#876.Middle of the Linked List [LeetCode Grind 75 in Java]

class Solution {
    public ListNode middleNode(ListNode head) {

        ListNode slow = head;
        ListNode fast = head;

        while(fast != null && fast.next != null){
            slow = slow.next;
            fast = fast.next.next;
        }

        return slow;  
    }
}