Woodstock Blog

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[Google] Diameter of a Binary Tree



The diameter of a tree (sometimes called the width) is the number of nodes on the longest path between two leaves in the tree.


This is a similar question to [LeetCode 124] Binary Tree Maximum Path Sum. However there’s a significant difference which might be overlooked while coding.

Look at this example:

       0  1

If we only want to find the max path, that would return result of 5, which is root-to-rightmost-leaf. However, the diameter should be 4, which is the distance between 2 leaf nodes.

A solution is available for reading here.

For [Google] Crazy Distance Between Strings, there is another special case: {“1”, “11”, “10”}. The program will not output correct result (1), because this is not really the diameter of a tree, but instead, a max path from a non-leaf to a leaf. I leave this part for you to finish.


Refer to [Google] Crazy Distance Between Strings for complete code.