Can anyone explain how we are taking the subtree in this problem??Link
I am solving the problem QTREE2 on Spoj.[](http://www.spoj.com/problems/QTREE2/) I am learning LCA and I have calculated LCA using euler tour.But I am unable to find the answer to the second type of query which asks about Kth node in a path from node a to node b in a tree.How do we solve it ??