Day67

swolecoder · swolecoder · commit f3a46a3f21ac · 2020-12-16T09:16:10.000-05:00
diff --git a/Day67/index.js b/Day67/index.js
@@ -0,0 +1,29 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {boolean}
+ */
+var isValidBST = function (root) {
+
+
+    function helper(node, min, max) {
+        if (!node) return true;
+
+        if (node.val <= min || node.val >= max) return false;
+
+        let left = helper(node.left, min, node.val);
+        let right = helper(node.right, node.val, max)
+
+        return left && right
+
+    }
+
+    return helper(root, -Infinity, Infinity)
+};
diff --git a/README.md b/README.md
@@ -147,4 +147,8 @@ If you are loving solving problems in leetcode, please contact me to enjoy it to
 
 |Day 64| [131. Palindrome Partitioning](https://leetcode.com/problems/squares-of-a-sorted-array/) | [javascript]()|[:memo:](https://leetcode.com/problems/squares-of-a-sorted-array/)|Easy|
 
-|Day 65| [1485. Clone Binary Tree With Random Pointer](https://leetcode.com/problems/clone-binary-tree-with-random-pointer/) | [javascript]()|[:memo:](https://leetcode.com/problems/clone-binary-tree-with-random-pointer/)|Medium|
+|Day 65| [1485. Clone Binary Tree With Random Pointer](https://leetcode.com/problems/clone-binary-tree-with-random-pointer/) | [javascript]()|[:memo:](https://leetcode.com/problems/clone-binary-tree-with-random-pointer/)|Medium|
+
+|Day 66| [1485. Clone Binary Tree With Random Pointer](https://leetcode.com/problems/clone-binary-tree-with-random-pointer/) | [javascript]()|[:memo:](https://leetcode.com/problems/clone-binary-tree-with-random-pointer/)|Medium|
+
+|Day 67| [98. Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/) | [javascript]()|[:memo:](https://leetcode.com/problems/validate-binary-search-tree/)|Medium|
