Swift: 876. Middle of the Linked List

swift/0876-middle-of-the-linked-list.swift

@@ -0,0 +1,21 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ * public var val: Int
+ * public var next: ListNode?
+ * public init() { self.val = 0; self.next = nil; }
+ * public init(_ val: Int) { self.val = val; self.next = nil; }
+ * public init(_ val: Int, _ next: ListNode?) { self.val = val; self.next = next; }
+ * }
+ */
+class Solution {
+ func middleNode(_ head: ListNode?) -> ListNode? {
+ var current = head
+ var middle = head
+ while let next = current?.next {
+ current = next.next
+ middle = middle?.next
+ }
+ return middle
+ }
+}