In the original method, we need to traversal every node and write the function named getDepth to get the depth of all sub trees in traverse method too.
But there is more suitable uniform iteration traversal algorithm, I use the map struct in the code segment where the node is Null.
If you have problem in understand, please feel free to communicate with me.

This leetcode problem can use level order traversal method, the difference between with the normal version is we should judge for None.
There is my python answer, please feel free to contact with me if you have any problem.

Update 0101.对称二叉树.md level order traversal

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添加 剑指Offer 58-II.左旋转字符串 Rust版本

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添加 剑指Offer 58-II.左旋转字符串 Rust版本

Update 0110.平衡二叉树.md python code via iterate

修正:(链表章节-> 移除链表元素)TS虚拟头节点版本代码错误

修改0349 - 用 Java stream 代替 for loop

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