solve problem

Author: delight010

valid-parentheses/delight010.swift

@@ -0,0 +1,19 @@
+class Solution {
+    func isValid(_ s: String) -> Bool {
+        let dictionary: [Character: Character] = [")":"(", "]":"[", "}":"{"]
+        var stack: [Character] = []
+        for char in s {
+            if let closeBucket = dictionary[char] {
+                if stack.isEmpty == false, stack.removeLast() == closeBucket {
+                    continue
+                } else {
+                    return false
+                }
+            }
+            stack.append(char)
+        }
+        
+        return stack.isEmpty
+    }
+}
+