QOJ.ac

QOJ

Limite de temps : 1 s Limite de mémoire : 512 MB Points totaux : 100 Hackable ✓

#17309. Tap Tap Dance

Statistiques

The direction the compass points to / The direction the compass points to Is where the heart desires / Is where the heart desires

Yuki has a sequence $a$ of length $n$.

Yuki defines a "Fish-Fish" operation as follows:

  • Choose two integers $l$ and $r$ such that $1 \le l \le r \le n$.
  • Let $x$ be the $\operatorname{mex}$ of the subsequence $a_l \sim a_r$. Delete all elements in $a_l \sim a_r$ that are greater than $x$, and update $n$ to the new length of the sequence $a$.

You need to find the minimum number of "Fish-Fish" operations required to make the sequence $a$ as short as possible.

In this problem, the $\operatorname{mex}$ of a sequence is the smallest non-negative integer that does not appear in the sequence. For example:

  • $\operatorname{mex}(\{1,2,3\})=0$
  • $\operatorname{mex}(\{0\})=1$
  • $\operatorname{mex}(\{1,0,2,4\})=3$

Specifically, when the sequence is empty, its $\operatorname{mex}$ is $0$.

Input

This problem contains multiple test cases.

The first line of input contains two integers $c$ and $t$, representing the subtask ID and the number of test cases, respectively. The sample satisfies $c=0$.

Each test case is then provided as follows:

  • The first line contains an integer $n$.
  • The second line contains $n$ integers $a_1, \dots, a_n$.

Output

For each test case, output a single integer representing the minimum number of "Fish-Fish" operations required to make the sequence $a$ as short as possible.

Examples

Input 1

0 5
4
2 0 2 6
5
1 0 3 3 1
5
1 1 8 3 1
6
1 0 3 1 0 2
7
4 0 9 8 1 3 8

Output 1

1
2
1
3
2

Note

For the first test case, choosing $l=1$ and $r=n$ for the "Fish-Fish" operation makes the sequence $a$ become $\{0\}$. It is easy to prove that $0$ cannot be deleted, so the length of the sequence $a$ reaches its minimum.

For the second test case, one can first choose $l=1$ and $r=1$ for the "Fish-Fish" operation, making the sequence $a$ become $\{0, 3, 3, 1\}$. Then, choose $l=2$ and $r=4$ for the "Fish-Fish" operation, making the sequence $a$ become $\{0\}$, reaching the minimum length.

Constraints

Let $\sum n$ denote the sum of $n$ over a single test case.

For all test cases:

  • $1 \le t \le 10^5$
  • $1 \le n \le 5 \cdot 10^5$, $\sum n \le 5\cdot 10^5$
  • $0 \le a_i \le 10^9$ for all $1 \le i \le n$

This problem uses bundled testing.

  • Subtask 1 (18 points): $n \le 10$, $\sum n \le 10$.
  • Subtask 2 (5 points): The sequence $a$ is guaranteed not to contain $0$.
  • Subtask 3 (21 points): The sequence $a$ is guaranteed to contain exactly one $0$.
  • Subtask 4 (24 points): $a_i=0$ for all positive odd integers $i \le n$.
  • Subtask 5 (32 points): No special constraints.

Discussions

About Discussions

The discussion section is only for posting: General Discussions (problem-solving strategies, alternative approaches), and Off-topic conversations.

This is NOT for reporting issues! If you want to report bugs or errors, please use the Issues section below.

Open Discussions 0
No discussions in this category.

Issues

About Issues

If you find any issues with the problem (statement, scoring, time/memory limits, test cases, etc.), you may submit an issue here. A problem moderator will review your issue.

Guidelines:

  1. This is not a place to publish discussions, editorials, or requests to debug your code. Issues are only visible to you and problem moderators.
  2. Do not submit duplicated issues.
  3. Issues must be filed in English or Chinese only.
Active Issues 0
No issues in this category.
Closed/Resolved Issues 0
No issues in this category.