2019-08-23剑指 叉搜索树的后序遍历序列

27min
1.list.pop()返回的不是数组，而是数
2.or 写成了and 导致-1数组越界
3.root写成0导致反例并不能及时终止

最终还是通过某个样例进行错误排查

class Solution:
    def VerifySquenceOfBST(self, sequence:List):
        if not sequence:return False
        return self.dfs(sequence)

    def dfs(self,sequence):
        if not sequence or len(sequence)==1:return True # or写成了and
        root=sequence[-1]
        i=0
        while i<len(sequence)-1 and sequence[i]<=root:  # i的边界条件要加上
            i+=1
        c=i
        while i<len(sequence)-1:
            if sequence[i]<=root:return False # 妈的这里写成0了
            i+=1
        return self.dfs(sequence[:c]) and self.dfs(sequence[c:-1])