Difficulty: Easy

Problem statement:

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:

The number of nodes in the given list will be between 1 and 100.

Another painfully easy problem. I’m surprised they didn’t start with these sooner.

My solution is extremely obvious. Time complexity is O(n) and space complexity is O(n).