diff --git a/problems/0019.删除链表的倒数第N个节点.md b/problems/0019.删除链表的倒数第N个节点.md index 2a08cbc0..85e3eb48 100644 --- a/problems/0019.删除链表的倒数第N个节点.md +++ b/problems/0019.删除链表的倒数第N个节点.md @@ -204,6 +204,31 @@ fun removeNthFromEnd(head: ListNode?, n: Int): ListNode? { } ``` +Swift: +```swift +func removeNthFromEnd(_ head: ListNode?, _ n: Int) -> ListNode? { + if head == nil { + return nil + } + if n == 0 { + return head + } + let dummyHead = ListNode(-1, head) + var fast: ListNode? = dummyHead + var slow: ListNode? = dummyHead + // fast 前移 n + for _ in 0 ..< n { + fast = fast?.next + } + while fast?.next != nil { + fast = fast?.next + slow = slow?.next + } + slow?.next = slow?.next?.next + return dummyHead.next +} +``` + ----------------------- * 作者微信:[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw) * B站视频:[代码随想录](https://space.bilibili.com/525438321) diff --git a/problems/0024.两两交换链表中的节点.md b/problems/0024.两两交换链表中的节点.md index 0728e893..75a5f739 100644 --- a/problems/0024.两两交换链表中的节点.md +++ b/problems/0024.两两交换链表中的节点.md @@ -256,6 +256,27 @@ fun swapPairs(head: ListNode?): ListNode? { } ``` +Swift: +```swift +func swapPairs(_ head: ListNode?) -> ListNode? { + if head == nil || head?.next == nil { + return head + } + let dummyHead: ListNode = ListNode(-1, head) + var current: ListNode? = dummyHead + while current?.next != nil && current?.next?.next != nil { + let temp1 = current?.next + let temp2 = current?.next?.next?.next + + current?.next = current?.next?.next + current?.next?.next = temp1 + current?.next?.next?.next = temp2 + + current = current?.next?.next + } + return dummyHead.next +} +``` -----------------------