From 07e95e7a97f1bdf55386cbc6c05f6b9cfba88a04 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9E=81=E5=AE=A2=E5=AD=A6=E4=BC=9F?= <qxuwei@yeah.net>
Date: Mon, 16 Aug 2021 13:00:02 +0800
Subject: [PATCH 1/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20203.=E7=A7=BB=E9=99=A4?=
 =?UTF-8?q?=E9=93=BE=E8=A1=A8=E5=85=83=E7=B4=A0=20Swift=E7=89=88=E6=9C=AC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 problems/0203.移除链表元素.md | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/problems/0203.移除链表元素.md b/problems/0203.移除链表元素.md
index 9235d47e..f3724fc2 100644
--- a/problems/0203.移除链表元素.md
+++ b/problems/0203.移除链表元素.md
@@ -304,8 +304,7 @@ var removeElements = function(head, val) {
 };
 ```
 
-Swift:
-
+Swift：
 ```swift
 /**
  * Definition for singly-linked list.

From c7c52f7db6d92800a273057c3a5abc4cffcc8aef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9E=81=E5=AE=A2=E5=AD=A6=E4=BC=9F?= <qxuwei@yeah.net>
Date: Mon, 16 Aug 2021 20:28:38 +0800
Subject: [PATCH 2/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20707.=E8=AE=BE=E8=AE=A1?=
 =?UTF-8?q?=E9=93=BE=E8=A1=A8=20Swift=E7=89=88=E6=9C=AC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 problems/0707.设计链表.md | 64 +++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/problems/0707.设计链表.md b/problems/0707.设计链表.md
index 0aa038e8..33b02e56 100644
--- a/problems/0707.设计链表.md
+++ b/problems/0707.设计链表.md
@@ -948,6 +948,70 @@ class MyLinkedList {
 }
 ```
 
+Swift
+```Swift
+class MyLinkedList {
+    var size = 0
+    let head: ListNode
+    
+    /** Initialize your data structure here. */
+    init() {
+        head = ListNode(-1)
+    }
+    
+    /** Get the value of the index-th node in the linked list. If the index is invalid, return -1. */
+    func get(_ index: Int) -> Int {
+        if size > 0 && index < size {
+            var tempHead = head
+            for _ in 0..<index {
+                tempHead = tempHead.next!
+            }
+            let currentNode = tempHead.next!
+            return currentNode.val
+        } else {
+            return -1
+        }
+    }
+    
+    /** Add a node of value val before the first element of the linked list. After the insertion, the new node will be the first node of the linked list. */
+    func addAtHead(_ val: Int) {
+        addAtIndex(0, val)
+    }
+    
+    /** Append a node of value val to the last element of the linked list. */
+    func addAtTail(_ val: Int) {
+        addAtIndex(size, val)
+    }
+    
+    /** Add a node of value val before the index-th node in the linked list. If index equals to the length of linked list, the node will be appended to the end of linked list. If index is greater than the length, the node will not be inserted. */
+    func addAtIndex(_ index: Int, _ val: Int) {
+        if index > size {
+            return
+        }
+        let idx = (index >= 0 ? index : 0)
+        var tempHead = head
+        for _ in 0 ..< idx {
+            tempHead = tempHead.next!
+        }
+        let currentNode = tempHead.next
+        let newNode = ListNode(val, currentNode)
+        tempHead.next = newNode
+        size += 1
+    }
+    
+    /** Delete the index-th node in the linked list, if the index is valid. */
+    func deleteAtIndex(_ index: Int) {
+        if size > 0 && index < size {
+            var tempHead = head
+            for _ in 0 ..< index {
+                tempHead = tempHead.next!
+            }
+            tempHead.next = tempHead.next!.next
+            size -= 1
+        }
+    }
+}
+```
 
 
 -----------------------

From eaa0504acbdc195c0804ecaebd033528786e7939 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9E=81=E5=AE=A2=E5=AD=A6=E4=BC=9F?= <qxuwei@yeah.net>
Date: Wed, 18 Aug 2021 19:47:30 +0800
Subject: [PATCH 3/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20206.=E5=8F=8D=E8=BD=AC?=
 =?UTF-8?q?=E9=93=BE=E8=A1=A8=20Swift=E7=89=88=E6=9C=AC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 problems/0206.翻转链表.md | 37 +++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/problems/0206.翻转链表.md b/problems/0206.翻转链表.md
index 8bb359bd..0c850d52 100644
--- a/problems/0206.翻转链表.md
+++ b/problems/0206.翻转链表.md
@@ -334,6 +334,43 @@ fun reverseList(head: ListNode?): ListNode? {
 }
 ```
 
+Swift：
+```swift
+/// 双指针法 (迭代)
+/// - Parameter head: 头结点
+/// - Returns: 翻转后的链表头结点
+func reverseList(_ head: ListNode?) -> ListNode? {
+    if head == nil || head?.next == nil {
+        return head
+    }
+    var pre: ListNode? = nil
+    var cur: ListNode? = head
+    var temp: ListNode? = nil
+    while cur != nil {
+        temp = cur?.next
+        cur?.next = pre
+        pre = cur
+        cur = temp
+    }
+    return pre
+}
+
+/// 递归
+/// - Parameter head: 头结点
+/// - Returns: 翻转后的链表头结点
+func reverseList2(_ head: ListNode?) -> ListNode? {
+    return reverse(pre: nil, cur: head)
+}
+func reverse(pre: ListNode?, cur: ListNode?) -> ListNode? {
+    if cur == nil {
+        return pre
+    }
+    let temp: ListNode? = cur?.next
+    cur?.next = pre
+    return reverse(pre: cur, cur: temp)
+}
+```
+
 -----------------------
 * 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)