CF825G.Tree Queries
普及/提高-
通过率:0%
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题目描述
You are given a tree consisting of n vertices (numbered from 1 to n ). Initially all vertices are white. You have to process q queries of two different types:
- 1 x — change the color of vertex x to black. It is guaranteed that the first query will be of this type.
- 2 x — for the vertex x , find the minimum index y such that the vertex with index y belongs to the simple path from x to some black vertex (a simple path never visits any vertex more than once).
For each query of type 2 print the answer to it.
Note that the queries are given in modified way.
输入格式
The first line contains two numbers n and q ( 3<=n,q<=106 ).
Then n−1 lines follow, each line containing two numbers xi and yi ( 1<=x_{i}<y_{i}<=n ) and representing the edge between vertices xi and yi .
It is guaranteed that these edges form a tree.
Then q lines follow. Each line contains two integers ti and zi , where ti is the type of i th query, and zi can be used to restore xi for this query in this way: you have to keep track of the answer to the last query of type 2 (let's call this answer last , and initially last=0 ); then xi=(zi+last)modn+1 .
It is guaranteed that the first query is of type 1 , and there is at least one query of type 2 .
输出格式
For each query of type 2 output the answer to it.
输入输出样例
输入#1
4 6 1 2 2 3 3 4 1 2 1 2 2 2 1 3 2 2 2 2
输出#1
3 2 1