feat: add swift implementation to lcof2 problem: No.034 (#3039)

Author: klever34

lcof2/剑指 Offer II 034. 外星语言是否排序/README.md

@@ -199,6 +199,40 @@ function isAlienSorted(words: string[], order: string): boolean {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func isAlienSorted(_ words: [String], _ order: String) -> Bool {
+        var index = [Character: Int]()
+        
+        for (i, char) in order.enumerated() {
+            index[char] = i
+        }
+        
+        for i in 0..<words.count - 1 {
+            let w1 = Array(words[i])
+            let w2 = Array(words[i + 1])
+            let l1 = w1.count
+            let l2 = w2.count
+            
+            for j in 0..<max(l1, l2) {
+                let i1 = j >= l1 ? -1 : index[w1[j]]!
+                let i2 = j >= l2 ? -1 : index[w2[j]]!
+                
+                if i1 > i2 {
+                    return false
+                }
+                if i1 < i2 {
+                    break
+                }
+            }
+        }
+        return true
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 034. 外星语言是否排序/Solution.swift

@@ -0,0 +1,29 @@
+class Solution {
+    func isAlienSorted(_ words: [String], _ order: String) -> Bool {
+        var index = [Character: Int]()
+        
+        for (i, char) in order.enumerated() {
+            index[char] = i
+        }
+        
+        for i in 0..<words.count - 1 {
+            let w1 = Array(words[i])
+            let w2 = Array(words[i + 1])
+            let l1 = w1.count
+            let l2 = w2.count
+            
+            for j in 0..<max(l1, l2) {
+                let i1 = j >= l1 ? -1 : index[w1[j]]!
+                let i2 = j >= l2 ? -1 : index[w2[j]]!
+                
+                if i1 > i2 {
+                    return false
+                }
+                if i1 < i2 {
+                    break
+                }
+            }
+        }
+        return true
+    }
+}