leetcode刷题笔记(Golang)--328. Odd Even Linked List

328. Odd Even Linked List
     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 1:

Input: 1->2->3->4->5->NULL
Output: 1->3->5->2->4->NULL
Example 2:

Input: 2->1->3->5->6->4->7->NULL
Output: 2->3->6->7->1->5->4->NULL
Note:

The relative order inside both the even and odd groups should remain as it was in the input.
The first node is considered odd, the second node even and so on …

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func oddEvenList(head *ListNode) *ListNode {
	if head == nil || head.Next == nil {
		return head
	}
	dummy := &ListNode{Val: 0}
	even := &ListNode{Val: 0}
	dummy.Next = even
    curr := head
	for curr != nil && curr.Next != nil {
		even.Next = curr.Next
		even = even.Next
		curr.Next = curr.Next.Next
        if curr.Next== nil {
            break
        }
        curr = curr.Next
	}
	even.Next = nil
    curr.Next = dummy.Next.Next
	return head    
}

来源：CSDN

作者：圆滚滚coder

链接：https://blog.csdn.net/weixin_44555304/article/details/104700718