889

Author: ProHiryu

Tree/889.md

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+## Construct Binary Tree from Preorder and Postorder Traversal
+
+#### Description
+
+[link](https://leetcode.com/problems/leaf-similar-trees/)
+
+---
+
+#### Solution
+
+- See Code
+
+---
+
+#### Code
+
+> Complexity  T : O(N)   M : O(n)
+
+```python
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+class Solution:
+    def constructFromPrePost(self, pre: List[int], post: List[int]) -> TreeNode:
+        def buid_tree(pre, post):
+            if not pre:
+                return None
+            node = TreeNode(pre[0])
+            if len(pre) < 2:
+                return node
+            index = post.index(pre[1])
+            node.left = buid_tree(pre[1:2+index], post[:index+1])
+            node.right = buid_tree(pre[2+index:], post[index+1:])
+            return node
+        return buid_tree(pre, post)
+```