单链表的创建、插入、删除

看网上资料，然后写的关于单链表的创建、插入、删除等方面的代码练练手，代码存在一些bug,仅供参考。

#include <stdio.h>#include <stdlib.h>//1.定义链表数据结构struct node {    int num;    struct node *next;};//函数声明struct node *creat(struct node *head);void print(struct node *head);struct node *del(struct node *head,int num);struct node *insert(struct node *head,int num,int count);int n = 0;  //节点的个数int main(){    int num = 0,count = 0;    struct node *head;    head = NULL;        //2.创建一个空表    //创建    printf("************************创建**********************\n");    head = creat(head); //创建单链表    print(head);        //打印单链表    //删除    printf("************************删除**********************\n");    printf("输入要删除的数据:\n");    scanf("%d",&num);     printf("num is %d\n",num);    head = del(head,num);    print(head);     //插入    while(1)    {        printf("*************************插入*********************\n");        printf("请输入要插入的位置:1---%d:::::",n+1);        scanf("%d",&count);        printf("请输入要插入的数据:");        scanf("%d",&num);        head = insert(head,num,count);        print(head);     }    return 0;}//链表的创建struct node *creat(struct node *head){    struct node *p1,*p2;    //3.利用malloc函数向系统申请节点    p1 = p2 = (struct node *)malloc(sizeof(struct node)); //申请节点    printf("输入大于0的值，小于等于0则结束，值的存放地址为:p1_addr = %d\n",p1);    scanf("%d",&p1->num);    p1->next = NULL;    while(p1->num > 0)    {        if(head == NULL)            head = p1;        else            p2->next = p1;        p2 = p1;        p1 = (struct node *)malloc(sizeof(struct node));        p1->next = NULL;//置空        n++;        printf("输入大于0的值，小于等于0则结束，值的存放地址为:p%d_addr = %d\n",n,p1);        scanf("%d",&p1->num);    }    free(p1);     p1 = NULL;    p2->next = NULL;    printf("输入结束\n");    return head;}//链表的遍历打印void print(struct node *head){    struct node *tmp;    tmp = head;    printf("链表打印开始!!!\n");    printf("节点个数为:%d\n",n);    while(tmp != NULL)    {        printf("输入的值为:num = %d,地址为:addr = %d\n",tmp->num,tmp);        tmp = tmp->next;    }    printf("链表打印结束!!!\n");}//链表的删除struct node *del(struct node *head,int num){    struct node *p1,*p2;    if(head == NULL)    {        printf("链表为空链表!!!\n");        return head;    }    p1 = head;    //开始查找    while((num != p1->num) && (p1->next != NULL))    {        p2 = p1;         //把p1节点赋给p2        p1 = p1->next;   //p1后移一个节点    }    if(p1->num == num)  //找到此数字    {        if(p1 == head)  //若p1是首结点            head = p1->next;        else        {            p2->next = p1->next;  //把要删除的p1所指向的下一个            free(p1);        }        n--;  //节点数减1    }    else               //没有找到这个数字    {        printf("没有发现%d\n",num);    }    return head;}//链表的插入struct node *insert(struct node *head,int num,int count){    struct node *p0,*p1,*p2;    p1 = (struct node *)malloc(sizeof(struct node));    p1->num = num;    p1->next = NULL;    p0 = head;    p2 = p0->next;    //查找要插入的位置    if(count == n + 1)  //插入尾部    {        while(p0->next != NULL)  //找到链表最后面        {            p0 = p0->next;        }        p0->next = p1;    }    else if(count == 1) //插入头部    {        p1->next = head;        head = p1;    }    else    {        for(;count > 2;count--)        {            p0 = p0->next;            p2 = p0->next;        }        p1->next = p0->next;        p0->next = p1;    }    n++;    return head;}

运行结果这里就不贴图了，仅供参考，如果那里有错误，敬请指教。