// // 206-e1.swift // LeetCode // // Created by nuomi1 on 2019/1/8. // Updated by nuomi1 on 2021/5/24. // // Reverse Linked List // https://leetcode.com/explore/interview/card/top-interview-questions-easy/93/linked-list/560/ // https://leetcode.com/explore/learn/card/linked-list/219/classic-problems/1205/ // https://leetcode.com/problems/reverse-linked-list/ // 反转链表 // https://leetcode-cn.com/leetbook/read/top-interview-questions-easy/xnnhm6/ // https://leetcode-cn.com/leetbook/read/linked-list/f58sg/ // https://leetcode-cn.com/problems/reverse-linked-list/ // MARK: Iterative func reverseList(_ head: ListNode?) -> ListNode? { var newHead: ListNode? var currentNode = head while currentNode != nil { let tempNode = currentNode?.next currentNode?.next = newHead newHead = currentNode currentNode = tempNode } return newHead }