Hiho! is a serial contests we developed to help programmers improve their skills following some architecture. Tree, as a data struct, its most significant feature is that it can be divide in to several problem simply by its natural form, which it's similar to what we have told in "Dynamic Programming".

The tree problem "Latest Common Ancient", is solved by so many methods which were direct by diffrent kinds of thoughts and time complexity. Considering this situation, we decide to divide this problem into several "Hiho!", hope you will learn from it!