ProblemGiven 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.SolutionSOL.1class Solution { public ListNode middleNode(ListNode head) { ListNode fast = head, slow = head; while (fast != null && fast.next != null) { fast = fast.next.next; slow = slow.next; } return slow; }}SOL.2class Solution { public ListNode middleNode(ListNode head) { ListNode fast = head, slow = head; int n = 1; while (fast.next != null) { fast = fast.next; n++; } int k = n/2; while (k != 0) { slow = slow.next; k–; } return slow; }}