CSES - Company Queries I
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Gửi bài giải
Điểm:
1,00 (OI)
Giới hạn thời gian:
1.0s
Giới hạn bộ nhớ:
512M
Input:
stdin
Output:
stdout
Nguồn bài:
Dạng bài
Ngôn ngữ cho phép
C, C++, Java, Kotlin, Pascal, PyPy, Python, Scratch
A company has ~n~ employees, who form a tree hierarchy where each employee has a boss, except for the general director.
Your task is to process ~q~ queries of the form: who is employee ~x~'s boss ~k~ levels higher up in the hierarchy?
Input
- The first input line has two integers ~n~ and ~q~: the number of employees and queries. The employees are numbered ~1,2,\dots,n~, and employee ~1~ is the general director.
The next line has ~n-1~ integers ~e\_2,e\_3,\dots,e\_n~: for each employee ~2,3,\dots,n~ their boss.
Finally, there are ~q~ lines describing the queries. Each line has two integers ~x~ and ~k~: who is employee ~x~'s boss ~k~ levels higher up?
Output
- Print the answer for each query. If such a boss does not exist, print ~-1~.
Constraints
- ~1 \le n,q \le 2 \cdot 10^5~
- ~1 \le e\_i \le i-1~
- ~1 \le x \le n~
- ~1 \le k \le n~
Example Input
5 3
1 1 3 3
4 1
4 2
4 3
Example Output
3
1
-1
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