HDU

Permutation

Problem Description

A permutation p1,p2,...,pn of 1,2,...,n is called a lucky permutation if and only if pi≡0(mod|pi−pi−2|) for i=3...n.

Now you need to construct a lucky permutation with a given n.

 

Input

The first line is the number of test cases.

For each test case, one single line contains a positive integer n(3≤n≤105).

 

Output

For each test case, output a single line with n numbers p1,p2,...,pn.

It is guaranteed that there exists at least one solution. And if there are different solutions, print any one of them.

 

Sample Input

16

 

Sample Output

1 3 2 6 4 5

 

题意：很简单。要注意是排列，就所有数字只能用一次。

解题思路：任何数模1，都为0.所以……看代码……

#include<iostream>#include<deque>#include<memory.h>#include<stdio.h>#include<map>#include<string.h>#include<algorithm>#include<vector>#include<math.h>#include<stack>#include<queue>#include<set>using namespace std;typedef long long int ll;int a[100005];int main(){    int t;    scanf("%d",&t);    while(t--){        int n;        scanf("%d",&n);        a[1]=1;        if(n%2)            a[2]=n/2+2;        else            a[2]=n/2+1;        for(int i=3;i<=n;i++)            a[i]=a[i-2]+1;        for(int i=1;i<n;i++)            cout<<a[i]<<" ";        cout<<a[n]<<endl;    }    return 0;}