题解 | #实现二叉树先序,中序和后序遍历#
实现二叉树先序,中序和后序遍历
https://www.nowcoder.com/practice/a9fec6c46a684ad5a3abd4e365a9d362
# 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 the root of binary tree # @return int整型二维数组 # class Solution: def threeOrders(self , root: TreeNode) -> List[List[int]]: # write code here if not root: return [[],[],[]] elif root.left==root.right==None: return [[root.val],[root.val],[root.val]] first=[root.val]+self.threeOrders(root.left)[0]+self.threeOrders(root.right)[0] mid=self.threeOrders(root.left)[1]+[root.val]+self.threeOrders(root.right)[1] last=self.threeOrders(root.left)[2]+self.threeOrders(root.right)[2]+[root.val] return [first,mid,last]