CF1413A.Finding Sasuke

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题目描述

Naruto has sneaked into the Orochimaru's lair and is now looking for Sasuke. There are TT rooms there. Every room has a door into it, each door can be described by the number nn of seals on it and their integer energies a1a_1 , a2a_2 , ..., ana_n . All energies aia_i are nonzero and do not exceed 100100 by absolute value. Also, nn is even.

In order to open a door, Naruto must find such nn seals with integer energies b1b_1 , b2b_2 , ..., bnb_n that the following equality holds: a1b1+a2b2+...+anbn=0a_{1} \cdot b_{1} + a_{2} \cdot b_{2} + ... + a_{n} \cdot b_{n} = 0 . All bib_i must be nonzero as well as aia_i are, and also must not exceed 100100 by absolute value. Please find required seals for every room there.

输入格式

The first line contains the only integer TT ( 1T10001 \leq T \leq 1000 ) standing for the number of rooms in the Orochimaru's lair. The other lines contain descriptions of the doors.

Each description starts with the line containing the only even integer nn ( 2n1002 \leq n \leq 100 ) denoting the number of seals.

The following line contains the space separated sequence of nonzero integers a1a_1 , a2a_2 , ..., ana_n ( ai100|a_{i}| \leq 100 , ai0a_{i} \neq 0 ) denoting the energies of seals.

输出格式

For each door print a space separated sequence of nonzero integers b1b_1 , b2b_2 , ..., bnb_n ( bi100|b_{i}| \leq 100 , bi0b_{i} \neq 0 ) denoting the seals that can open the door. If there are multiple valid answers, print any. It can be proven that at least one answer always exists.

输入输出样例

  • 输入#1

    2
    2
    1 100
    4
    1 2 3 6

    输出#1

    -100 1
    1 1 1 -1

说明/提示

For the first door Naruto can use energies [100,1][-100, 1] . The required equality does indeed hold: 1(100)+1001=01 \cdot (-100) + 100 \cdot 1 = 0 .

For the second door Naruto can use, for example, energies [1,1,1,1][1, 1, 1, -1] . The required equality also holds: 11+21+31+6(1)=01 \cdot 1 + 2 \cdot 1 + 3 \cdot 1 + 6 \cdot (-1) = 0 .

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