#include <bits/stdc++.h>
using namespace std;
void selectionSort(vector<int> &a,int n){
	for(int i = 0; i < n-1; i++){
		int idx= i;
		for(int j = i + 1;j < n; j++){
			if( a[j] < a[idx]){
				idx = j;
			}
		}
		swap(a[i],a[idx]);
	}
}
void solve() {
    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) cin >> a[i];
    selectionSort(a,n);
    int left = 0, right = n - 1;
    vector<int> res;
    while (left <= right) {
        res.push_back(a[right--]); 
        if (left <= right) {
            res.push_back(a[left++]); 
        }
    }
    for (int num : res) {
        cout << num << " ";
    }
    cout << endl;
}
int main() {
    int t;
    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}