Merge pull request #1085 from Guang-Hou/patch-1

Update 0701.二叉搜索树中的插入操作.md

problems/0701.二叉搜索树中的插入操作.md

@@ -310,6 +310,26 @@ class Solution:
         return root
 ``` 
 
+**递归法** - 无返回值 - another easier way
+```python
+class Solution:
+    def insertIntoBST(self, root: Optional[TreeNode], val: int) -> Optional[TreeNode]:
+        newNode = TreeNode(val)
+        if not root: return newNode
+        
+        if not root.left and val < root.val:
+            root.left = newNode
+        if not root.right and val > root.val:
+            root.right = newNode
+        
+        if val < root.val:
+            self.insertIntoBST(root.left, val)
+        if val > root.val:
+            self.insertIntoBST(root.right, val)
+        
+        return root
+```
+
 **迭代法**  
 与无返回值的递归函数的思路大体一致 
 ```python