Sort Zero
Description
You are given an array of $n$ positive integers $a_1,a_2,\ldots,a_n$.
In one operation you do the following:
- Choose any integer $x$.
- For all $i$ such that $a_i = x$, do $a_i := 0$ (assign $0$ to $a_i$).
Find the minimum number of operations required to sort the array in non-decreasing order.
Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). Description of the test cases follows.
The first line of each test case contains a single integer $n$ ($1 \le n \le 10^5$).
The second line of each test case contains $n$ positive integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le n$).
It is guaranteed that the sum of $n$ over all test cases does not exceed $10^5$.
For each test case print one integer — the minimum number of operations required to sort the array in non-decreasing order.
Input
Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). Description of the test cases follows.
The first line of each test case contains a single integer $n$ ($1 \le n \le 10^5$).
The second line of each test case contains $n$ positive integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le n$).
It is guaranteed that the sum of $n$ over all test cases does not exceed $10^5$.
Output
For each test case print one integer — the minimum number of operations required to sort the array in non-decreasing order.
Samples
<div class="test-example-line test-example-line-even test-example-line-0">5</div><div class="test-example-line test-example-line-odd test-example-line-1">3</div><div class="test-example-line test-example-line-odd test-example-line-1">3 3 2</div><div class="test-example-line test-example-line-even test-example-line-2">4</div><div class="test-example-line test-example-line-even test-example-line-2">1 3 1 3</div><div class="test-example-line test-example-line-odd test-example-line-3">5</div><div class="test-example-line test-example-line-odd test-example-line-3">4 1 5 3 2</div><div class="test-example-line test-example-line-even test-example-line-4">4</div><div class="test-example-line test-example-line-even test-example-line-4">2 4 1 2</div><div class="test-example-line test-example-line-odd test-example-line-5">1</div><div class="test-example-line test-example-line-odd test-example-line-5">1</div><div class="test-example-line test-example-line-odd test-example-line-5"></div>
1
2
4
3
0
Note
In the first test case, you can choose $x = 3$ for the operation, the resulting array is $[0, 0, 2]$.
In the second test case, you can choose $x = 1$ for the first operation and $x = 3$ for the second operation, the resulting array is $[0, 0, 0, 0]$.