时间限制:C/C++/Rust/Pascal 1秒,其他语言2秒
空间限制:C/C++/Rust/Pascal 256 M,其他语言512 M
64bit IO Format: %lld
题目描述
A permutation of length
n is an array

, which contains every integer from 1 to n (inclusive) and each number appears exactly once. For example,
p=[3,1,4,6,2,5] is a permutation of length
6.
Let's call a permutation is a matching if and only if

and

for all valid i.
You are given an array

(

,

and n is even). Define the cost of a permutation is
)%20%2F%202)
.
Define two matchings
p,
q are combinable if and only if

for all
i from
1 to
n.
Please find two combinable matchings such that the sum of the cost of these two matchings is as small as possible. Output the sum.
输入描述:
The first line contains one integer t (
) --- the number of test cases.
Each test contains two lines. The first line contains one integer n (
and n is even), The second line contains n integers
(
).
The sum of n across the test cases doesn't exceed
.
输出描述:
For each test, output one line which contains only one integer representing the answer of this test.
示例1
输入
复制
2
4
0 8 0 0
6
3 1 4 1 5 9
说明
In the first test, one possible combinable matchings with the minimum sum of cost are [2,1,4,3] and [4,3,2,1]. The cost of the first matching is (|0-8| + |8-0| + |0-0| + |0-0|) / 2 = 8, the cost of the second matching is (|0-0| + |8-0| + |0-8| + |0-0|) / 2 = 8. So their sum is 8+8=16.