双向带头链表
双向链表也叫双链表,是链表的一种,它的每个数据结点中都有两个指针,分别指向直接后继和直接前驱。所以,从双向链表中的任意一个结点开始,都可以很方便地访问它的前驱结点和后继结点。一般我们都构造双向循环链表。
实现代码如下:
带头双向循环链表:
接口:
#include<stdio.h>
#include<stdlib.h>
#include<assert.h>
#include<string.h>
#include<malloc.h>
typedef int LTDataType;
typedef struct ListNode
{
LTDataType _data;
struct ListNode* _next;
struct ListNode* _prev;
}ListNode;
typedef struct List
{
ListNode* _head;
}List;
void ListInit(List* plist); //创建一个链表
void ListDestory(List* plist); //消除一个链表
void ListPushBack(List* plist, LTDataType x); //尾插
void ListPopBack(List* plist); //尾删
void ListPushFront(List* plist, LTDataType x); //头插
void ListPopFront(List* plist); //头删
ListNode* ListFind(List* plist, LTDataType x); //查找
// 在pos的前面进行插入
void ListInsert(ListNode* pos, LTDataType x);
// 删除pos位置的节点
void ListErase(ListNode* pos);
void ListRemove(List* plist, LTDataType x); //移除
int ListSize(List* plist); //节点个数
int ListEmpty(List* plist); // 清空
void ListReverse(List* plist); //相反链表
void ListPrint(List* plist);
接口具体实现:
ListNode*BuyListNode(LTDataType x)
{
ListNode* node = (ListNode*)malloc(sizeof(ListNode));
node->_data = x;
node->_next = NULL;
node->_prev = NULL;
return node;
}
void ListInit(List* plist) //构建链表
{
ListNode* head = BuyListNode(-1);
assert(plist);
head->_next = head;
head->_prev = head;
plist->_head = head;
}
void ListDestory(List* plist) //判断链表
{
ListNode* head = plist->_head;
ListNode* cur = head->_next;
ListNode* next = NULL;
assert(plist);
while (cur != head)
{
next = cur->_next;
free(cur);
cur = cur->_next;
}
free(head);
head = NULL;
}
void ListPushBack(List* plist, LTDataType x) //尾插
{
ListNode*head = plist->_head;
ListNode* tail = head->_prev;
ListNode* newnode = BuyListNode(x);
assert(plist);
tail->_next = newnode;
newnode->_prev = tail;
newnode->_next = head;
head->_prev = newnode;
}
void ListPopBack(List* plist) //尾删
{
ListNode*head = plist->_head;
ListNode* tail = head->_prev;
ListNode* tailprev = tail->_prev;
assert(plist);
free(tail);
tailprev->_next = head;
head->_prev = tailprev;
}
void ListPushFront(List* plist, LTDataType x) //头插
{
ListNode*head = plist->_head;
ListNode* next = head->_next;
ListNode* newnode = BuyListNode(x);
assert(plist);
head->_next = newnode;
newnode->_next = next;
newnode->_prev = head;
next->_prev = newnode;
}
void ListPopFront(List* plist) //头删
{
ListNode* head = plist->_head;
ListNode* next = head->_next;
ListNode* nextnext = next->_next;
assert(plist);
free(next);
head->_next = nextnext;
nextnext->_prev = head;
}
ListNode* ListFind(List* plist, LTDataType x) //查找
{
ListNode* head = plist->_head;
ListNode* cur = head->_next;
assert(plist);
while (cur != head)
{
if (cur->_data == x)
{
return cur;
}
cur = cur->_next;
}
return cur;
}
// 在pos的前面进行插入
void ListInsert(ListNode* pos, LTDataType x)
{
ListNode* prev = pos->_prev;
ListNode* newnode = BuyListNode(x);
assert(pos);
newnode->_next = pos;
pos->_prev = newnode;
prev->_next = newnode;
newnode->_prev = prev;
}
// 删除pos位置的节点
void ListErase(ListNode* pos)
{
ListNode* prev = pos->_prev;
ListNode* next = pos->_next;
assert(pos);
free(pos);
prev->_next = next;
next->_prev = prev;
}
void ListRemove(List* plist, LTDataType x) //移除
{
ListNode* node = ListFind(plist, x);
assert(plist);
if (node != plist->_head)
{
ListErase(node);
}
}
int ListSize(List* plist) //节点个数
{
int size = 0;
ListNode* cur = plist->_head->_next;
assert(plist);
while (cur != plist->_head)
{
size++;
cur = cur->_next;
}
printf("%d", size);
return size;
}
int ListEmpty(List* plist) //清空链表
{
assert(plist);
printf("%d", plist->_head->_next == plist->_head ? 0 : -1);
return 0;
}
void ListReverse(List* plist) //反向链表
{
ListNode* head = plist->_head;
ListNode* cur = head->_next;
ListNode* tmp = NULL;
assert(plist);
while (cur != plist->_head)
{
tmp = cur->_next;
cur->_next = cur->_prev;
cur->_prev = tmp;
cur = cur->_prev;
}
tmp = head->_next;
head->_next = head->_prev;
head->_prev = tmp;
}
void ListPrint(List* plist)
{
ListNode* head = plist->_head;
ListNode* cur = head->_next;
assert(plist);
while (cur != head)
{
printf("<-%d->", cur->_data);
cur = cur->_next;
}
printf("\n");
}
以上就是关于带头双向循环链表的实现代码,关于无头单向不循环的实习代码可大家可以看我的博客:
链表—单链表