C语言实现带头双向循环链表的接口

本文实例为大家分享了C语言实现带头双向循环链表的接口，供大家参考，具体内容如下

各函数功能如下

申请空间

ListNode* BuyListNode(LTDataType x)
{
 ListNode* node = (ListNode*)malloc(sizeof(ListNode));
 node->next = NULL;
 node->prev = NULL;
 node->data = x;
 return node;
}

初始化

ListNode* ListInit()
{
 ListNode* phead = BuyListNode(0);
 phead->next = phead;
 phead->prev = phead;

 return phead;
}

指定位置插入

void ListInsert(ListNode* pos, LTDataType x)
{
 assert(pos);

 ListNode* prev = pos->prev;
 ListNode* newnode = BuyListNode(x);
 prev->next = newnode;
 newnode->prev = prev;
 newnode->next = pos;
 pos->prev = newnode;
}

头插

void ListPushFront(ListNode* phead, LTDataType x)
{
 //assert(phead);
 //ListNode* first = phead->next;
 //ListNode* newnode = BuyListNode(x);
 phead newnode first
 //phead->next = newnode;
 //newnode->prev = phead;
 //newnode->next = first;
 //first->prev = newnode;

 ListInsert(phead->next, x);//实现了指定位置插入后，可以套用
}

尾插

void ListPushBack(ListNode* phead, LTDataType x)
{
 //assert(phead);
 //ListNode* tail = phead->prev;
 //ListNode* newnode = BuyListNode(x);

 //tail->next = newnode;
 //newnode->prev = tail;
 //newnode->next = phead;
 //phead->prev = newnode;

 ListInsert(phead, x);
}

指定位置删除

void ListErase(ListNode* pos)
{
 assert(pos);

 ListNode* prev = pos->prev;
 ListNode* next = pos->next;

 prev->next = next;
 next->prev = prev;

 free(pos);
}

头删

void ListPopFront(ListNode* phead)
{
 //assert(phead);
 //assert(phead->next != phead);

 //ListNode* first = phead->next;
 //ListNode* second = first->next;

 //free(first);

 //phead->next = second;
 //second->prev = phead;

 ListErase(phead->next);
}

尾删

void ListPopBack(ListNode* phead)
{
 //assert(phead);
 //assert(phead->next != phead);

 //ListNode* tail = phead->prev;
 //ListNode* tailPrev = tail->prev;
 //free(tail);

 //tailPrev->next = phead;
 //phead->prev = tailPrev;

 ListErase(phead->prev);

}

查找

ListNode* ListFind(ListNode* phead, LTDataType x)
{
 assert(phead);

 ListNode* cur = phead->next;
 while (cur)
 {
  if (cur->data == x)
  {
   return cur;
  }
  cur = cur->next;
 }

 return NULL;
}

判空

int ListEmpty(ListNode* phead)
{
 assert(phead);
 return phead->next == phead ? 1 : 0;
}

元素个数

int ListSize(ListNode* phead)
{
 assert(phead);

 int size = 0;
 ListNode* cur = phead->next;
 while (cur != phead)
 {
  size++;
  cur = cur->next;
 }
 return size;
}

链表销毁

void ListDestory(ListNode* phead)
{
 assert(phead);

 ListNode* cur = phead->next;
 while (cur != phead)
 {
  ListNode* next = cur->next;
  free(cur);
  cur = next;
 }

 free(phead);
 phead = NULL;
}

List.h

#pragma once
#define _CRT_SECURE_NO_WARNINGS 1

#include <stdlib.h>
#include <stdio.h>
#include <assert.h>

typedef int LTDataType;
typedef struct ListNode
{
 struct ListNode* next;
 struct ListNode* prev;
 LTDataType data;
}ListNode;

//打印
void ListPrint(ListNode* phead);

//申请空间
ListNode* BuyListNode(LTDataType x);

//初始化
ListNode* ListInit();

//尾插
void ListPushBack(ListNode* phead, LTDataType x);

//头插
void ListPushFront(ListNode* phead, LTDataType x);

//尾删
void ListPopBack(ListNode* phead);

//头删
void ListPopFront(ListNode* phead);

//查找
ListNode* ListFind(ListNode* phead, LTDataType x);

//插入
void ListInsert(ListNode* pos, LTDataType x);

//删除
void ListErase(ListNode* pos);

//空返回1，非空返回0
int ListEmpty(ListNode* phead);

//元素个数
int ListSize(ListNode* phead);

//链表销毁
void ListDestory(ListNode* phead);

List.c

#include "List.h"

ListNode* BuyListNode(LTDataType x)
{
 ListNode* node = (ListNode*)malloc(sizeof(ListNode));
 node->next = NULL;
 node->prev = NULL;
 node->data = x;
 return node;
}

ListNode* ListInit()
{
 ListNode* phead = BuyListNode(0);
 phead->next = phead;
 phead->prev = phead;

 return phead;
}

//打印
void ListPrint(ListNode* phead)
{
 ListNode* cur = phead->next;
 while (cur != phead)
 {
  printf("%d ", cur->data);
  cur = cur->next;
 }
 puts("\n------------------------------------------------\n");
}

void ListPushBack(ListNode* phead, LTDataType x)
{
 //assert(phead);
 //ListNode* tail = phead->prev;
 //ListNode* newnode = BuyListNode(x);

 //tail->next = newnode;
 //newnode->prev = tail;
 //newnode->next = phead;
 //phead->prev = newnode;

 ListInsert(phead, x);
}

//头插
void ListPushFront(ListNode* phead, LTDataType x)
{
 //assert(phead);
 //ListNode* first = phead->next;
 //ListNode* newnode = BuyListNode(x);
 phead newnode first
 //phead->next = newnode;
 //newnode->prev = phead;
 //newnode->next = first;
 //first->prev = newnode;

 ListInsert(phead->next, x);
}

//尾删
void ListPopBack(ListNode* phead)
{
 //assert(phead);
 //assert(phead->next != phead);

 //ListNode* tail = phead->prev;
 //ListNode* tailPrev = tail->prev;
 //free(tail);

 //tailPrev->next = phead;
 //phead->prev = tailPrev;

 ListErase(phead->prev);

}

//头删
void ListPopFront(ListNode* phead)
{
 //assert(phead);
 //assert(phead->next != phead);

 //ListNode* first = phead->next;
 //ListNode* second = first->next;

 //free(first);

 //phead->next = second;
 //second->prev = phead;

 ListErase(phead->next);
}

//查找
ListNode* ListFind(ListNode* phead, LTDataType x)
{
 assert(phead);

 ListNode* cur = phead->next;
 while (cur)
 {
  if (cur->data == x)
  {
   return cur;
  }
  cur = cur->next;
 }

 return NULL;
}

//插入
void ListInsert(ListNode* pos, LTDataType x)
{
 assert(pos);

 ListNode* prev = pos->prev;
 ListNode* newnode = BuyListNode(x);
 prev->next = newnode;
 newnode->prev = prev;
 newnode->next = pos;
 pos->prev = newnode;
}

//删除
void ListErase(ListNode* pos)
{
 assert(pos);

 ListNode* prev = pos->prev;
 ListNode* next = pos->next;

 prev->next = next;
 next->prev = prev;

 free(pos);
}

//空返回1，非空返回0
int ListEmpty(ListNode* phead)
{
 assert(phead);
 return phead->next == phead ? 1 : 0;
}

int ListSize(ListNode* phead)
{
 assert(phead);

 int size = 0;
 ListNode* cur = phead->next;
 while (cur != phead)
 {
  size++;
  cur = cur->next;
 }
 return size;
}

void ListDestory(ListNode* phead)
{
 assert(phead);

 ListNode* cur = phead->next;
 while (cur != phead)
 {
  ListNode* next = cur->next;
  free(cur);
  cur = next;
 }

 free(phead);
 phead = NULL;
}

test.c

#include "List.h"

void TestList1()
{
 ListNode* plist = ListInit();
 ListPushBack(plist, 1);
 ListPushBack(plist, 2);
 ListPushBack(plist, 3);
 ListPushBack(plist, 4);
 ListPrint(plist);

 ListPushFront(plist, 0);
 ListPushFront(plist, -1);
 ListPushFront(plist, -2);
 ListPrint(plist);

 ListPopFront(plist);
 ListPopFront(plist);
 ListPopFront(plist);
 ListPrint(plist);

 ListDestory(plist);
 plist = NULL;
}

int main()
{
 TestList1();
 return 0;
}

总结

链表优点：

1.按需申请内存，需要存一个数据，就申请一块内存。不存在空间浪费。
2.任意位置O(1)时间内插入删除数据

链表缺点：

1.不支持下标的随机访问
2.缓存命中率相对低。

顺序表优点

1.按下标去进行随机访问
2.cpu高速缓存命中率比较高

顺序表缺点

1.空间不够需要增容。（一定程序的性能消耗），可能存在一定的空间浪费
2.头部或者中间插入删除数据，需要挪动数据，效率比较低->O(N)

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