1008. 前序遍历构造二叉搜索树

src/com/gatsby/_1008ConstructBstFromPreorderTraversal.java

@@ -0,0 +1,45 @@
+package com.gatsby;
+
+import java.util.Objects;
+
+/**
+ * @ClassName: _1008ConstructBstFromPreorderTraversal
+ * @Description: 1008. 前序遍历构造二叉搜索树
+ * @author: Gatsby
+ * @date: 2022/7/29 11:21
+ */
+
+public class _1008ConstructBstFromPreorderTraversal {
+
+    private void insert(int val, TreeNode node) {
+        if (val < node.val) {
+            if (Objects.isNull(node.left)) {
+                node.left = new TreeNode(val);
+            } else {
+                insert(val, node.left);
+            }
+        } else {
+            if (Objects.isNull(node.right)) {
+                node.right = new TreeNode(val);
+            } else {
+                insert(val, node.right);
+            }
+        }
+    }
+
+    public TreeNode bstFromPreorder(int[] preorder) {
+        int len = preorder.length;
+        if (len == 0) {
+            return null;
+        }
+        TreeNode root = new TreeNode(preorder[0]);
+        for (int i = 1; i < len; ++i) {
+            insert(preorder[i], root);
+        }
+        return root;
+    }
+
+    // TODO 区间划分找分割点
+}
+
+