Given a non-empty, singly linked list with head node head, return a middle node of linked list.
If there are two middle nodes, return the second middle node.
Example 1:
Input: [1,2,3,4,5]
Output: Node 3 from this list (Serialization: [3,4,5])
The returned node has value 3. (The judge‘s serialization of this node is [3,4,5]).
Note that we returned a ListNode object ans, such that:
ans.val = 3, ans.next.val = 4, ans.next.next.val = 5, and ans.next.next.next = NULL.
Example 2:
Input: [1,2,3,4,5,6]
Output: Node 4 from this list (Serialization: [4,5,6])
Since the list has two middle nodes with values 3 and 4, we return the second one.
Note:
1 and 100.
在判断回文链表的时候，分析过如何拿到中间结点了
https://www.cnblogs.com/chucklu/p/10428868.html
直接把结论拿过来用,通过双指针，快指针每次移动2个结点，慢指针每次移动1个结点。
奇数的时候(slow所在的位置是中间位置)
偶数的时候(slow所在的位置，是下半段的第一个结点)
public ListNode MiddleNode(ListNode head) { var slow = head; var fast = head; // Get the middle of the list. // Move slow by 1 and fast by 2 // slow will have the middle mode while (fast?.next != null) { fast = fast.next.next; slow = slow.next; } return slow; }
876. Middle of the Linked List
原文：https://www.cnblogs.com/chucklu/p/10525915.html