1993. Marked Ancestor

单点时限: 5.0 sec

内存限制: 256 MB

You are given a tree T that consists of N nodes. Each node is numbered from 1 to N, and node 1 is always the root node of T. Consider the following two operations on T:

  • M v: (Mark) Mark node v.
  • Q v: (Query) Print the index of the nearest marked ancestor of node v which is nearest to it. Initially, only the root node is marked.

Your job is to write a program that performs a sequence of these operations on a given tree and calculates the value that each Q operation will print. To avoid too large output file, your program is requested to print the sum of the outputs of all query operations. Note that the judges confirmed that it is possible to calculate every output of query operations in a given sequence.


The first line of the input contains two integers N and Q, which denotes the number of nodes in the tree T and the number of operations, respectively. These numbers meet the following conditions: 1 <= N <=100000 and 1 <= Q <= 100000.

The following N - 1 lines describe the configuration of the tree T. Each line contains a single integer pi(i = 2, . . . , N), which represents the index of the parent of i-th node.

The next Q lines contain operations in order. Each operation is formatted as “M v” or “Q v”, where v is the index of a node.


Print the sum of the outputs of all query operations in one line.


6 3
Q 5
M 3
Q 5

6 人解决,39 人已尝试。

18 份提交通过,共有 274 份提交。

8.8 EMB 奖励。

创建: 10 年,8 月前.

修改: 3 年,4 月前.

最后提交: 7 年,5 月前.

来源: Japan