feat: add swift implementation to lcof2 problem: No.085 (#3470)

Author: klever34

lcof2/剑指 Offer II 085. 生成匹配的括号/README.md

@@ -188,6 +188,31 @@ var generateParenthesis = function (n) {
 };
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func generateParenthesis(_ n: Int) -> [String] {
+        var ans = [String]()
+        dfs(0, 0, n, "", &ans)
+        return ans
+    }
+
+    private func dfs(_ left: Int, _ right: Int, _ n: Int, _ t: String, _ ans: inout [String]) {
+        if left == n && right == n {
+            ans.append(t)
+            return
+        }
+        if left < n {
+            dfs(left + 1, right, n, t + "(", &ans)
+        }
+        if right < left {
+            dfs(left, right + 1, n, t + ")", &ans)
+        }
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 085. 生成匹配的括号/Solution.swift

@@ -0,0 +1,20 @@
+class Solution {
+    func generateParenthesis(_ n: Int) -> [String] {
+        var ans = [String]()
+        dfs(0, 0, n, "", &ans)
+        return ans
+    }
+
+    private func dfs(_ left: Int, _ right: Int, _ n: Int, _ t: String, _ ans: inout [String]) {
+        if left == n && right == n {
+            ans.append(t)
+            return
+        }
+        if left < n {
+            dfs(left + 1, right, n, t + "(", &ans)
+        }
+        if right < left {
+            dfs(left, right + 1, n, t + ")", &ans)
+        }
+    }
+}