声明文件list.h
list.h
#ifndef _LIST_H_
#define _LIST_H_
#include<stdio.h>
#include<stdlib.h>
#include<Windows.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);//链表的初始化
void ListDestory(List* plist);
void ListPushBack(List* plist, LTDataType x);
void ListPopBack(List* plist);
void ListPushFront(List* plist, LTDataType x);
void ListPopFront(List* plist);
ListNode* ListFind(List* plist, LTDataType x);
void ListInsert(ListNode* pos, LTDataType x);
void ListErase(ListNode* pos);
void ListRemove(List* plist, LTDataType x);
void ListDistinct(List* plist);
void ListMerge(List * plist1,List * plist2);
void ListPrint(List* plist);
#endif
实现文件list.c
list.c
#include"List.h"
void ListInit(List* plist)//链表的初始化
{
plist->_head = (ListNode *)malloc(sizeof(ListNode));
plist->_head->_prev = plist->_head;
plist->_head->_next = plist->_head;
}
void ListDestory(List* plist)//链表的摧毁
{
while (plist->_head != plist->_head->_next)
{
ListPopFront(plist);
}
free(plist->_head);
plist->_head = NULL;
}
void ListPushBack(List* plist, LTDataType x)//后插
{
ListNode *cur = (ListNode *)malloc(sizeof(ListNode));
ListNode *tmp = plist->_head->_prev;
cur->_data = x;
tmp->_next = cur;
cur->_prev = tmp;
cur->_next = plist->_head;
plist->_head->_prev = cur;
}
void ListPopBack(List* plist)//后删
{
ListErase(plist->_head->_prev);
}
void ListPushFront(List* plist, LTDataType x)//头插
{
ListNode *cur = (ListNode *)malloc(sizeof(ListNode));
ListNode *tmp = plist->_head->_next;
cur->_data = x;
cur->_next = tmp;
tmp->_prev = cur;
plist->_head->_next = cur;
cur->_prev = plist->_head;
}
void ListPopFront(List* plist)//头删
{
ListErase(plist->_head->_next);
}
ListNode* ListFind(List* plist, LTDataType x)//找到data为x的结点
{
ListNode* cur;
for (cur = plist->_head->_next; cur != plist->_head; cur = cur->_next)
{
if (cur->_data == x)
{
return cur;
}
}
return NULL;
}
void ListInsertAfter(ListNode* pos, LTDataType x)//指定pos后插入x
{
ListNode *cur = (ListNode *)malloc(sizeof(ListNode));
cur->_data = x;
cur->_next = pos->_next;
pos->_next->_prev = cur;
pos->_next = cur;
cur->_prev = pos;
}
void ListInsertFront(ListNode* pos, LTDataType x)//指定pos前插入x
{
ListNode * cur = (ListNode *)malloc(sizeof(ListNode));
ListNode * tmp = pos->_prev;
cur->_data = x;
pos->_prev = cur;
cur->_next = pos;
tmp->_next = cur;
cur->_prev = tmp;
}
void ListErase(ListNode* pos)//删除pos位置的节点
{
pos->_prev->_next = pos->_next;
pos->_next->_prev = pos->_prev;
free(pos);
}
void ListRemove(List* plist, LTDataType x)//移除值为x的结点
{
ListNode *cur = ListFind(plist, x);
if (cur)
{
ListErase(cur);
}
}
void ListPrint(List* plist)//打印链表
{
ListNode *tmp = plist->_head;
printf("head");
for (tmp = plist->_head->_next; tmp != plist->_head; tmp = tmp->_next)
{
printf("->%d ", tmp->_data);
}
printf("->head");
}
测试文件main.c
main.c
#include"List.h"
int main()
{
List list1;
List list2;
ListInit(&list1);
ListInit(&list2);
ListPushFront(&list1, 7);
ListPushFront(&list1, 5);
ListPushFront(&list1, 3);
ListPushFront(&list1, 1);
ListPushFront(&list2, 9);
ListPushFront(&list2, 6);
ListPushFront(&list2, 4);
ListMerge(&list1, &list2);
//ListDistinct(&list);
//ListFind(&list, 6);
//ListInsertAfter(ListFind(&list, 6), 6);
//ListPopFront(&list);
//ListPopBack(&list);
ListPrint(&list1);
ListDestory(&list1);
system("pause");
return 0;
}
双链表的应用
一,删除链在一个排序的链表中,存在重复的节点,请删除表中重复的结点,重复的结点不保留,返回链表的头指针
//删除链表中重复的数
void ListDistinct(List* plist)
{
ListNode *cur = plist->_head->_next;//由于头的data为随机值,因此不需要遍历头,从头的下一位开始遍历一直遍历到头的前一位
while (cur != plist->_head)
{
if (cur->_data == cur->_next->_data)//当cur与cur->next的值相同时,就删掉后面的那个节点直到前后不相等是再进行cur前移
{
ListErase(cur->_next);
}
else
{
cur = cur->_next;
}
}
}
二,将两个有序链表合并为一个新的有序链表并返回。新链表是通过拼接给定的两个链表的所有节点组成的
//将两个有序链表合并为一个有序链表
void ListMerge(List * plist1, List * plist2)
{
ListNode *cur1 = plist1->_head->_next;
ListNode *cur2 = plist2->_head->_next;
ListNode * tmp1, *tmp2;
while(cur1 != plist1->_head && cur2 != plist2->_head)//跳出循环的出口当其中有一条链走到了头
{
if (cur1->_data > cur2->_data)//当cur1比cur2大时,将cur2所指的节点前插到cur1中
{
tmp1 = cur1->_prev; //由于CUR1会被修改,这里做一个备份******必须要做一个备份,不然在移动cur位置时会出问题
tmp2 = cur2->_next; //由于CUR2未来会被修改,这里做一个备份******必须要做一个备份,不然在移动cur位置时会出问题
cur1->_prev = cur2; // cur1左手拉起cur2
cur2->_next = cur1; // cur2右手拉起cur1,两手相连
tmp1->_next = cur2; // tmp1(cur1的prev)的右手拉起cur2
cur2->_prev = tmp1; // cur2的左手拉起tmp1,两手相连
cur2 = tmp2; // cur2找到它的下一个节点
}
else
{
cur1 = cur1->_next;
}
}//如果list2走到了头就表示其所有的节点都已经插入到list1中了,这时只需要释放头就行
if (cur1 == plist1->_head)//当list1走到头儿list2还未结束时,需要把list2剩余的节点接到list1后面。
{
cur2->_prev = cur1->_prev;
cur1->_prev->_next = cur2;
plist2->_head->_prev->_next = cur1;
cur1->_prev = plist2->_head->_prev;
}
free(plist2->_head);//释放掉list2的头
}