题号:NC236068
时间限制:C/C++/Rust/Pascal 3秒,其他语言6秒
空间限制:C/C++/Rust/Pascal 512 M,其他语言1024 M
64bit IO Format: %lld
题目描述
There is a cyclic buffer of size

with readers from the

-st position to the

-th position (both inclusive). Let

(

) be the integer at the

-th position of the buffer initially. What's more,

form a permutation of

.
We're going to visit all the integers from

to

(both inclusive) in increasing order. An integer can be visited only when it is residing in positions with readers (that is to say, when it is in the first

positions). In case that an integer cannot be visited, we can shift the whole buffer in either directions any number of times.
- If we shift the buffer to the left once, integers in the
-th position will be moved to the
-th position if
, and integer in the
-st position will be moved to the
-th position. - If we shift the buffer to the right once, integers in the
-th position will be moved to the
-th position if
, and integer in the
-th position will be moved to the
-st position.
What's the minimum number of times to shift the buffer so that we can visit all the integers in increasing order?
输入描述:
There are multiple test cases. The first line of the input contains an integer

indicating the number of test cases. For each test case:
The first line contains two integers

and

(

) indicating the size of the buffer and the number of readers.
The second line contains

integers

(

) where

indicates the integer in the

-th position of the buffer initially.
It's guaranteed that the given

integers form a permutation of

. It's also guaranteed that the sum of

of all test cases will not exceed

.
输出描述:
For each test case output one line containing one integer indicating the minimum number of times to shift the buffer so that all integers can be visited in increasing order.
备注:
For the first sample test case:
Shift to the right once so the buffer becomes

.

and

can now be visited in order as they are in the first

positions.Shift to the left twice so the buffer becomes

.

,

and

can now be visited in order as they are in the first

positions.