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Time Limit: 1 s Memory Limit: 256 MB Total points: 100

#11563. Convex Array

統計

你得到一个长度为 $n$ 的整数数组 $a$。

判断是否存在一个它的排列 $b$,使得对于每个 $2\leq i \leq n-1$,都有 $b_{i-1} + b_{i+1} \ge 2\cdot b_i$ 成立。

本题中,每个测试包含若干组输入数据。你需要对每组数据独立地解决问题。

输入

第一行包含一个整数 $T$ $(1\le T\le 10^5)$~--- 输入数据组数。接下来是每组输入数据的描述。

每组输入数据的第一行是一个整数 $n$ $(3\le n\le 3\cdot 10^5)$~--- 数组 $a$ 的长度。

每组输入数据的第二行是 $n$ 个整数 $a_1, a_2, \ldots, a_n$ $(0\le a_i\le 10^9)$~--- 数组 $a$ 的元素。

保证单个测试中所有输入数据组的 $n$ 之和不超过 $3\cdot 10^5$。

输出

对于每组输入数据,输出一行 YES,如果存在满足要求的排列;否则输出 NO

示例

输入

10
4
0 3 4 6
4
5 4 1 4
8
1 4 4 8 6 10 10 4
7
2 1 5 1 9 4 6
6
7 1 6 10 2 3
7
6 6 10 2 5 3 8
4
9 9 1 5
4
8 4 3 4
7
1 2 1 6 4 2 9
7
3 9 7 5 9 10 10

输出

YES
NO
NO
YES
YES
NO
YES
YES
YES
NO

说明

在第一个例子中的第一组输入数据中,数组 $[0, 3, 4, 6]\$ 满足条件的排列是 $[4, 0, 3, 6]$ 和 $[6, 3, 0, 4]$。

评分

设 $S$ 是单个测试中所有输入数据组的 $n$ 之和。

  1. (3 分):$n = 4$;
  2. (4 分):$T = 1$, $n \le 7$;
  3. (7 分):$T = 1$, $n \le 15$;
  4. (5 分):如果存在某个满足条件的排列,那么一定存在一个满足条件的排列使得 $b_1 \ge b_2$ 且 $b_2 \le b_3$;
  5. (17 分):$S \le 50$;
  6. (10 分):$S \le 400$;
  7. (13 分):$S \le 2000$;
  8. (9 分):$S \le 8000$;
  9. (18 分):对于所有 $1 \le i \le n$,$a_i \le 10^6$;
  10. (14 分):无额外限制。
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