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
1
6
Sample Output
1 3 2 6 4 5
题意：
pi%(|pi-pi-2|）==0。
题解：
很简单。看代码就好了。
#include<iostream>
using namespace std;
int main()
{
int t;
cin>>t;
while(t--)
{
int n;
cin>>n;
int lb=1,ub=(n+1)/2+1;
while(1)
{
if(lb<=(n+1)/2)
cout<<lb++<<' ';
else
break;
if(ub<=n)
cout<<ub++<<' ';
else
break;
}
cout<<endl;
}
return 0;
}