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题意翻译
Bob 有一个 $3 \times n$ 的网格,其中每个单元格包含 $a_i$ 或 $-a_i$,其中 $1 \leq i \leq n$。例如,对于 $n=4$ 的网格可能是:
$$\begin{bmatrix} a_1 & -a_2 & -a_3 & -a_2 \\ -a_4 & a_4 & -a_1 & -a_3 \\ a_1 & a_2 & -a_2 & a_4 \end{bmatrix}$$
Alice 和 Bob 玩一个游戏,规则如下:
- Bob 显示网格给 Alice。
- Alice 选择一个包含 $1$ 或 $-1$ 的数组 $[a_1, a_2, \cdots, a_n]$。
- Bob 用这些值替换网格中的 $a_i$,生成一个只包含 $1$ 和 $-1$ 的网格。
- Bob 对每列的元素进行非降序排序。
- 如果中间一行全是 $1$,则 Alice 获胜;否则 Bob 获胜。
例如,Alice 选择 $[1, -1, -1, 1]$,则结果如下:
$$\begin{bmatrix} 1 & 1 & 1 & 1 \\ -1 & 1 & -1 & 1 \\ 1 & -1 & 1 & 1 \end{bmatrix} \xrightarrow{\text{排序}} \begin{bmatrix} -1 & -1 & -1 & 1 \\ 1 & 1 & 1 & 1 \\ 1 & 1 & 1 & 1 \end{bmatrix}$$
由于中间一行全是 $1$,Alice 获胜。
现在给定 Bob 的网格,确定 Alice 是否可以选择数组 $a$ 来赢得游戏。
Translate by JacoAquamarine
题目描述
Bob has a grid with $ 3 $ rows and $ n $ columns, each of which contains either $ a_i $ or $ -a_i $ for some integer $ 1 \leq i \leq n $ . For example, one possible grid for $ n=4 $ is shown below:
$$\begin{bmatrix} a_1 & -a_2 & -a_3 & -a_2 \\ -a_4 & a_4 & -a_1 & -a_3 \\ a_1 & a_2 & -a_2 & a_4 \end{bmatrix} $$
Alice and Bob play a game as follows:
- Bob shows Alice his grid.
- Alice gives Bob an array $a_1, a_2, \cdots, a_n$ of her choosing, **whose elements are all $-1$ or $1$**.
- Bob substitutes these values into his grid to make a grid of $ -1 $ s and $ 1 $ s.
- Bob **sorts** the elements of each column in non-decreasing order.
- Alice wins if all the elements in the middle row are $ 1 $ ; otherwise, Bob wins.
For example, suppose Alice gives Bob the array $[1, -1, -1, 1]$ for the grid above. Then the following will happen (colors are added for clarity):
$$ \begin{bmatrix} \color{red}{a_1} & \color{green}{-a_2} & \color{blue}{-a_3} & \color{green}{-a_2} \\ -a_4 & a_4 & \color{red}{-a_1} & \color{blue}{-a_3} \\ \color{red}{a_1} & \color{green}{a_2} & \color{green}{-a_2} & a_4 \end{bmatrix} \xrightarrow{[\color{red}{1},\color{green}{-1},\color{blue}{-1},1]} \begin{bmatrix} \color{red}{1} & \color{green}{1} & \color{blue}{1} & \color{green}{1} \\ -1 & 1 & \color{red}{-1} & \color{blue}{1} \\ \color{red}{1} & \color{green}{-1} & \color{green}{1} & 1 \end{bmatrix} \xrightarrow{\text{sort each column}} \begin{bmatrix} -1 & -1 & -1 & 1 \\ \mathbf{1} & \mathbf{1} & \mathbf{1} & \mathbf{1} \\ 1 & 1 & 1 & 1 \\ \end{bmatrix}$$
Since the middle row is all $ 1 $ , Alice wins. Given Bob's grid, determine whether or not Alice can choose the array $a$ to win the game.
输入输出格式
输入格式
The first line contains a single integer $ t $ ( $ 1 \leq t \leq 1000 $ ) — the number of test cases.
The first line of each test case contains a single integer $ n $ ( $ 2 \leq n \leq 500 $ ) — the number of columns of Bob's grid.
The next three lines each contain $ n $ integers, the $ i $ -th of which contains $ g_{i,1}, g_{i,2}, \dots, g_{i,n} $ ( $ -n \leq g_{i,j} \leq n $ , $ g_{i,j} \neq 0 $ ), representing Bob's grid.
If cell $ x > 0 $ is in the input, that cell in Bob's grid should contain $ a_x $ ; if $ x < 0 $ is in the input, that cell in Bob's grid should contain $ -a_{-x} $ . See the sample input and notes for a better understanding.
输出格式
For each test case, output `YES` (without quotes) if Alice can win, and `NO` (without quotes) otherwise.
You can output `YES` and `NO` in any case (for example, strings `yEs`, `yes`, and `Yes` will be recognized as a positive response).
输入输出样例
输入样例 #1
4
4
1 -2 -3 -2
-4 4 -1 -3
1 2 -2 4
2
1 2
-1 -2
2 -2
5
1 2 3 4 5
-2 3 -4 -5 -1
3 -5 1 2 2
6
1 3 -6 2 5 2
1 3 -2 -3 -6 -5
-2 -1 -3 2 3 1
输出样例 #1
YES
NO
YES
NO
说明
The first test case is described in the statement.
In the second test case, Bob's grid is as follows:
$$\begin{bmatrix} a_1 & a_2 \\ -a_1 & -a_2 \\ a_2 & -a_2 \end{bmatrix} $$
For the last column to have $ 1 $ in the middle row when sorted, Alice must pick $ a_2 = -1 $ . However, it is then impossible to choose $ a_1 $ such that the first column has $ 1 $ in the middle when sorted. Thus, Alice cannot win.
In the third test case, Alice can pick $ a = [1,1,1,1,1]$.