题解 | #判断是不是二叉搜索树#
判断是不是二叉搜索树
https://www.nowcoder.com/practice/a69242b39baf45dea217815c7dedb52b
# class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None # # 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 # # # @param root TreeNode类 # @return bool布尔型 # class Solution: def isValidBST(self, root: TreeNode) -> bool: traversed = [] def inordercheck(node): if node.left: inordercheck(node.left) traversed.append(node.val) if node.right: inordercheck(node.right) inordercheck(root) for i in range(len(traversed)): if i > 0 and traversed[i] < traversed[i-1]: return False return True