面试题目-链表反转

题目：输入一个链表的头结点，反转该链表，并返回反转后链表的头结点。链表结点定义如下：

1     struct Node{
2         object data;
3         Node *prev;
4         Node *next;
5         Node(const object &d = object(), Node *p = NULL, Node *n = NULL)
6         : data(d), prev(p), next(n) {}
7     };

 

 1 Node* reverseNonrecurisve(Node* phead) {
 2     Node* preversed_head    = NULL;
 3     Node* pnode             = phead;
 4     Node* pprev             = NULL;
 5     while(pnode != NULL)
 6     {
 7         //get the next node and save it
 8         Node* pnext =   pnode->next;
 9         //if the next node is NULL, the current node is the new head
10         if(pnext == NULL){
11             preversed_head = pnode;
12         
13         //reverse the link between node
14         pnode->next = pprev;
15         pnode->prev = pnext;
16         
17         //move forward on the list
18         pprev       = pnode;
19         pnode       = pnext;
20     }
21     return preversed_head;
22 }

 

posted on 2014-07-03 22:57  醉清风JM  阅读(206)  评论(0)  编辑  收藏  举报

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