feat: add another solution to lc problem: no.98

tchx626 · tchx626 · commit 84b819581f4b · 2021-07-20T02:07:36.000+08:00
diff --git a/solution/0000-0099/0098.Validate Binary Search Tree/README.md b/solution/0000-0099/0098.Validate Binary Search Tree/README.md
@@ -106,6 +106,35 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * 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) {
+    let isValidBSTRec = function (root, min, max) {
+        if (!root) {
+            return true;
+        }
+        if (root.val <= min || root.val >= max) {
+            return false;
+        }
+        return isValidBSTRec(root.left, min, root.val) && isValidBSTRec(root.right, root.val, max);
+    }
+    return isValidBSTRec(root, -Infinity, Infinity);
+};
+```
+
 ### **...**
 
 ```
diff --git a/solution/0000-0099/0098.Validate Binary Search Tree/README_EN.md b/solution/0000-0099/0098.Validate Binary Search Tree/README_EN.md
@@ -98,6 +98,35 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * 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) {
+    let isValidBSTRec = function (root, min, max) {
+        if (!root) {
+            return true;
+        }
+        if (root.val <= min || root.val >= max) {
+            return false;
+        }
+        return isValidBSTRec(root.left, min, root.val) && isValidBSTRec(root.right, root.val, max);
+    }
+    return isValidBSTRec(root, -Infinity, Infinity);
+};
+```
+
 ### **...**
 
 ```
diff --git a/solution/0000-0099/0098.Validate Binary Search Tree/Solution.js b/solution/0000-0099/0098.Validate Binary Search Tree/Solution.js
@@ -26,3 +26,29 @@ var inOrderTraverse = function (node, arr) {
     inOrderTraverse(node.right, arr);
   }
 };
+
+//Solution 2
+/**
+ * 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) {
+    let isValidBSTRec = function (root, min, max) {
+        if (!root) {
+            return true;
+        }
+        if (root.val <= min || root.val >= max) {
+            return false;
+        }
+        return isValidBSTRec(root.left, min, root.val) && isValidBSTRec(root.right, root.val, max);
+    }
+    return isValidBSTRec(root, -Infinity, Infinity);
+};
