Mojtabas Trees and Arpas Queries <March HourStorm>

3.7

3 votes
Advanced Data Structures, Data Structures, Fenwick tree, Medium
Problem

Mojtaba has two trees, each of them has n vertices. Arpa has q queries, each in type v,u,x,y. Let s be the set of vertices in the path from v to u in the first tree and p be the set of vertices in the path from x to y in the second tree. Mojtaba has to calculate the size of sp for each query. Help him!

Input Format

The first line of input will contain two integers, n,q (1n,q3105).

The next n1 lines will contain edges of the first tree.

The next n1 lines will contain edges of the second tree.

The next q lines contain queries.

Output Format

For each query, let s be the set of vertices in the path from v to u in the first tree and p be the set of vertices in the path from x to y in the second tree, print the size of sp for each query.

Time Limit: 5
Memory Limit: 256
Source Limit:
Explanation

 

First Tree.second tree

The tree on the left is the first tree and the one in right is the second tree.

In the first query, s={4,1},p={5}, so the size of sp is 0.

In the third query, s={1,2,3,4,5},p={1,2,3}, so the answer is 3.

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