538

src/0538.convert-bst-to-greater-tree.538/solution.java

@@ -0,0 +1,31 @@
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode() {}
+ *     TreeNode(int val) { this.val = val; }
+ *     TreeNode(int val, TreeNode left, TreeNode right) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+class Solution {
+    int sum = 0;
+    public TreeNode convertBST(TreeNode root) {
+        if(root == null){
+            return null;
+        }
+        convertBST(root.right);
+
+        sum += root.val;;
+        root.val = sum;
+
+        convertBST(root.left);
+
+        return root;
+    }
+}