数据结构 04 链表 双向链表

#include <stdio.h>
#include <malloc.h>
#include "DLinkList.h"

typedef struct _tag_DLinkList
{
DLinkListNode header;
DLinkListNode* slider;
int length;
} TDLinkList;

DLinkList* DLinkList_Create() // O(1)
{
TDLinkList* ret = (TDLinkList*)malloc(sizeof(TDLinkList));

if( ret != NULL )
{
ret->length = 0;
ret->header.next = NULL;
ret->header.pre = NULL;
ret->slider = NULL;
}

return ret;
}

void DLinkList_Destroy(DLinkList* list) // O(1)
{
free(list);
}

void DLinkList_Clear(DLinkList* list) // O(1)
{
TDLinkList* sList = (TDLinkList*)list;

if( sList != NULL )
{
sList->length = 0;
sList->header.next = NULL;
sList->header.pre = NULL;
sList->slider = NULL;
}
}

int DLinkList_Length(DLinkList* list) // O(1)
{
TDLinkList* sList = (TDLinkList*)list;
int ret = -1;

if( sList != NULL )
{
ret = sList->length;
}

return ret;
}

int DLinkList_Insert(DLinkList* list, DLinkListNode* node, int pos) // O(n)
{
TDLinkList* sList = (TDLinkList*)list;
int ret = (sList != NULL) && (pos >= 0) && (node != NULL);
int i = 0;

if(ret)
{
DLinkListNode* current = (DLinkListNode*)sList;
DLinkListNode* next = NULL;

for(i=0; (i<pos) && (current->next != NULL); i++)
{
current = current->next;
}

next = current->next;

current->next = node;
node->next = next;

if( next != NULL )
{
next->pre = node;
}

node->pre = current;

if( sList->length == 0 )
{
sList->slider = node;
}

if( current == (DLinkListNode*)sList )
{
node->pre = NULL;//修正:如果current指向头结点则node->pre = NULL;
}

sList->length++;
}

return ret;
}

DLinkListNode* DLinkList_Get(DLinkList* list, int pos) // O(n)
{
TDLinkList* sList = (TDLinkList*)list;
DLinkListNode* ret = NULL;
int i = 0;

if( (sList != NULL) && (0 <= pos) && (pos < sList->length) )
{
DLinkListNode* current = (DLinkListNode*)sList;

for(i=0; i<pos; i++)
{
current = current->next;
}

ret = current->next;
}

return ret;
}

DLinkListNode* DLinkList_Delete(DLinkList* list, int pos) // O(n)
{
TDLinkList* sList = (TDLinkList*)list;
DLinkListNode* ret = NULL;
int i = 0;

if( (sList != NULL) && (0 <= pos) && (pos < sList->length) )
{
DLinkListNode* current = (DLinkListNode*)sList;
DLinkListNode* next = NULL;

for(i=0; i<pos; i++)
{
current = current->next;
}

ret = current->next;
next = ret->next;

current->next = next;

if( next != NULL )
{
next->pre = current;

if( current == (DLinkListNode*)sList )
{
next->pre = NULL;
}
}

if( sList->slider == ret )
{
sList->slider = next;
}

sList->length--;
}

return ret;
}

DLinkListNode* DLinkList_DeleteNode(DLinkList* list, DLinkListNode* node)
{
TDLinkList* sList = (TDLinkList*)list;
DLinkListNode* ret = NULL;
int i = 0;

if( sList != NULL )
{
DLinkListNode* current = (DLinkListNode*)sList;

for(i=0; i<sList->length; i++)
{
if( current->next == node )
{
ret = current->next;
break;
}

current = current->next;
}

if( ret != NULL )
{
DLinkList_Delete(sList, i);
}
}

return ret;
}

//使游标指向第一个元素
DLinkListNode* DLinkList_Reset(DLinkList* list)
{
TDLinkList* sList = (TDLinkList*)list;
DLinkListNode* ret = NULL;

if( sList != NULL )
{
sList->slider = sList->header.next;
ret = sList->slider;
}

return ret;
}

DLinkListNode* DLinkList_Current(DLinkList* list)
{
TDLinkList* sList = (TDLinkList*)list;
DLinkListNode* ret = NULL;

if( sList != NULL )
{
ret = sList->slider;
}

return ret;
}

DLinkListNode* DLinkList_Next(DLinkList* list)
{
TDLinkList* sList = (TDLinkList*)list;
DLinkListNode* ret = NULL;

if( (sList != NULL) && (sList->slider != NULL) )
{
ret = sList->slider;
sList->slider = ret->next;
}

return ret;
}

DLinkListNode* DLinkList_Pre(DLinkList* list)
{
TDLinkList* sList = (TDLinkList*)list;
DLinkListNode* ret = NULL;

if( (sList != NULL) && (sList->slider != NULL) )
{
ret = sList->slider;
sList->slider = ret->pre;
}

return ret;
}