#P14764. [Opoi 2025] CCD 的不难题

[Opoi 2025] CCD 的不难题

Background

CCD once made a hard problem:

But that problem was too hard, and the statement was too long to fit, so we put a not-so-hard problem instead.

Problem Description

You are given a sequence of length nn and qq queries. For each query [l,r][l, r], find the largest number that appears exactly kk times in [l,r][l, r]. If there is no solution, output 00.

Forced online.

Input Format

The first line contains a positive integer nn.

The second line contains nn positive integers aia_i.

The third line contains a positive integer qq.

Then follow qq lines, each containing three positive integers l,r,k (lr)l, r, k\ (l \leq r).

This problem is forced online. For each query, all input numbers must be decrypted by xoring with lastanslastans. For the first query, lastans=0lastans = 0 by default.

Output Format

For each query, output the corresponding answer.

10
8 3 1 3 1 3 1 1 1 8 
10
1 5 1
13 1 13
8 8 1
0 8 5
2 5 2
2 7 7
6 7 1
2 10 2
9 10 10
6 10 3
8
0
1
0
3
0
3
8
0
1

Hint

Sample before encryption:

10
8 3 1 3 1 3 1 1 1 8 
10
1 5 1
5 9 5
8 8 1
1 9 4
2 5 2
1 4 4
6 7 1
1 9 1
1 2 2
6 10 3

This problem uses bundled testdata.

$$\def\arraystretch{1.2} \begin{array}{|c|c|c|} \hline \begin{array}{c} \tt{subtask}\\\hline 1\\\hline 2\\\hline \end{array} & \begin{array}{c} n,q\\\hline \le 10^4\\\hline \le 5\times10^4\\\hline \end{array} & \begin{array}{c} \tt{pts}\\\hline 20\\\hline 80\\\hline \end{array} \\\hline \end{array}$$

Constraints: For all data, 1k,ain5×1041 \leq k, a_i \leq n \leq 5\times10^4, and 1q5×1041 \leq q \leq 5\times10^4.

Translated by ChatGPT 5