add: #222 Valid Parentheses

Author: sukyoungshin

valid-parentheses/sukyoungshin.ts

@@ -0,0 +1,24 @@
+const pairs = {
+  ")": "(",
+  "}": "{",
+  "]": "[",
+};
+
+function isValid(s: string): boolean {
+  const stack: string[] = [];
+  for (let i = 0; i < s.length; i++) {
+    const str = s[i];
+
+    if (str in pairs) {
+      if (pairs[str] !== stack[stack.length - 1]) {
+        return false;
+      } else {
+        stack.pop();
+      }
+    } else {
+      stack.push(str);
+    }
+  }
+
+  return stack.length === 0;
+};