valid parentheses

Author: sonjh1217

valid-parentheses/sonjh1217.swift

@@ -0,0 +1,22 @@
+class Solution {
+    func isValid (_ s: String) -> Bool {
+        var brackets: [Character: Character] = ["(": ")", "[": "]", "{": "}"]
+        var closers = [Character]()
+        
+        for character in s {
+            if let closer = brackets[character] {
+                closers.append(closer)
+            } else if character == closers.last {
+                closers.removeLast()
+            } else {
+                return false
+            }
+        }
+        
+        return closers.isEmpty
+        
+        //시간 O(n) (string의 길이)
+        //공간 O(n)
+    }
+}
+