单向链表的随机删除节点(C语言)

最新推荐文章于 2024-09-09 21:22:46 发布

原创最新推荐文章于 2024-09-09 21:22:46 发布 · 481 阅读

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CC 4.0 BY-SA版权

文章标签：

#链表 #c语言 #数据结构

本文展示了如何使用C语言创建一个单向链表，初始化链表，随机删除节点以及删除所有节点。文章重点讨论了删除链表元素时的注意事项，特别是处理最后一个元素的删除问题。提供的代码包括链表初始化、打印链表、删除指定节点和删除所有节点的函数实现。

链表是c语言基本功，它考察了指针和结构体的熟练程度，最近写代码用到链表，发现单向链表在删除元素时如果没处理好的话容易出错，比如删除最后一个元素，经过一番调试，现整理代码如下。

//创建一个链表，随机删除2个node，再删除全部node

#include "stdafx.h"
#include "stdlib.h"

struct tag_list_node_t
{
int id;
struct tag_list_node_t *next;
};

struct package_t
{
int size; //list 个数
struct tag_list_node_t * mlist;
};
struct package_t package;

void list_init(struct package_t *pack,int len)
{
   int i;
   pack->size = len;
   struct tag_list_node_t *list=(struct tag_list_node_t *)malloc(sizeof(struct tag_list_node_t)) ;

   list->id = 0;

   list->next = NULL;
   pack->mlist = list;

   for(i=1;i<pack->size;i++)
   {
       struct tag_list_node_t *plist = (struct tag_list_node_t *)malloc(sizeof(struct tag_list_node_t)) ;

       if(plist == NULL)
       {
           printf("plist==null\n");
       }
       plist->id=i;

       plist->next = NULL;
       list->next = plist;

       list = list->next ;

   }
   list->next=NULL;

}

void printlist(struct package_t * pack)
{
   struct tag_list_node_t *plist = pack->mlist;
   int n;
   while(plist!=NULL)
   {
       printf("id:%d ",plist->id);
       printf("\n");
       plist = plist->next;

}
}

int DeleteNode(struct tag_list_node_t *pnode){
   if(pnode==NULL)
   {
       printf("pnode==NULL\n");
       return -1;
   }
   struct tag_list_node_t *q = pnode->next;
   if(q==NULL)
   {
       return -2;
   }

   pnode->id = q->id;
   pnode->next = q->next;
   free(q);
   q = NULL;

return 0;

}

//删除指定node
void deleteonenode(struct package_t * pack,unsigned short id)
{
   struct tag_list_node_t *plist = pack->mlist;
   int res =0;
   while(plist!=NULL)
   {
       if(plist->id == id)
       {
           res = DeleteNode(plist);
           if(res == -2)
           {

               struct tag_list_node_t *pre = pack->mlist;
               if(pre->next==NULL)//只剩下一个尾节点
               {
                   free(pre);
                   pre=NULL;
                   pack->mlist = NULL;
                   return ;
               }else
               {
                   while(pre->next!=plist)//找到前一个节点，对于单向链表
                   {
                       pre = pre->next;
                   }
                   pre->next=NULL;

                   free(plist);
                   plist = NULL;
                   break;
               }

           }else if(res == -1)
           {
               break;
           }else if(res == 0)
           {
               break;
           }

       }
       plist = plist->next;
   }
}

int deleteAllNode(struct package_t *pack)
{
   //struct tag_list_node_t *plist = pack->mlist;
   int i;
   for(i=0;i<4;i++)
   {
       deleteonenode(pack,i);
   }

return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
int n;

   list_init(&package,4);
   printf("all node:\n");
   printlist(&package);

   printf("delete one node: 3---\n");
   deleteonenode(&package,3);
   printlist(&package);

   printf("delete one node: 0---\n");
   deleteonenode(&package,0);
   printlist(&package);

   printf("delete all node---\n");
   deleteAllNode(&package);
   printlist(&package);
   return 0;
}