Freaks City

Given a base tree and a subset of its nodes, the virtual tree preserves the ancestral relationships among these nodes by including all pairwise LCAs and cnonecting them appropriately. This structure maintains relative node relationships while being linear in size relative to the input set. When nodes are sorted by their Euler tour order, the se ...

Problem Overview Given a tree with weighted nodes and multiple queries, each query asks for the sum of node weights along the path between two nodes x and y, where the weights fall within a specified range [l, r]. Solution Approach This problem can be efficiently solved using persistent segment trees (also known as chairman trees) combined with ...