题解 | #按之字形顺序打印二叉树#
按之字形顺序打印二叉树
https://www.nowcoder.com/practice/91b69814117f4e8097390d107d2efbe0
# 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 pRoot TreeNode类 # @return int整型二维数组 # # 每一层需要判断当前是奇数层还是偶数层,偶数层保存的结果要逆序 class Solution: def Print(self, pRoot: TreeNode) -> List[List[int]]: if not pRoot: return None flag = True ans = [] cur = [pRoot] nex = [] while cur: temp = [] for node in cur: temp.append(node.val) if node.left: nex.append(node.left) if node.right: nex.append(node.right) if flag: ans.append(temp) else: ans.append(temp[::-1]) flag = not flag cur = nex nex = [] return ans