链表逆置

代码：

 1 #include "stdafx.h"
 2 #include "assert.h"
 3 
 4 typedef int DataType;
 5 
 6 struct node 
 7 {
 8     DataType data;
 9     node * next;
10 };
11 
12 node * create_list(int a[], int n)
13 {
14     if (n <= 0)
15         return NULL;
16     node * first = new node;
17     first->data = a[0];
18     first->next = NULL;
19     node *cur = first;
20     for (int i=1;i)
21     {
22         node * next = new node;
23         next->data = a[i];
24         next->next = NULL;
25         cur->next = next;
26         cur = next;
27     }
28     return first;
29 }
30 
31 void printf_list(node *head)
32 {
33     while(head)
34     {
35         printf("%d ", head->data);
36         head = head->next;
37     }
38     printf("\n");
39 }
40 
41 node * reserve_list(node *head)
42 {
43     //assert(head != NULL);    
44     if(head == NULL)           //不管是笔试还是面试，这些细节都是考察要点！！！
45         return head;
46     node *pre = head, *post = head->next;
47     while(post)
48     {
49         node * temp = post->next;
50         post->next = pre;        
51         pre = post;
52         post = temp;
53     }
54     head->next = NULL;
55     return pre;
56 }
57 
58 node * recursion_reserve(node *head) //递归（也可以使用二级指针将newHead带出递归）
59 {
60     if (head == NULL)
61         return NULL;
62     
63     if (head->next == NULL)
64         return head;
65     
66     node * pre = head, * post = head->next;
67     
68     if(post->next == NULL)
69     {
70         post->next = pre;
71         pre->next = NULL; //去掉这句，当链表元素个数为2时，死循环。
72         return post;
73     }
74     else
75     {
76         node * newHead = recursion_reserve(post);    
77         post->next = pre;
78         pre->next = NULL;
79         return newHead;
80     }        
81 }
82 
83 int _tmain(int argc, _TCHAR* argv[])
84 {
85     int a[] = {1,2,3,4,5,6,7,8,9};
86 
87     node * head = create_list(a, sizeof(a)/sizeof(int));
88     printf_list(head);    
89 
90     node *reservedHead = reserve_list(head); //reserve_list(NULL) 
91     printf_list(reservedHead);    
92 
93     node *recursionHead = recursion_reserve(reservedHead);
94     printf_list(recursionHead);
95 
96     getchar();
97     return 0;
98 }

 

 

单链表的逆置-C++实现

单链表逆置

转载于:https://www.cnblogs.com/kira2will/p/4024387.html