Hello codeforces!

I recently got interested in the LCA problem and read a lot about it. I learned three methods for computing LCA queries:

• Using Sparse Table (But i didn't like that approach since the 2-d array gives me outofmemory exception when number of nodes is 10^5 )

• Transforming my rooted tree into an array and apply segment trees on it. This method works well for me but takes much too long to code.

• Using Union-Find data structure.

Which approach do you use and why? Thanks!