middle-of-the-linked-list.cs

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     public int val;
 *     public ListNode next;
 *     public ListNode(int val=0, ListNode next=null) {
 *         this.val = val;
 *         this.next = next;
 *     }
 * }
 */
public class Solution {
    public ListNode MiddleNode(ListNode head) {

        ListNode slow, fast;
        slow = fast = head;

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

        return slow;
    }
}