feat: add swift implementation to lcof2 problem: No.065 (#3179)

Author: klever34

lcof2/剑指 Offer II 065. 最短的单词编码/README.md

@@ -218,6 +218,51 @@ func dfs(cur *trie, l int) int {
 }
 ```
 
+#### Swift
+
+```swift
+class Trie {
+    var children = [Trie?](repeating: nil, count: 26)
+}
+
+class Solution {
+    func minimumLengthEncoding(_ words: [String]) -> Int {
+        let root = Trie()
+        
+        for word in words {
+            var current = root
+            for char in word.reversed() {
+                let index = Int(char.asciiValue! - Character("a").asciiValue!)
+                if current.children[index] == nil {
+                    current.children[index] = Trie()
+                }
+                current = current.children[index]!
+            }
+        }
+        
+        return dfs(root, 1)
+    }
+    
+    private func dfs(_ current: Trie, _ length: Int) -> Int {
+        var isLeaf = true
+        var result = 0
+        
+        for child in current.children {
+            if let child = child {
+                isLeaf = false
+                result += dfs(child, length + 1)
+            }
+        }
+        
+        if isLeaf {
+            result += length
+        }
+        
+        return result
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 065. 最短的单词编码/Solution.swift

@@ -0,0 +1,40 @@
+class Trie {
+    var children = [Trie?](repeating: nil, count: 26)
+}
+
+class Solution {
+    func minimumLengthEncoding(_ words: [String]) -> Int {
+        let root = Trie()
+        
+        for word in words {
+            var current = root
+            for char in word.reversed() {
+                let index = Int(char.asciiValue! - Character("a").asciiValue!)
+                if current.children[index] == nil {
+                    current.children[index] = Trie()
+                }
+                current = current.children[index]!
+            }
+        }
+        
+        return dfs(root, 1)
+    }
+    
+    private func dfs(_ current: Trie, _ length: Int) -> Int {
+        var isLeaf = true
+        var result = 0
+        
+        for child in current.children {
+            if let child = child {
+                isLeaf = false
+                result += dfs(child, length + 1)
+            }
+        }
+        
+        if isLeaf {
+            result += length
+        }
+        
+        return result
+    }
+}