Solution Valid parentheses

Author: doitduri

valid-parentheses/doitduri.swift

@@ -0,0 +1,23 @@
+class Solution {
+    func isValid(_ s: String) -> Bool {
+        let pair: [Character: Character] = [
+            "(": ")",
+            "[": "]",
+            "{": "}"
+        ]
+        
+        var stack: [Character] = []
+        
+        for char in s {
+            if pair.keys.contains(char) {
+                stack.append(char)
+            } else {
+                if stack.isEmpty || pair[stack.removeLast()] != char {
+                    return false
+                }
+            }
+        }
+        
+        return stack.isEmpty
+    }
+}