CF1223D.Sequence Sorting

You are given a sequence $a_1, a_2, \dots, a_n$, consisting of integers.

You can apply the following operation to this sequence: choose some integer $x$ and move all elements equal to $x$ either to the beginning, or to the end of $a$. Note that you have to move all these elements in one direction in one operation.

For example, if $a = [2, 1, 3, 1, 1, 3, 2]$, you can get the following sequences in one operation (for convenience, denote elements equal to $x$ as $x$-elements):

• $[1, 1, 1, 2, 3, 3, 2]$ if you move all $1$-elements to the beginning;
• $[2, 3, 3, 2, 1, 1, 1]$ if you move all $1$-elements to the end;
• $[2, 2, 1, 3, 1, 1, 3]$ if you move all $2$-elements to the beginning;
• $[1, 3, 1, 1, 3, 2, 2]$ if you move all $2$-elements to the end;
• $[3, 3, 2, 1, 1, 1, 2]$ if you move all $3$-elements to the beginning;
• $[2, 1, 1, 1, 2, 3, 3]$ if you move all $3$-elements to the end;

You have to determine the minimum number of such operations so that the sequence $a$ becomes sorted in non-descending order. Non-descending order means that for all $i$ from $2$ to $n$, the condition $a_{i-1} \le a_i$ is satisfied.

Note that you have to answer $q$ independent queries.

给你一个由整数组成的序列 $a_1, a_2, \dots, a_n$。

你可以对这个序列执行如下操作：选择某个整数 $x$，并将所有等于 $x$ 的元素全部移动到序列 $a$ 的开头或末尾。注意：在一次操作中，你必须将所有这些元素朝同一方向移动。

例如，若 $a = [2, 1, 3, 1, 1, 3, 2]$，则一次操作后可得到以下序列（为方便起见，将等于 $x$ 的元素记为 $x$-元素）：

• $[1, 1, 1, 2, 3, 3, 2]$：将所有 $1$-元素移至开头；
• $[2, 3, 3, 2, 1, 1, 1]$：将所有 $1$-元素移至末尾；
• $[2, 2, 1, 3, 1, 1, 3]$：将所有 $2$-元素移至开头；
• $[1, 3, 1, 1, 3, 2, 2]$：将所有 $2$-元素移至末尾；
• $[3, 3, 2, 1, 1, 1, 2]$：将所有 $3$-元素移至开头；
• $[2, 1, 1, 1, 2, 3, 3]$：将所有 $3$-元素移至末尾。

你需要确定使序列 $a$ 变为非降序排列所需的最少操作次数。非降序排列指对所有从 $2$ 到 $n$ 的 $i$，均满足 $a_{i-1} \le a_i$。

注意：你需要回答 $q$ 个相互独立的查询。

The first line contains one integer $q$ ($1 \le q \le 3 \cdot 10^5$) — the number of the queries. Each query is represented by two consecutive lines.

The first line of each query contains one integer $n$ ($1 \le n \le 3 \cdot 10^5$) — the number of elements.

The second line of each query contains $n$ integers $a_1, a_2, \dots , a_n$ ($1 \le a_i \le n$) — the elements.

It is guaranteed that the sum of all $n$ does not exceed $3 \cdot 10^5$.

第一行包含一个整数 $q$（$1 \le q \le 3 \cdot 10^5$），表示查询次数。每次查询由连续的两行表示。

每次查询的第一行包含一个整数 $n$（$1 \le n \le 3 \cdot 10^5$），表示元素个数。

每次查询的第二行包含 $n$ 个整数 $a_1, a_2, \dots , a_n$（$1 \le a_i \le n$），表示这些元素。

保证所有查询的 $n$ 值之和不超过 $3 \cdot 10^5$。

For each query print one integer — the minimum number of operation for sorting sequence $a$ in non-descending order.

对于每个查询，输出一个整数——将序列 $a$ 按非降序排序所需的最少操作次数。

In the first query, you can move all $1$-elements to the beginning (after that sequence turn into $[1, 1, 1, 3, 6, 6, 3]$) and then move all $6$-elements to the end.

In the second query, the sequence is sorted initially, so the answer is zero.

In the third query, you have to move all $2$-elements to the beginning.

在第一次查询中，你可以将所有 $1$-元素移动到开头（之后序列变为 $[1, 1, 1, 3, 6, 6, 3]$），然后将所有 $6$-元素移动到末尾。

在第二次查询中，序列初始时已排序，因此答案为零。

在第三次查询中，你必须将所有 $2$-元素移动到开头。