update

Author: jasoncao11

97. 二叉搜索树的后序遍历序列.md

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+***输入一个整数数组，判断该数组是不是某二叉搜索树的后序遍历结果。如果是则返回 true，否则返回 false。假设输入的数组的任意两个数字都互不相同。***
+
+![algo36](./images/algo36.jpg)
+
+```
+class Solution:
+    def verifyPostorder(self, postorder: List[int]) -> bool:
+        n = len(postorder)
+        if n<=1:
+            return True
+        root = postorder[-1]
+        for i in range(n):
+            if postorder[i] > root:
+                break
+        #找到左右子树对应区间
+        left,right = postorder[:i],postorder[i:-1]
+        for k in right:
+            if k < root: 
+                return False
+        return self.verifyPostorder(left) and self.verifyPostorder(right)
+```