CF1352G.Special Permutation

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

A permutation of length nn is an array p=[p1,p2,,pn]p=[p_1,p_2,\dots,p_n] , which contains every integer from 11 to nn (inclusive) and, moreover, each number appears exactly once. For example, p=[3,1,4,2,5]p=[3,1,4,2,5] is a permutation of length 55 .

For a given number nn ( n2n \ge 2 ), find a permutation pp in which absolute difference (that is, the absolute value of difference) of any two neighboring (adjacent) elements is between 22 and 44 , inclusive. Formally, find such permutation pp that 2pipi+142 \le |p_i - p_{i+1}| \le 4 for each ii ( 1i<n1 \le i < n ).

Print any such permutation for the given integer nn or determine that it does not exist.

输入格式

The first line contains an integer tt ( 1t1001 \le t \le 100 ) — the number of test cases in the input. Then tt test cases follow.

Each test case is described by a single line containing an integer nn ( 2n10002 \le n \le 1000 ).

输出格式

Print tt lines. Print a permutation that meets the given requirements. If there are several such permutations, then print any of them. If no such permutation exists, print -1.

输入输出样例

  • 输入#1

    6
    10
    2
    4
    6
    7
    13

    输出#1

    9 6 10 8 4 7 3 1 5 2 
    -1
    3 1 4 2 
    5 3 6 2 4 1 
    5 1 3 6 2 4 7 
    13 9 7 11 8 4 1 3 5 2 6 10 12
首页