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CF2049A.MEX Destruction
MEX Destruction
Evirir the dragon snuck into a wizard's castle and found a mysterious contraption, and their playful instincts caused them to play with (destroy) it...
Evirir the dragon found an array of non-negative integers.
In one operation, they can choose a non-empty subarray of and replace it with the integer . They want to use this operation any number of times to make only contain zeros. It can be proven that this is always possible under the problem constraints.
What is the minimum number of operations needed?
An array is a subarray of an array if can be obtained from by the deletion of several (possibly, zero or all) elements from the beginning and several (possibly, zero or all) elements from the end.
The minimum excluded (MEX) of a collection of integers is defined as the smallest non-negative integer which does not occur in the collection .
Input
Each test contains multiple test cases. The first line contains the number of test cases (). The description of the test cases follows.
The first line of each test case contains a single integer (), the length of .
The second line of each test case contains space-separated integers, ().
It is guaranteed that the sum of over all test cases does not exceed .
Output
For each test case, output a single integer on a line, the minimum number of operations needed to make contain only zeros.
Note
In the first test case, Evirir can choose the subarray and replace it with , changing from to (where the chosen subarray is underlined). Therefore, the answer is .
In the second test case, already contains only s, so no operation is needed.
In the third test case, Evirir can change as follows: $[1, \underline{0, 1, 0, 1}] \to [\underline{1, 2}] \to [0]$. Here, and .
In the fourth test case, Evirir can choose to be the entire array , changing from to .
Samples
10
4
0 1 2 3
6
0 0 0 0 0 0
5
1 0 1 0 1
5
3 1 4 1 5
4
3 2 1 0
7
9 100 0 89 12 2 3
4
0 3 9 0
7
0 7 0 2 0 7 0
1
0
2
0 1
1
0
2
1
1
2
1
2
0
1
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