AC https://leetcode-cn.com/problems/inorder-successor-in-bst-ii/

Author: AaronLinRC

src/main/kotlin/leetcode/inorder-successor-in-bst-ii/Solution.kt

@@ -0,0 +1,25 @@
+package leetcode.`inorder-successor-in-bst-ii`
+
+import TreeNode
+
+class Solution {
+    fun inorderSuccessor(node: Node?): Node? {
+        node ?: return null
+        var explore: Node?
+        return if (node.right == null) {
+            explore = node
+            while (explore != null && explore == explore.parent?.right) explore = explore.parent
+            explore?.parent
+        } else {
+            explore = node.right
+            while (explore?.left != null) explore = explore.left
+            explore
+        }
+    }
+
+    class Node(var `val`: Int) {
+        var left: Node? = null
+        var right: Node? = null
+        var parent: Node? = null
+    }
+}