Create 0538-convert-bst-to-greater-tree.js

Author: aadil42

javascript/0538-convert-bst-to-greater-tree.js

@@ -0,0 +1,28 @@
+/**
+ * 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)
+ * }
+ */
+/**
+ * Tree | reverse pre-order-traversal 
+ * Time O(n) | Space O(n)
+ * @param {TreeNode} root
+ * @return {TreeNode}
+ */
+var convertBST = function(root) {
+
+    const dfs = (node, max) =>  {
+        if(!node) return max;
+
+        const result = dfs(node.right, max);
+        node.val = result + node.val;
+        const result1 = dfs(node.left, node.val);
+        return result1;
+    }
+
+    dfs(root, 0);
+    return root;
+};