Leetcode 328 Odd Even Linked List

最新推荐文章于 2020-11-11 15:08:21 发布

转载最新推荐文章于 2020-11-11 15:08:21 发布 · 48 阅读

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原文链接：http://www.cnblogs.com/lilixu/p/5360128.html

本文介绍了一种在不使用额外空间的情况下，通过原地操作将链表中的奇数节点与偶数节点进行分离的方法。具体实现通过迭代遍历链表，将奇数节点与偶数节点分别连接，并在遍历结束后将偶数链表的头部连接到奇数链表之后。

Given a singly linked list, group all odd nodes together followed by the even nodes. Please note here we are talking about the node number and not the value in the nodes.

You should try to do it in place. The program should run in O(1) space complexity and O(nodes) time complexity.

Example:
Given 1->2->3->4->5->NULL,
return 1->3->5->2->4->NULL.

class Solution(object):
    def oddEvenList(self, head):
        if not head or not head.next:
            return head 
        p = head
        q = head.next
        qh = q
        while p.next and q.next:
            p.next = q.next
            p = p.next
            q.next = p.next
            q = q.next
        p.next = qh
        return head