {

        ElemType tmp;

        tmp=*a;

        *a=*b;

        *b=tmp;

       }

        

    

  virtual void sort(int *a,int l, int r)

  { }    

};



/* concrete sort --- concret strategy */



/*quicksort*/

class quick_sort: public super_sort

{ private: 

  typedef int ElemType;



int partition(int *a,int l,int r)

{ElemType v=a[r];

 int i=l-1;int j=r;

 while(i<j)

 {

 while(a[++i]>v&&i<r) ;

 while(j>l&&a[--j]<v) ;

 if(i>=j)  

   break;

  swap(&a[i],&a[j]);

 }

  swap(&a[i],&a[r]);

  

 return i;

}



void quicksort(int *a,int l,int r)

{ int i;

  if(l>=r) return;

  i=partition(a,l,r);

  quicksort(a,l,i-1);

  quicksort(a,i+1, r);

   

}

 public: 

  void sort(int *a, int l, int r)

  {

    quicksort(a,l,r);

         

  }    

    

};



/*insert sort*/ 



class insert_sort: public super_sort

{

  private:

  typedef int ElemType;

  void insertsort(ElemType *a,int l,int r) 

  {

    int i;

     for(i=1;i<r;i++)

	    if(a[i]<a[0]) swap(&a[0],&a[i]);

	     

	    for(i=l+2;i<r;i++)

	    {

	      int j=i;ElemType v=a[i];

		  while(v<a[j-1])

		  {a[j]=a[j-1];j--;}

		   a[j]=v;

	  

	     }

  }

  

  public:

        void sort(int *a,int l, int r)

        {

            insertsort(a,l,r);

        }  

};



/*direct sort*/



class direct_sort: public super_sort

{

  private:

void selectsort(int *a,int l,int r)

{int i,j;

 int flag=1;

  for(i=l;i<r;i++)

 {   int min=i;

	 for(j=i+1;j<10;j++)

	 {   

		 if(a[j]<a[min])

               min=j;

			   

	 }

	 swap(&a[i],&a[min]);

	 

 }

}

 

 public:

     void sort(int *a, int l, int r)

     {

          selectsort(a,l,r);  

     }    

            

};



/*context class*/



class context

{ 

  private:

  super_sort *my_sort;

  public:

     context(){};   

     void select_sort(int num,int *a, int l, int r)

     {

       switch(num)

       {

         case 1:

                my_sort = new quick_sort();

                break;    

        case 2:

            my_sort = new insert_sort();

            break;

        case 3:

            my_sort = new direct_sort();

            break;

        

        default:

            cout << "Erro input, please check. " << endl;

            

        }

        my_sort->sort(a, l, r); 

     }

     

    void sort_list()

    {

      cout <<"1 -------- quicksort ---------"<< endl;    

      cout <<"2 -------- insertsort ---------"<< endl;

      cout <<"3 -------- directsort ---------"<< endl;

      cout << "Input your choice: "<< endl;

    }

};



/*

                    ：

                  ，               ；

        。

               

*/



/*client class*/

int main()

{   int num;

    int a[10] = {1,20,12,0,4,54,22,11,78,8};

    context my_selection;

    my_selection.sort_list();

    cin >> num;

    my_selection.select_sort(num,a,0,9);

    cout <<"-------- result ---------"<< endl;

    for(int i = 0; i < 10; i++)

      cout <<a[i]<< endl;

    

   system("pause"); 

   return 0;    

}