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A15090. Max GEQ Sum

编程题 普及/提高-

题目描述

You are given an array $a$ of $n$ integers. You are asked to find out if the inequality $\max(a_i, a_{i + 1}, \ldots, a_{j - 1}, a_{j}) \geq a_i + a_{i + 1} + \dots + a_{j - 1} + a_{j}$ holds for all pairs of indices $(i, j)$ , where $1 \leq i \leq j \leq n$.

输入格式

Each test contains multiple test cases. The first line contains the number of test cases $t$ ( $1 \le t \le 10^5$ ). Description of the test cases follows.

The first line of each test case contains a single integer $n$ ( $1 \leq n \leq 2 \cdot 10^5$ ) — the size of the array.

The next line of each test case contains $n$ integers $a_1, a_2, \ldots, a_n$ ( $-10^9 \le a_i \le 10^9$ ).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$ .

输出格式

For each test case, on a new line output "YES" if the condition is satisfied for the given array, and "NO" otherwise. You can print each letter in any case (upper or lower).

输入输出样例

输入 #1
3
4
-1 1 -1 2
5
-1 2 -3 2 -1
3
2 3 -1
输出 #1
YES
YES
NO

说明/提示

In test cases $1$ and $2$ , the given condition is satisfied for all $(i, j)$ pairs.

In test case $3$ , the condition isn't satisfied for the pair $(1, 2)$ as $\max(2, 3) < 2 + 3$ .
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