剑指offer-二叉搜索树的后序遍历序列-python

# -*- coding:utf-8 -*-
class Solution:
    def VerifySquenceOfBST(self, sequence):
        if not sequence:
            return False
        lens = len(sequence)
        root = sequence[-1]
        #左子树
        for i in range(lens):
            if sequence[i]>root:
                break
        for j in range(i,lens):
            if sequence[j]<root:
                return False
        left=True        
        if i>0:
            left = self.VerifySquenceOfBST(sequence[:i])
        right=True
        if i <lens-1:
            right = self.VerifySquenceOfBST(sequence[i:-1])
        return left and right