CF1856A.Tales of a Sort

普及/提高-

通过率：0%

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题目描述

Alphen has an array of positive integers $a$ of length $n$ .

Alphen can perform the following operation:

For all $i$ from $1$ to $n$ , replace $a_i$ with $\max(0, a_i - 1)$ .

Alphen will perform the above operation until $a$ is sorted, that is $a$ satisfies $a_1 \leq a_2 \leq \ldots \leq a_n$ . How many operations will Alphen perform? Under the constraints of the problem, it can be proven that Alphen will perform a finite number of operations.

输入格式

Each test contains multiple test cases. The first line of input contains a single integer $t$ ( $1 \le t \le 500$ ) — the number of test cases. The description of the test cases follows.

The first line of each test case contains a single integer $n$ ( $2 \le n \le 50$ ) — the length of the array $a$ .

The second line of each test case contains $n$ integers $a_1, a_2, \dots, a_n$ ( $1 \le a_i \le 10 ^ 9$ ) — the elements of the array $a$ .

输出格式

For each test case, output a single integer — the number of operations that Alphen will perform.

输入输出样例

输入#1

7
3
1 2 3
5
2 1 2 1 2
4
3 1 5 4
2
7 7
5
4 1 3 2 5
5
2 3 1 4 5
3
1000000000 1 2

输出#1

说明/提示

In the first test case, we have $a=[1,2,3]$ . Since $a$ is already sorted, Alphen will not need to perform any operations. So, the answer is $0$ .

In the second test case, we have $a=[2,1,2,1,2]$ . Since $a$ is not initially sorted, Alphen will perform one operation to make $a=[1,0,1,0,1]$ . After performing one operation, $a$ is still not sorted, so Alphen will perform another operation to make $a=[0,0,0,0,0]$ . Since $a$ is sorted, Alphen will not perform any other operations. Since Alphen has performed two operations in total, the answer is $2$ .

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