Add 538_Convert_BST_to_Greater_Tree.java

Author: Sean Prashad

Tree Depth First Search/538_Convert_BST_to_Greater_Tree.java

@@ -0,0 +1,17 @@
+class Solution {
+    public TreeNode convertBST(TreeNode root) {
+        dfs(root, 0);
+        return root;
+    }
+
+    private int dfs(TreeNode root, int value) {
+        if (root == null) {
+            return value;
+        }
+
+        int right = dfs(root.right, value);
+        root.val += right;
+        int left = dfs(root.left, root.val);
+        return left;
+    }
+}