#3822. CF1000F One Occurrence-标准mo

CF1000F One Occurrence-标准mo

题目描述

You are given an array a a consisting of n n integers, and q q queries to it. i i -th query is denoted by two integers li l_i and ri r_i . For each query, you have to find any integer that occurs exactly once in the subarray of a a from index li l_i to index ri r_i (a subarray is a contiguous subsegment of an array). For example, if a=[1,1,2,3,2,4] a = [1, 1, 2, 3, 2, 4] , then for query (li=2,ri=6) (l_i = 2, r_i = 6) the subarray we are interested in is [1,2,3,2,4] [1, 2, 3, 2, 4] , and possible answers are 1 1 , 3 3 and 4 4 ; for query (li=1,ri=2) (l_i = 1, r_i = 2) the subarray we are interested in is [1,1] [1, 1] , and there is no such element that occurs exactly once.

Can you answer all of the queries?

输入格式

The first line contains one integer n n ( 1n5105 1 \le n \le 5 \cdot 10^5 ).

The second line contains n n integers a1,a2,,an a_1, a_2, \dots, a_n ( 1ai5105 1 \le a_i \le 5 \cdot 10^5 ).

The third line contains one integer q q ( 1q5105 1 \le q \le 5 \cdot 10^5 ).

Then q q lines follow, i i -th line containing two integers li l_i and ri r_i representing i i -th query ( 1lirin 1 \le l_i \le r_i \le n ).

输出格式

Answer the queries as follows:

If there is no integer such that it occurs in the subarray from index li l_i to index ri r_i exactly once, print 0 0 . Otherwise print any such integer.

输入输出样例 #1

输入 #1

6
1 1 2 3 2 4
2
2 6
1 2

输出 #1

4
0