LuoTianyi and the Show
Contest: Codeforces Round 872 (Div. 1)
Difficulty rating: 1400
Tags: greedy, implementation

There are $$$n$$$ people taking part in a show about VOCALOID. They will sit in the row of seats, numbered $$$1$$$ to $$$m$$$ from left to right.

The $$$n$$$ people come and sit in order. Each person occupies a seat in one of three ways:

1. Sit in the seat next to the left of the leftmost person who is already sitting, or if seat $$$1$$$ is taken, then leave the show. If there is no one currently sitting, sit in seat $$$m$$$.
2. Sit in the seat next to the right of the rightmost person who is already sitting, or if seat $$$m$$$ is taken, then leave the show. If there is no one currently sitting, sit in seat $$$1$$$.
3. Sit in the seat numbered $$$x_i$$$. If this seat is taken, then leave the show.

Now you want to know what is the maximum number of people that can take a seat, if you can let people into the show in any order?

Input format:
Each test consists of multiple test cases. The first line contains a single integer $$$t$$$ ($$$1 \le t \le 10^4$$$) — the number of test cases. The description of test cases follows.

The first line of each test case contains two integers $$$n$$$ and $$$m$$$ ($$$1 \le n, m \le 10^5$$$) — the number of people and the number of seats.

The second line of each test case contains $$$n$$$ integers $$$x_1, x_2, \ldots, x_n$$$ ($$$-2 \le x_i \le m$$$, $$$x_i \ne 0$$$), the $$$i$$$-th of which describes the way in which the $$$i$$$-th person occupies a seat:

1. If $$$x_i=-1$$$, then $$$i$$$-th person takes the seat in the first way.
2. If $$$x_i=-2$$$, then $$$i$$$-th person takes the seat in the second way.
3. If $$$x_i > 0$$$, then the $$$i$$$-th person takes a seat in the third way, i.e. he wants to sit in the seat with the number $$$x_i$$$ or leave the show if it is occupied..

It is guaranteed that sum of $$$n$$$ and the sum of $$$m$$$ over all test cases don't exceed $$$10^5$$$.

Output format:
For each test case output a single integer — the maximum number of people who can occupy a seat.

Constraints:
Time limit: 2.0 s
Memory limit: 256.0 MB

Note:
In the first test case, all the people want to occupy the $$$5$$$ seat, so only $$$1$$$ people can occupy the seat.

In the second test case, we can let people in order $$$1, 2, 3, 4$$$, then all but the last person can take a seat.

In the third test case, we can let people into the show in that order:

Let the third person in:

–––3–––

Let the fourth person in:

–––34––

Let the fifth person in:

–––345–

Let the first person in:

––1345–

Let the second person in:

–21345–

Thus, all $$$5$$$ people took seats.

In the fifth test case, we can let people into the show in this order:

Let the fourth person in:

––––4–

Let the third person in:

–––34–

Let the sixth person in, he'll leave the show because he takes the third seat the third way and has to sit in the $$$4$$$ seat, but it's already taken:

–––34–

Let the fifth person in:

––534–

Let the first person in:

–1534–

Let the second person in:

21534–

Thus, $$$5$$$ of people took seats.

In the seventh test case, we can let people into the show in this order:

Let the third person in:

3––––––

Let the fourth person in:

34–––––

Let the fifth person in:

345––––

Let the sixth person in:

3456–––

Let the first person in:

34561––

Let the second person in, he will leave the show because he occupies the first way, but the $$$1$$$ seat is taken:

34561––

Thus, $$$5$$$ people took seats.

Example input:
10
3 10
5 5 5
4 6
1 -2 -2 1
5 7
-1 -1 4 -2 -2
6 7
5 -2 -2 -2 -2 -2
6 6
-1 1 4 5 -1 4
6 8
-1 -1 -1 3 -1 -2
6 7
5 -1 -2 -2 -2 -2
3 1
-2 -2 1
2 5
5 -2
1 2
-1

Example output:
1
3
5
6
5
5
5
1
2
1

Editorial: