LCA
Lower Common Ancestor Algorithm - Advanced Data
References
https://www.topcoder.com/thrive/articles/Range%20Minimum%20Query%20and%20Lowest%20Common%20Ancestor
https://cp-algorithms.com/graph/lca.html
https://en.wikipedia.org/wiki/Lowest_common_ancestor
https://www.geeksforgeeks.org/lowest-common-ancestor-binary-tree-set-1/