310169: CF1792C. Min Max Sort

Memory Limit:256 MB Time Limit:2 S
Judge Style:Text Compare Creator:
Submit:0 Solved:0

Description

Min Max Sort

题意翻译

## 题目描述 对于一个排列,定义一次操作为:在排列中任选两个数字,将它们中的最大值插入至队尾,最小值插入至队首。 现在给定多个排列,问每个排列最少各需多少次操作才能变得严格递增。 ## 输入格式 第一行一个整数 $t(1 \le t \le 10^4)$,表示将要给出的排列数。 接下来 $2t$ 行,每两行描述一个排列:首行一个整数 $n(1 \le n \le 2 \times 10^5)$,表示排列的长度;下一行 $n$ 个整数,描述排列 $p$。 保证 $\sum n \le 2 \times 10^5$。 ## 输出格式 $t$ 行,每行一个整数,表示使第 $i$ 个排列变得严格递增所需要的操作数。

题目描述

You are given a permutation $ p $ of length $ n $ (a permutation of length $ n $ is an array of length $ n $ in which each integer from $ 1 $ to $ n $ occurs exactly once). You can perform the following operation any number of times (possibly zero): 1. choose two different elements $ x $ and $ y $ and erase them from the permutation; 2. insert the minimum of $ x $ and $ y $ into the permutation in such a way that it becomes the first element; 3. insert the maximum of $ x $ and $ y $ into the permutation in such a way that it becomes the last element. For example, if $ p = [1, 5, 4, 2, 3] $ and we want to apply the operation to the elements $ 3 $ and $ 5 $ , then after the first step of the operation, the permutation becomes $ p = [1, 4, 2] $ ; and after we insert the elements, it becomes $ p = [3, 1, 4, 2, 5] $ . Your task is to calculate the minimum number of operations described above to sort the permutation $ p $ in ascending order (i. e. transform $ p $ so that $ p_1 < p_2 < \dots < p_n $ ).

输入输出格式

输入格式


The first line contains a single integer $ t $ ( $ 1 \le t \le 10^4 $ ) — the number of test cases. The first line of the test case contains a single integer $ n $ ( $ 1 \le n \le 2 \cdot 10^5 $ ) — the number of elements in the permutation. The second line of the test case contains $ n $ distinct integers from $ 1 $ to $ n $ — the given permutation $ p $ . The sum of $ n $ over all test cases doesn't exceed $ 2 \cdot 10^5 $ .

输出格式


For each test case, output a single integer — the minimum number of operations described above to sort the array $ p $ in ascending order.

输入输出样例

输入样例 #1

4
5
1 5 4 2 3
3
1 2 3
4
2 1 4 3
6
5 2 4 1 6 3

输出样例 #1

2
0
1
3

说明

In the first example, you can proceed as follows: 1. in the permutation $ p = [1, 5, 4, 2, 3] $ , let's choose the elements $ 4 $ and $ 2 $ , then, after applying the operation, the permutation becomes $ p = [2, 1, 5, 3, 4] $ ; 2. in the permutation $ p = [2, 1, 5, 3, 4] $ , let's choose the elements $ 1 $ and $ 5 $ , then, after applying operation, the permutation becomes $ p = [1, 2, 3, 4, 5] $ .

Input

题意翻译

## 题目描述 对于一个排列,定义一次操作为:在排列中任选两个数字,将它们中的最大值插入至队尾,最小值插入至队首。 现在给定多个排列,问每个排列最少各需多少次操作才能变得严格递增。 ## 输入格式 第一行一个整数 $t(1 \le t \le 10^4)$,表示将要给出的排列数。 接下来 $2t$ 行,每两行描述一个排列:首行一个整数 $n(1 \le n \le 2 \times 10^5)$,表示排列的长度;下一行 $n$ 个整数,描述排列 $p$。 保证 $\sum n \le 2 \times 10^5$。 ## 输出格式 $t$ 行,每行一个整数,表示使第 $i$ 个排列变得严格递增所需要的操作数。

Output

**最小最大排序**

题目描述:
对于一个排列,定义一次操作为:在排列中任选两个数字,将它们中的最大值插入至队尾,最小值插入至队首。

现在给定多个排列,问每个排列最少各需多少次操作才能变得严格递增。

输入格式:
第一行一个整数 $ t(1 \le t \le 10^4) $,表示将要给出的排列数。

接下来 $ 2t $ 行,每两行描述一个排列:首行一个整数 $ n(1 \le n \le 2 \times 10^5) $,表示排列的长度;下一行 $ n $ 个整数,描述排列 $ p $。

保证 $ \sum n \le 2 \times 10^5 $。

输出格式:
$ t $ 行,每行一个整数,表示使第 $ i $ 个排列变得严格递增所需要的操作数。

题目描述(英文):
You are given a permutation $ p $ of length $ n $ (a permutation of length $ n $ is an array of length $ n $ in which each integer from $ 1 $ to $ n $ occurs exactly once).

You can perform the following operation any number of times (possibly zero):

1. choose two different elements $ x $ and $ y $ and erase them from the permutation;
2. insert the minimum of $ x $ and $ y $ into the permutation in such a way that it becomes the first element;
3. insert the maximum of $ x $ and $ y $ into the permutation in such a way that it becomes the last element.

For example, if $ p = [1, 5, 4, 2, 3] $ and we want to apply the operation to the elements $ 3 $ and $ 5 $, then after the first step of the operation, the permutation becomes $ p = [1, 4, 2] $; and after we insert the elements, it becomes $ p = [3, 1, 4, 2, 5]$.

Your task is to calculate the minimum number of operations described above to sort the permutation $ p $ in ascending order (i.e. transform $ p $ so that $ p_1 < p_2 < \dots < p_n $).

输入输出格式:
输入格式:
The first line contains a single integer $ t (1 \le t \le 10^4) $ — the number of test cases.

The first line of the test case contains a single integer $ n (1 \le n \le 2 \cdot 10^5) $ — the number of elements in the permutation.

The second line of the test case contains $ n $ distinct integers from $ 1 $ to $ n $ — the given permutation $ p $.

The sum of $ n $ over all test cases doesn't exceed $ 2 \cdot 10^5 $.

输出格式:
For each test case, output a single integer — the minimum number of operations described above to sort the array $ p $ in ascending order.**最小最大排序** 题目描述: 对于一个排列,定义一次操作为:在排列中任选两个数字,将它们中的最大值插入至队尾,最小值插入至队首。 现在给定多个排列,问每个排列最少各需多少次操作才能变得严格递增。 输入格式: 第一行一个整数 $ t(1 \le t \le 10^4) $,表示将要给出的排列数。 接下来 $ 2t $ 行,每两行描述一个排列:首行一个整数 $ n(1 \le n \le 2 \times 10^5) $,表示排列的长度;下一行 $ n $ 个整数,描述排列 $ p $。 保证 $ \sum n \le 2 \times 10^5 $。 输出格式: $ t $ 行,每行一个整数,表示使第 $ i $ 个排列变得严格递增所需要的操作数。 题目描述(英文): You are given a permutation $ p $ of length $ n $ (a permutation of length $ n $ is an array of length $ n $ in which each integer from $ 1 $ to $ n $ occurs exactly once). You can perform the following operation any number of times (possibly zero): 1. choose two different elements $ x $ and $ y $ and erase them from the permutation; 2. insert the minimum of $ x $ and $ y $ into the permutation in such a way that it becomes the first element; 3. insert the maximum of $ x $ and $ y $ into the permutation in such a way that it becomes the last element. For example, if $ p = [1, 5, 4, 2, 3] $ and we want to apply the operation to the elements $ 3 $ and $ 5 $, then after the first step of the operation, the permutation becomes $ p = [1, 4, 2] $; and after we insert the elements, it becomes $ p = [3, 1, 4, 2, 5]$. Your task is to calculate the minimum number of operations described above to sort the permutation $ p $ in ascending order (i.e. transform $ p $ so that $ p_1 < p_2 < \dots < p_n $). 输入输出格式: 输入格式: The first line contains a single integer $ t (1 \le t \le 10^4) $ — the number of test cases. The first line of the test case contains a single integer $ n (1 \le n \le 2 \cdot 10^5) $ — the number of elements in the permutation. The second line of the test case contains $ n $ distinct integers from $ 1 $ to $ n $ — the given permutation $ p $. The sum of $ n $ over all test cases doesn't exceed $ 2 \cdot 10^5 $. 输出格式: For each test case, output a single integer — the minimum number of operations described above to sort the array $ p $ in ascending order.

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