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

Author: a93a

kotlin/0538-convert-bst-to-greater-tree.kt

@@ -0,0 +1,19 @@
+class Solution {
+    fun convertBST(root: TreeNode?): TreeNode? {
+        var curSum = 0
+
+        fun dfs(node: TreeNode?) {
+            node?: return
+
+            dfs(node.right)
+            val temp = node.`val`
+            node.`val` += curSum
+
+            curSum += temp
+            dfs(node.left)
+        }
+
+        dfs(root)
+        return root
+    }
+}