A15021 | $Triple$

时间限制1s

内存限制256MB

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题目描述

Given an array $a$ of $n$ elements, print any value that appears at least three times or print -1 if there is no such value.

The first line contains an integer $t$ ( $1 \leq t \leq 10^4$ ) — the number of test cases. The first line of each test case contains an integer $n$ ( $1 \leq n \leq 2\cdot10^5$ ) — the length of the array. The second line of each test case contains $n$ integers $a_1, a_2, \dots, a_n$ ( $1 \leq a_i \leq n$ ) — the elements of the array. It is guaranteed that the sum of $n$ over all test cases does not exceed $2\cdot10^5$ .

For each test case, print any value that appears at least three times or print -1 if there is no such value.

输入 #1

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

输出 #1

C++ 编辑器

输入

输出