剑指Offer 33 二叉搜索树的后序遍历序列

二叉搜索树的后序遍历序列

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的结果。如果是则输出Yes,否则输出No。假设输入的数组的任意两个数字都互不相同。

# -*- coding:utf-8 -*-
class Solution:
    def compareTree(self,inOrder,sequence):
        n = len(sequence)
        if n == 0:
            return True
        if n == 1:
            return True if inOrder[0] == sequence[0] else False
        root1 = sequence[-1]
        for i in range(n):
            if inOrder[i] == root1:
                break
        in1 = inOrder[:i]
        last1 = sequence[:i]
        
        in2 = inOrder[i+1:]
        last2 = sequence[i:n-1]
        return self.compareTree(in1,last1) and self.compareTree(in2,last2)
            
        
    def VerifySquenceOfBST(self, sequence):
        n = len(sequence)
        if n == 0:
            return False
        inOrder = sorted(sequence)
        root1 = sequence[-1]
        for i in range(n):
            if inOrder[i] == root1:
                break
        in1 = inOrder[:i]
        last1 = sequence[:i]
        
        in2 = inOrder[i+1:]
        last2 = sequence[i:n-1]
        return self.compareTree(in1,last1) and self.compareTree(in2,last2)
        # write code here