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#9946. 峰值

الإحصائيات

如果一个整数序列 $a_1, a_2, \dots, a_n$ 满足以下条件,则称其为“峰”:存在唯一的整数 $k$,使得 $1 < k < n$,且对于所有 $1 \le i < k$ 满足 $a_i < a_{i+1}$,对于所有 $k < i \le n$ 满足 $a_{i-1} > a_i$。

给定一个整数序列,请判断它是否为“峰”。

输入格式

输入包含多组测试数据。第一行包含一个整数 $T$,表示测试数据的组数。对于每组测试数据:

第一行包含一个整数 $n$ ($3 \le n \le 10^5$),表示序列的长度。 第二行包含 $n$ 个整数 $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 2 \times 10^9$),表示该整数序列。

保证所有测试数据中 $n$ 的总和不超过 $10^6$。

输出格式

对于每组测试数据,输出一行。如果给定的整数序列是“峰”,输出 “Yes”(不含引号),否则输出 “No”(不含引号)。

样例

样例输入 1

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

样例输出 1

Yes
No
No
No
Yes
No
No

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