Sort Zero

题意翻译

你将会得到一个正整数 $n$ 与 $n$ 个正整数 $a_1,a_2,...,a_n$。$(1\le n\le10^5,1\le a_i\le n)$ 每一次你可以做以下操作： 1. 选择一个正整数 $x$ 2. 将所有等于 $x$ 的数改为 $0$ 输出满足 $\forall i,a_{i-1}\le a_i$ 的最少操作次数。

题目描述

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.

输入输出格式

输入格式

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 $ .

输出格式

For each test case print one integer — the minimum number of operations required to sort the array in non-decreasing order.

输入输出样例

输入样例 #1

5
3
3 3 2
4
1 3 1 3
5
4 1 5 3 2
4
2 4 1 2
1
1

输出样例 #1

1
2
4
3
0

说明

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] $ .

题意翻译

你将会得到一个正整数 $n$ 与 $n$ 个正整数 $a_1,a_2,...,a_n$。$(1\le n\le10^5,1\le a_i\le n)$ 每一次你可以做以下操作： 1. 选择一个正整数 $x$ 2. 将所有等于 $x$ 的数改为 $0$ 输出满足 $\forall i,a_{i-1}\le a_i$ 的最少操作次数。