Add valid-parentheses solution

Author: Jeehay28

valid-parentheses/Jeehay28.js

@@ -0,0 +1,35 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+
+// Time Complexity: O(n)
+// Space Complexity: O(n)
+var isValid = function (s) {
+  const obj = {
+    "(" : ")",
+    "{" : "}",
+    "[" : "]",
+  };
+
+  let stack = [];
+
+  for (any of s) {
+    // open bracket
+    if (obj[any]) {
+      stack.push(any);
+    } else {
+      // close bracket
+      if (stack.length === 0) {
+        return false;
+      } else if (obj[stack[stack.length - 1]] !== any) {
+        return false;
+      } else {
+        stack.pop();
+      }
+    }
+  }
+  return stack.length === 0 ? true : false;
+};
+
+