1 """ 2 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. 3 4 You should try to do it in place. The program should run in O(1) space complexity and O(nodes) time complexity. 5 6 Example 1: 7 8 Input: 1->2->3->4->5->NULL 9 Output: 1->3->5->2->4->NULL 10 11 Example 2: 12 13 Input: 2->1->3->5->6->4->7->NULL 14 Output: 2->3->6->7->1->5->4->NULL 15 16 """ 17 18 class ListNode: 19 def __init__(self, x): 20 self.val = x 21 self.next = None 22 class Solution(object): 23 def oddEvenList(self, head): 24 if head == None or head.next == None: #头结点限定条件 25 return head 26 27 odd = head 28 even = head.next 29 t = even #！！！记录偶数结点的起始位置 30 while even != None and even.next != None: 31 #！！！遍历结点，保持奇数偶数结点的相对位置 32 odd.next = even.next #连接奇数结点 33 odd = odd.next #调整位置 34 even.next = odd.next #连接偶数结点 35 even = even.next #调整位置 36 odd.next = t #整合链表 37 return head 38 39 """ 40 注意题意， 41 这里的奇数节点和偶数节点指的是节点编号的奇偶性， 42 而不是节点的值的奇偶性。 43 此类题只需要遍历一遍链表，需要两个指针来进行操作 44 如previous，current（leetcode83) 45 传送门https://blog.csdn.net/qq_17550379/article/details/80654239 46 """