CF1712C.Sort Zero

An array is sorted if it has no inversions

A Young Boy

You are given an array of $n$ positive integers $a_1,a_2,\ldots,a_n$ .

In one operation you do the following:

1. Choose any integer $x$ .
2. 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.

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 $[0, 0, 0, 0]$ .