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A14655 | Vupsen, Pupsen and 0

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题目描述

Vupsen and Pupsen were gifted an integer array. Since Vupsen doesn't like the number $0$ , he threw away all numbers equal to $0$ from the array. As a result, he got an array $a$ of length $n$ .

Pupsen, on the contrary, likes the number $0$ and he got upset when he saw the array without zeroes. To cheer Pupsen up, Vupsen decided to come up with another array $b$ of length $n$ such that $\sum_{i=1}^{n}a_i \cdot b_i=0$ . Since Vupsen doesn't like number $0$ , the array $b$ must not contain numbers equal to $0$ . Also, the numbers in that array must not be huge, so the sum of their absolute values cannot exceed $10^9$ . Please help Vupsen to find any such array $b$ !

输入格式

The first line contains a single integer $t$ ( $1 \le t \le 100$ ) — the number of test cases. The next $2 \cdot t$ lines contain the description of test cases. The description of each test case consists of two lines.

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

The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ( $-10^4 \le a_i \le 10^4$ , $a_i \neq 0$ ) — the elements of the array $a$ .

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 print $n$ integers $b_1, b_2, \ldots, b_n$ — elements of the array $b$ ( $|b_1|+|b_2|+\ldots +|b_n| \le 10^9$ , $b_i \neq 0$ , $\sum_{i=1}^{n}a_i \cdot b_i=0$ ).

It can be shown that the answer always exists.

输入输出样例

输入 #1
3
2
5 5
5
5 -2 10 -9 4
7
1 2 3 4 5 6 7
输出 #1
1 -1
-1 5 1 -1 -1
-10 2 2 -3 5 -1 -1
C++ 编辑器
输入
输出