希尔排序

#include <iostream>
using namespace std;
#define  MAXSIZE  20          					
typedef struct
{
	int key;
	char *otherinfo;
}ElemType;
typedef struct
{
    ElemType *r;	         						
    int  length;            						
}SqList;										
void Create_Sq(SqList &L)
{
	int i,n;
	cout<<"请输入数据个数，不超过"<<MAXSIZE<<"个。"<<endl;
	cin>>n;											
	cout<<"请输入待排序的数据:\n";
	while(n>MAXSIZE)
	{
		cout<<"个数超过上限，不能超过"<<MAXSIZE<<"，请重新输入"<<endl;
		cin>>n;
	}
	for(i=1;i<=n;i++)
	{
		cin>>L.r[i].key;
		L.length++;
	}
}
void show(SqList L)
{
	int i;
	for(i=1;i<=L.length;i++)
		cout<<L.r[i].key<<" ";
	cout<<endl;
}
void ShellInsert(SqList &L,int dk,int flag)
{
	int i,j;
	for(i=dk+1;i<=L.length;i++)
	{
		if(L.r[i].key<L.r[i-dk].key)
		{
			L.r[0]=L.r[i];
			for(j=i-dk;;j-=dk)
			{
				if(j>0&&L.r[j].key>L.r[0].key)//和插入排序一样，这里我也是放在里面的。。。
				L.r[j+dk]=L.r[j];
				else
					break;
			}
			L.r[j+dk]=L.r[0];
		}
	}
	cout<<"第 "<<flag++<<" 趟排序 ";
			show(L);
			cout<<endl;		
}//ShellInsert
void ShellSort(SqList &L){
	// 
	int k,flag=1;
    k=L.length;
		do
		{
			k=k/3+1;
			ShellInsert(L,k,flag++);			 		//一趟增量为k的希尔插入排序
        }
		while(k>1);   
}												//ShellSort
void main()
{
	SqList L;
	L.r=new ElemType[MAXSIZE+1];
	L.length=0;
	Create_Sq(L);
	ShellSort(L);
	cout<<"排序后的结果为："<<endl;
	show(L);
}