C++实现双向链表

/*
 * DLList.h
 *
 *  Created on: Oct 6, 2015
 *      Author: chris
 */

#ifndef DLLIST_H_
#define DLLIST_H_

typedef int ElemType;

typedef struct DLNode{
	ElemType data;
	DLNode* prior;
	DLNode* next;
}*DLList;

bool DLListCreate(DLList& DLL);
void DLListDestroy(DLList& DLL);

void DLListClear(DLList DLL);
int  DLListLength(DLList DLL);
bool DLListEmpty(DLList DLL);

bool DLListInsert(DLList DLL, int pos, ElemType e);
bool DLListDelete(DLList DLL, int pos, ElemType& e);
bool DLListAppend(DLList DLL, ElemType e);

int  DLListFindElem(DLList DLL, ElemType e);
bool DLListGetElem(DLList DLL, int pos, ElemType& e);

void DLListDisplay(DLList DLL);

void DLListSort(DLList DLL, bool desc);

#endif /* DLLIST_H_ */

/*
 * DLList.cpp
 *
 *  Created on: Oct 6, 2015
 *      Author: chris
 */

#include"DLList.h"
#include<iostream>
#include<cstdlib>

using namespace std;

bool DLListCreate(DLList& DLL)
{
	DLL = new DLNode;
	if(!DLL) return false;
	DLL->prior = DLL->next = NULL;
	return true;
}

void DLListDestroy(DLList& DLL)
{
	DLNode * pcur;
	while(DLL) {
		pcur = DLL;
		DLL = DLL->next;
		delete pcur;
	}
}

void DLListClear(DLList DLL)
{
	DLList sub = DLL->next;
	DLL->next = NULL;
	DLNode *pcur;
	while(sub) {
		pcur = sub;
		sub = sub->next;
		delete pcur;
	}
}

int DLListLength(DLList DLL)
{
	DLNode * pcur = DLL->next;
	int cnt = 0;
	while(pcur) {
		++cnt;
		pcur = pcur->next;
	}
	return cnt;
}

bool DLListEmpty(DLList DLL)
{
	return DLL->next == NULL;
}

bool DLListInsert(DLList DLL, int pos, E