CF1352G.Special Permutation
普及/提高-
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题目描述
A permutation of length n is an array p=[p1,p2,…,pn] , which contains every integer from 1 to n (inclusive) and, moreover, each number appears exactly once. For example, p=[3,1,4,2,5] is a permutation of length 5 .
For a given number n ( n≥2 ), find a permutation p in which absolute difference (that is, the absolute value of difference) of any two neighboring (adjacent) elements is between 2 and 4 , inclusive. Formally, find such permutation p that 2≤∣pi−pi+1∣≤4 for each i ( 1≤i<n ).
Print any such permutation for the given integer n or determine that it does not exist.
输入格式
The first line contains an integer t ( 1≤t≤100 ) — the number of test cases in the input. Then t test cases follow.
Each test case is described by a single line containing an integer n ( 2≤n≤1000 ).
输出格式
Print t 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