236 Lowest common ancestor - C# various topics covered through 2019 practice

Here is the post I write and share.

I also copy and paste the content in the following:

It is my practice for busy season from March to May for two online code assessments and one more phone screen. One of ideas is to finish another 100 algorithm on Leetcode, and pace myself sometimes to work on one algorithm with various approaches. It is for potential phone screen, I may get invited any time. So I like to learn how to prepare more carefully through practice.

Here are various topic I cover in my practice, and I also like to share the discussion post for each idea. Some of ideas are just to study code on existing discussion post.

I also use the algorithm to interview people on interviewing.io. It is important for me to learn various solutions first in order to be a good interviewer, and also learn from interview experience through a lot of interviewees.

If you have advice for adding more topics on this algorithm as an interviewer, please leave in the comments. I will add them one by one.

Topics

child-parent map, parent node, BFS
Post order traversal

how to build a path from p or q to root
how to build a path from root to p

recursive function - Do not understand
Recursive solution Easy to understand
Recursive solution with backtracking

Naive solution with Timeout and Complicated function
Timeout challenge
Timeout challenge - using a string to store path
Fix naive solution timeout with complicated function
learn elegent solution using back tracking and space efficiency, avoid timeout