C语言单链表的创建，插入，删除，逆致

学了一天数据结构的链表，决定写点什么，但是这玩意真是太蛋疼了，尤其是实在解决头节点的操作上困扰了很长时间，最后发现是主函数中的头节点没更新，当时奔溃的心都有了。
在本文的代码中加了很多代码的注释，代表了不同的编辑方案，切都可以编译通过，仅供参考
若有不足请广大博友指正。

/************************************************************************* > File Name: link.c    > Author: heathcliff    > Mail: -----------------------------     > Created Time: 2016年03月29日 星期二 14时01分11秒 ************************************************************************/#include<stdio.h>#include<stdlib.h>struct Node{    int data;    struct Node *next;};struct Node *create() //创建链表{    struct Node *p,*q,*head; //ｑ是前驱指针    char interrupt[10];　//终端符    p = q = head = (struct Node *) malloc (sizeof(struct Node));    printf("please input data:");    scanf("%d",&p->data);//  printf("interrupt? yes($),no(any key)  :  ");//  scanf("%s",interrupt);// while(p->data != interrupt[0]){    while(p->data != 0){        q = p;        p = (struct Node *) malloc (sizeof(struct Node));        printf("please input data:");        scanf("%d",&p->data);//      printf("interrupt? yes($),no(any key)  :  ");//      scanf("%s",interrupt);        q->next = p; //连接链表    }    p->next = NULL;    return head;}void print(struct Node *head){    while(head != NULL){        printf("%4d",head->data);        head = head->next;    }    printf("\n");}struct Node *delete(struct Node *head){    struct Node *p,*q;//q是前驱指针    p = q = head;    int del,d;    printf("\nplease input the del:");    scanf("%d",&del);    q = p = head;    while(p){        d = del;        if( p->data != d){            q = p;            p = p->next;        }        else             break;        if(!p){            printf("can't find\n");        }    }    if(p == head){        head = head->next;    }    else{        q->next = p->next;    }    return head;    free(p);}struct Node *insert(struct Node *head){    struct Node *p,*ins;    int e,inst;    printf("\nplease input the address(after) you want to insert:");    scanf("%d",&inst);    printf("\nplease input the element you want to insert:");    scanf("%d",&e);    p = (struct Node *) malloc (sizeof(struct Node));    p->data = e;    while(ins->data != inst){        ins = ins->next;    }    if(ins->next == NULL){        printf("can't find\n");    }    else{        p->next = ins->next;        ins->next = p;    }    if(head == NULL){        head = p;        p->next = NULL;    }//  else{ //insert after head//      p->next = head->next;//      head->next = p;//  }//  else{//insert before head//      p->next = head;//      head = p;//  }    return head;}struct Node *reverse(struct Node *head){    struct Node *p,*r;    if(head->next != NULL){        p = head;        r = p->next;        p->next = NULL;//link tail == NULL        printf("p->data = %d\n",p->data);        while(r){            p = r;            r = r->next;            p->next = head;            head = p;        }    }    printf("\nreverse success\n");    printf("The result is as following\n");    return head;}int main(void){    struct Node *head;    head = create();    print(head);/*下面这个地方一定要写成head = delete(head);以刷新head,博主就是在这里打成了delete(head);结果无法删除头节点，找了很久的bug，找到之后。。。。。。。*/    head = delete(head);    print(head);    head = insert(head);    print(head);    head = reverse(head);    print(head);    return 0;}