#include "stdafx.h"
#include <malloc.h>
typedef char ElemType;
typedef struct DNode
{
	ElemType data;
	struct DNode * prior;
	struct DNode * next;
}DLinkList;
void InintList(DLinkList * &L)
{
	L = (DLinkList *)malloc(sizeof(DLinkList));
	L->next = L->prior = NULL;
}
void DestroyList(DLinkList * &L)
{
	DLinkList *p = L;
	DLinkList *q = p->next;
	while (q!=NULL)
	{
		free(p);
		p = q;
		q = p->next;
	}
	free(p);
}
int ListEmpty(DLinkList *L)
{
	return(L->next == NULL);
}
int ListLength(DLinkList *L)
{
	DLinkList *p = L;
	int i = 0;
	while (p->next!=NULL)
	{
		i++;
		p = p->next;
	}
	return i;
}
void DispList(DLinkList *L)
{
	DLinkList *p = L->next;
	while (p!=NULL)
	{
		printf_s("%c", p->data);
		p = p->next;
	}
	printf_s("\n");
}
int GetElem(DLinkList *L,int i,ElemType &e)
{
	int j = 0;
	DLinkList *p = L;
	while (p!=NULL && j<i)
	{
		p = p->next;
		j++;
	}
	if (p == NULL)
	{
		return 0;
	}
	e = p->data;
	return 1;
}
int LocateElem(DLinkList *L, ElemType e)
{
	int j = 0;
	DLinkList *p = L->next;
	while (p!=NULL && p->data!=e )
	{
		j++;
		p = p->next;
	}
	if (p == NULL)
	{
		return 0;
	}
	else
	{
		return j;
	}
}
int ListInsert(DLinkList * &L, int i, ElemType e)
{
	/*
		找到第i个元素的前一个元素
		不存在第i个元素则为NULL返回0
		找到第i个元素，则进行创建节点插入操作，返回0，
	*/
	int j = 0;
	DLinkList *p = L;
	DLinkList *s;
	while (p!=NULL &&j<i-1)
	{
		p = p->next;
		j++;
	}
	if (p == NULL)
	{
		return 0;
	}
	else
	{
		s = (DLinkList *)malloc(sizeof(DLinkList));
		s->data = http://www.mamicode.com/e;>