# class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None # @param proot TreeNode类 # @param k int整型 # @return int整型 # class Solution: def KthNode(self , pRoot: TreeNode, k: int): # step1.初始条件 if not pRoot or k<=0: return -1 queue = [pRoot] res = [] # step2.遍...