题库练习 Function Composition
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A12947 | Function Composition

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题目描述

We are definitely not going to bother you with another generic story when Alice finds about an array or when Alice and Bob play some stupid game. This time you'll get a simple, plain text.

First, let us define several things. We define function $F$ on the array $A$ such that $F(i, 1) = A[i]$ and $F(i, m) = A[F(i, m - 1)]$ for $m > 1$ . In other words, value $F(i, m)$ represents composition $A[...A[i]]$ applied $m$ times.

You are given an array of length $N$ with non-negative integers. You are expected to give an answer on $Q$ queries. Each query consists of two numbers – $m$ and $y$ . For each query determine how many $x$ exist such that $F(x,m) = y$ .

输入格式

The first line contains one integer $N$ $(1 \leq N \leq 2 \cdot 10^5)$ – the size of the array $A$ . The next line contains $N$ non-negative integers – the array $A$ itself $(1 \leq A_i \leq N)$ . The next line contains one integer $Q$ $(1 \leq Q \leq 10^5)$ – the number of queries. Each of the next $Q$ lines contain two integers $m$ and $y$ $(1 \leq m \leq 10^{18}, 1\leq y \leq N)$ .

输出格式

Output exactly $Q$ lines with a single integer in each that represent the solution. Output the solutions in the order the queries were asked in.

输入输出样例

输入 #1
10
2 3 1 5 6 4 2 10 7 7
5
10 1
5 7
10 6
1 1
10 8
输出 #1
3
0
1
1
0
C++ 编辑器
输入
输出