Update 0108.将有序数组转换为二叉搜索树.md 添加迭代法python3代码

problems/0108.将有序数组转换为二叉搜索树.md

@@ -352,6 +352,38 @@ class Solution:
         return mid_root
 ```
 
+**迭代**（左闭右开）
+```python
+class Solution:
+    def sortedArrayToBST(self, nums: List[int]) -> Optional[TreeNode]:
+        if len(nums) == 0: return None
+        root = TreeNode()  # 初始化
+        nodeSt = [root]
+        leftSt = [0]
+        rightSt = [len(nums)]
+
+        while nodeSt:
+            node = nodeSt.pop()  # 处理根节点
+            left = leftSt.pop()
+            right = rightSt.pop()
+            mid = left + (right - left) // 2
+            node.val = nums[mid]
+
+            if left < mid:  # 处理左区间
+                node.left = TreeNode()
+                nodeSt.append(node.left)
+                leftSt.append(left)
+                rightSt.append(mid)
+            
+            if right > mid + 1:  # 处理右区间
+                node.right = TreeNode()
+                nodeSt.append(node.right)
+                leftSt.append(mid + 1)
+                rightSt.append(right)
+        
+        return root
+```
+
 ## Go 
 
 递归（隐含回溯）