链表逆序

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 
 4 typedef struct NODE
 5 {
 6     int data;
 7     struct NODE *next;    
 8 }Node;
 9 
10 Node* reverse(Node *head)
11 {
12     Node *p1, *p2, *p3;
13 
14     if(head == NULL || head->next == NULL)
15     {
16         return head;
17     }
18     
19     p1 = head;
20     p2 = p1->next;
21 
22     
23     while(p2)
24     {
25         p3 = p2->next;
26         p2->next = p1;
27         p1 = p2;
28         p2 = p3;
29     }
30 
31     head->next = NULL;
32     head = p1;
33 
34     return head;
35 }
36 
37 Node* create()
38 {
39     Node *p, *head, *s;
40     int num;
41     int i, x;    
42 
43     printf("please input the node number:");
44 
45     scanf("%d", &num);
46     if(num <= 0)
47     {
48         printf("error! The input number is wrong!!!\n");
49         return NULL;
50     }
51 
52     head = (Node*)malloc(sizeof(Node));
53     p = head;
54 
55     for(i = 0; i < num; i++)
56     {
57         scanf("%d", &x);
58         s = (Node*)malloc(sizeof(Node));
59         s->data = x;
60         p->next = s;
61         p = s;
62         
63     }
64 
65     head = head->next;
66     p->next = NULL;
67 
68     return head;
69     
70 }
71 
72 void main()
73 {
74     Node *head, *p;
75     head = create();
76     p = reverse(head);
77 
78     while(p)
79     {
80         printf("%d ", p->data);
81         p = p ->next;
82     }
83 
84     printf("\n");
85     
86 }
87 
88