时间限制：C/C++/Rust/Pascal 3秒，其他语言6秒
空间限制：C/C++/Rust/Pascal 128 M，其他语言256 M
64bit IO Format: %lld
题目描述
We define a value of an interval is the second largest number of it's elements, and of course an interval has at least two elements.
Given an array A with n elements and a number k, can you find the value of the kth largest interval?
输入描述:
The first line contains an integer number T, the number of test cases.
For each test case :
The first line contains two integer numbers n,k(2 ≤ n ≤ 105,1 ≤ k ≤ n(n−1)/2), the number of test cases.
The second lines contains n integers Ai(1 ≤ Ai ≤ 109), the elements of array A.
输出描述:
For each test case print the value of the kth largest interval.
示例1
输入
复制
2
3 3
1 2 3
5 1
1 2 2 3 3
说明
For the sample input, there are three intervals.
Interval [1 2 3] has value 2.
Interval [2 3] has value 2.
Interval [1 2] has value 1.
So the 3rd largest interval is [1 2] whose value is 1.