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QOJ

Time Limit: 1 s Memory Limit: 128 MB Total points: 100

#3117. 循环反单调排列

Statistics

排列是指一个包含从 $1$ 到 $n$ 每个整数恰好一次的序列。在本题中,我们寻找具有特殊性质的排列:

  1. 反单调性(Antimonotonic):对于每三个连续的值 $p_{i-1}, p_i, p_{i+1}$(其中 $1 < i < n$),$p_i$ 必须是这三个值中的最小值或最大值。
  2. 循环性(Cyclic):该排列应仅由一个循环组成,即当我们使用 $p_i$ 作为从 $i$ 指向 $p_i$ 的指针时,从位置 $1$ 出发,沿着指针移动,应当能够遍历所有 $n$ 个位置,最后回到位置 $1$。

输入格式

输入文件包含多个测试用例。每个测试用例包含一行,为一个整数 $n$($3 \le n \le 10^6$),表示排列中整数的个数。输入以 $n=0$ 结束。

输出格式

对于每个测试用例,输出一个既满足反单调性又满足循环性的 $1$ 到 $n$ 的排列。如果存在多个解,输出其中任意一个即可。用空格分隔所有整数。

样例

样例输入 1

3
5
10
0

样例输出 1

3 1 2
4 5 2 3 1
6 10 2 9 3 5 4 7 1 8

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