feat: add swift code to lcci problems: No.01.02,02.05 (doocs#2557)

Author: klever34

lcci/01.02.Check Permutation/README.md

@@ -170,6 +170,33 @@ var CheckPermutation = function (s1, s2) {
 };
 ```
 
+```swift
+class Solution {
+    func CheckPermutation(_ s1: String, _ s2: String) -> Bool {
+        if s1.count != s2.count {
+            return false
+        }
+
+        var cnt = Array(repeating: 0, count: 26)
+
+        for char in s1 {
+            let index = Int(char.asciiValue! - Character("a").asciiValue!)
+            cnt[index] += 1
+        }
+
+        for char in s2 {
+            let index = Int(char.asciiValue! - Character("a").asciiValue!)
+            cnt[index] -= 1
+            if cnt[index] < 0 {
+                return false
+            }
+        }
+
+        return true
+    }
+}
+```
+
 <!-- tabs:end -->
 
 ### 方法二：排序

lcci/01.02.Check Permutation/README_EN.md

@@ -242,6 +242,33 @@ impl Solution {
 }
 ```
 
+```swift
+class Solution {
+    func CheckPermutation(_ s1: String, _ s2: String) -> Bool {
+        if s1.count != s2.count {
+            return false
+        }
+
+        var cnt = Array(repeating: 0, count: 26)
+
+        for char in s1 {
+            let index = Int(char.asciiValue! - Character("a").asciiValue!)
+            cnt[index] += 1
+        }
+
+        for char in s2 {
+            let index = Int(char.asciiValue! - Character("a").asciiValue!)
+            cnt[index] -= 1
+            if cnt[index] < 0 {
+                return false
+            }
+        }
+
+        return true
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->

lcci/01.02.Check Permutation/Solution.swift

@@ -0,0 +1,24 @@
+class Solution {
+    func CheckPermutation(_ s1: String, _ s2: String) -> Bool {
+        if s1.count != s2.count {
+            return false
+        }
+        
+        var cnt = Array(repeating: 0, count: 26)
+        
+        for char in s1 {
+            let index = Int(char.asciiValue! - Character("a").asciiValue!)
+            cnt[index] += 1
+        }
+        
+        for char in s2 {
+            let index = Int(char.asciiValue! - Character("a").asciiValue!)
+            cnt[index] -= 1
+            if cnt[index] < 0 {
+                return false
+            }
+        }
+        
+        return true
+    }
+}

lcci/02.05.Sum Lists/README.md

@@ -258,6 +258,40 @@ var addTwoNumbers = function (l1, l2) {
 };
 ```
 
+```swift
+/**
+* Definition for singly-linked list.
+*    class ListNode {
+*        var val: Int
+*        var next: ListNode?
+*        init(_ val: Int) {
+*            self.val = val
+*            self.next = nil
+*        }
+*    }
+*/
+
+class Solution {
+    func addTwoNumbers(_ l1: ListNode?, _ l2: ListNode?) -> ListNode? {
+        var carry = 0
+        let dummy = ListNode(0)
+        var current: ListNode? = dummy
+        var l1 = l1, l2 = l2
+
+        while l1 != nil || l2 != nil || carry != 0 {
+            let sum = (l1?.val ?? 0) + (l2?.val ?? 0) + carry
+            carry = sum / 10
+            current?.next = ListNode(sum % 10)
+            current = current?.next
+            l1 = l1?.next
+            l2 = l2?.next
+        }
+
+        return dummy.next
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->

lcci/02.05.Sum Lists/README_EN.md

@@ -261,6 +261,40 @@ var addTwoNumbers = function (l1, l2) {
 };
 ```
 
+```swift
+/**
+* Definition for singly-linked list.
+*    class ListNode {
+*        var val: Int
+*        var next: ListNode?
+*        init(_ val: Int) {
+*            self.val = val
+*            self.next = nil
+*        }
+*    }
+*/
+
+class Solution {
+    func addTwoNumbers(_ l1: ListNode?, _ l2: ListNode?) -> ListNode? {
+        var carry = 0
+        let dummy = ListNode(0)
+        var current: ListNode? = dummy
+        var l1 = l1, l2 = l2
+
+        while l1 != nil || l2 != nil || carry != 0 {
+            let sum = (l1?.val ?? 0) + (l2?.val ?? 0) + carry
+            carry = sum / 10
+            current?.next = ListNode(sum % 10)
+            current = current?.next
+            l1 = l1?.next
+            l2 = l2?.next
+        }
+
+        return dummy.next
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->

lcci/02.05.Sum Lists/Solution.swift

@@ -0,0 +1,30 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public var val: Int
+ *     public var next: ListNode?
+ *     public init(_ val: Int) {
+ *         self.val = val
+ *         self.next = nil
+ *     }
+ * }
+ */
+class Solution {
+    func addTwoNumbers(_ l1: ListNode?, _ l2: ListNode?) -> ListNode? {
+        var carry = 0
+        let dummy = ListNode(0)
+        var current: ListNode? = dummy
+        var l1 = l1, l2 = l2
+
+        while l1 != nil || l2 != nil || carry != 0 {
+            let sum = (l1?.val ?? 0) + (l2?.val ?? 0) + carry
+            carry = sum / 10
+            current?.next = ListNode(sum % 10)
+            current = current?.next
+            l1 = l1?.next
+            l2 = l2?.next
+        }
+
+        return dummy.next
+    }
+}