Two Friends

5

4 votes
Graphs, Shortest Path Algorithms, Algorithms
Problem

Bod and Alice are going back to their home from their school through their routes. They want to meet in between but because Alice is running late so Bob will have to go out of his way to meet her. Help Bob find the minimum extra distance that he will have to cover to meet her.

You are given a tree that will represent the locality. 

The number of nodes in the tree is N.

You will be given N and in the following next N1 lines, you will be given two integers that represent the nodes that have an edge between them.

There are M queries. In each query help Bob find the minimum extra distance that he will have to cover to meet Alice.

You are given an integer M and in the following M lines you will be given 4 integers u1,v1,u2,v2

 u1 and v1 represent Bob's school and home whereas u2 and v2 represent Alice's school and home.

Input Format:

The first line of input data contains single integer T — the number of test cases in the test.

The first line contains a single integer N  

The following N1 lines two integers are given specifying the two nodes that have a edge between them.   

The next line contains a single integer M, the number of queries.  

The following M lines contain 4 integers u1,v1,u2,v2  specifying their respective college and their home nodes.   

Output Format:

For each query print the minimum extra distance that he needs to cover to meet her in new line.

Constraints:

1T1001N1051M1051u1,u2,v1,v2N

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

Sample explanation

Sample input queries - 

1 2 3 4

Output - 1

The minimum distance from any node in the path 1 to 2 to a node in the path 3 to 4 is 1,so the answer for this query is 1.

 

1 2 4 5

Output - 2

The minimum distance from any node in the path 1 to 2 to a node in the path 4 to 5 is 2,so the answer for this query is 2.

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