题目描述
You are given a permutation$^\dagger$ $a$ of size $n$. You can do the following operation
- Select an index $i$ from $2$ to $n - 1$ such that $a_{i - 1} < a_i$ and $a_i > a_{i+1}$. Swap $a_i$ and $a_{i+1}$.
Determine whether it is possible to sort the permutation after a finite number of operations.
$^\dagger$ A permutation is an array consisting of $n$ distinct integers from $1$ to $n$ in arbitrary order. For example, $[2,3,1,5,4]$ is a permutation, but $[1,2,2]$ is not a permutation ($2$ appears twice in the array) and $[1,3,4]$ is also not a permutation ($n=3$ but there is $4$ in the array).
Input
Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 5000$). Description of the test cases follows.
The first line of each test case contains a single integer $n$ ($3 \le n \le 10$) — the size of the permutation.
The second line of each test case contains $n$ integers $a_1, a_2, \ldots, a_n$ ($1 \le a_i \le n$) — the elements of permutation $a$.
Output
For each test case, print "YES" if it is possible to sort the permutation, and "NO" otherwise.
You may print each letter in any case (for example, "YES", "Yes", "yes", "yEs" will all be recognized as positive answer).
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
In the first test case, the permutation is already sorted.
In the second test case, we can choose index $i=2$ as $1<3$ and $3>2$ to form $[1, 2, 3, 5, 4]$. Then, we can choose index $i=4$ as $3<5$ and $5>4$ to form $[1, 2, 3, 4, 5]$.
In the third test case, it can be proven that it is impossible to sort the permutation.