Merge pull request neetcode-gh#2204 from Ykhan799/main

Create: 0022-generate-parentheses.swift

Author: Ykhan799

swift/0022-generate-parentheses.swift

@@ -0,0 +1,22 @@
+// Time: O(2^n)
+// Space: O(n)
+class Solution {
+    func generateParenthesis(_ n: Int) -> [String] {
+        var result: [String] = []
+        generate(n, 0, 0, "", &result)
+        return result
+    }
+
+    func generate(_ n: Int, _ open: Int, _ close: Int, _ str: String, _ result: inout [String]) {
+        if open == n && close == n {
+            result.append(str)
+            return
+        }
+        if open < n {
+            generate(n, open + 1, close, str + "(", &result)
+        }
+        if open > close {
+            generate(n, open, close + 1, str + ")", &result)
+        }
+    }
+}