@ -0,0 +1,23 @@ package com.github.masx200.leetcode_test.construct_binary_search_tree_from_preorder_traversal

Author: masx200

construct-binary-search-tree-from-preorder-traversal/index.kt

@@ -0,0 +1,23 @@
+package  com.github.masx200.leetcode_test.construct_binary_search_tree_from_preorder_traversal
+
+
+import com.github.masx200.leetcode_test.insert_into_a_binary_search_tree.TreeNode
+
+class Solution {
+    fun bstFromPreorder(preorder: IntArray): TreeNode? {
+        var index = 0
+        val len = preorder.size
+
+        fun dfs(lowerBound: Int, upperBound: Int): TreeNode? {
+            if (index == len) return null
+            val cur = preorder[index]
+            if (cur < lowerBound || cur > upperBound) return null
+            index++
+            val root = TreeNode(cur)
+            root.left = dfs(lowerBound, cur)
+            root.right = dfs(cur, upperBound)
+            return root
+        }
+        return dfs(Integer.MIN_VALUE, Integer.MAX_VALUE)
+    }
+}

er-cha-shu-ran-se-UGC/index.kt

@@ -8,7 +8,7 @@ class Solution {
     }
 }
 
-fun dfs(root: TreeNode?, k: Int): IntArray {
+private fun dfs(root: TreeNode?, k: Int): IntArray {
     val ans = IntArray(k + 1)
 
     if (root == null) {

pom.xml

@@ -86,6 +86,7 @@
                         </goals>
                         <configuration>
                             <sourceDirs>
+                                <sourceDir>construct-binary-search-tree-from-preorder-traversal</sourceDir>
                                 <source>er-cha-shu-ran-se-UGC</source>
                                 <source>utils</source>
                                 <source>add-two-integers</source>