c链表结点的删除和添加

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 typedef char datetype;/*定义新的数据类型名*/
 4 typedef struct node
 5 {
 6     datetype date;
 7     struct node *next;
 8 }listnode;
 9 typedef listnode *linklist;
10 int delete(linklist h,int num)/*删除结点*/
11 {
12     linklist p=h;
13     listnode *q=NULL;
14     int i=num;
15     int n=1;
16     while(n<i)/*寻找删除位置*/
17     {
18         q=p;/*该结点和前后两个结点*/
19         p=p->next;
20         n++;
21     }
22     if(p==NULL)/*该结点不存在*/
23         printf("No Found Node!");
24     else
25     {
26         q->next=p->next;
27         free(p);
28     }
29 }
30 
31 void output(linklist head)/*链表遍历*/
32 {   
33     linklist p=head;
34     while(p!=NULL)
35     {
36         printf("%c",p->date);
37         p=p->next;
38     }
39 }
40 int rear_creat(linklist head,int index0,int m)/*插入新结点，链表头，结点位置，结点date*/
41 {
42     linklist k,g;
43     int i=index0,n;
44     k=head;
45     n=1;
46     while(n<i)/*寻找结点位置*/
47     {
48         n++;
49         k=k->next;
50     }
51     g=(listnode *)malloc(sizeof(listnode));
52     g->next=k->next;
53     g->date=m;
54     k->next=g;
55 }
56 int main()
57 {
58     char ch;
59     int index,index0;
60     char m;
61     linklist head=NULL;
62     listnode *p,*r;
63     ch=getchar();
64     while(ch!=‘\n‘)
65     {
66         p=(listnode *)malloc(sizeof(listnode));
67         p->date=ch;
68         if(head==NULL)
69             head=p;
70         else
71             r->next=p;
72         r=p;
73         ch=getchar();
74     }
75     output(head);
76     printf("\ndelete a node:\n");
77     scanf("%d",&index);
78     if(index==1)
79         head=head->next;
80     else
81         delete(head,index);
82     output(head);
83 
84     printf("\ncreat a node:\n");
85     scanf("%d%c",&index0,&m);
86     rear_creat(head,index0,m);
87     output(head);
88     return 0;
89 }