Given a rooted tree, each node has a boolean (0 or 1) labeled on it. Initially, all the labels are 0.
We define this kind of operation: given a subtree, negate all its labels.
And we want to query the numbers of 1’s of a subtree.
Multiple test cases.
First line, two integer N and M, denoting the numbers of nodes and numbers of operations and queries.(1<=N<=100000, 1<=M<=10000)
Then a line with N-1 integers, denoting the parent of node 2..N. Root is node 1.
Then M lines, each line are in the format “o node” or “q node“, denoting we want to operate or query on the subtree with root of a certain node.
For each query, output an integer in a line.
Output a blank line after each test case.
Sample Input3 2 1 1 o 2 q 1
Problem’s Author: CUI, Tianyi
批量地 修改子树 可以被看做段修改(把树通过一个入点出点路径序列来表示)，这样即转化为了线段树的段修改和段查询。