Given a sequence of binary trees, you are to write a program that prints a level-order traversal of each tree.

给定一个二叉树序列，你要写一个程序将每棵树按层序访问并打印出来。

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Given a sequence of binary trees, you are to write a program that prints a level-order traversal of each tree.

给定一个二叉树序列，你要写一个程序将每棵树按层序访问并打印出来。

youdao