spoj#RTREE. Roger and tree
Roger and tree
Roger is a computer science student who likes connected undirected acyclic graphs, also known as trees. He especially likes solving problems about trees. Recently Roger found a piece of paper with a rooted tree with 'N' vertices drawn on it (numbered from 1 to 'N'). He also found 'Q' queries on the same piece of paper, where each query was an integer 'S' between 1 to 'N'. But the paper said nothing about the description of the queries. So he decided to find the longest path of each of the subtree 'S'.
Roger spent two sleepless nights trying to solve this problem efficiently. He is still trying and won't sleep until he knows the answer to each query. Write a program which answers all the queries correctly.
Input
The first line contains an integer 'N', then N-1 lines follow.
Each of the next 'N-1' line contains two integer 'U' and 'V' which means that vertex 'U' and 'V' are connected.
Next line contains an integer 'R' which denotes the root of the tree.
Next line contains another integer 'Q' which denotes the number of queries.
Each of the next 'Q' line contains an integer 'S' between (1 to N).
Output
For each query print the longest path of the subtree 'S' rooted at vertex 'R'.
Output exactly 'Q' lines, each line containing the output of the ith query.
Example
SAMPLE INPUT 3 1 2 1 3 1 2 1 2</p>SAMPLE OUTPUT 2 0
CONSTRAINTS
1 ≤ N ≤ 10^5
1 ≤ U,V ≤ N
1 ≤ R ≤ N
1 ≤ Q ≤ 10^5
1 ≤ S ≤ N
Like Trees? Try the problems: RTREE2, RTREE3 as well