B. Best Permutation.cpp

#include <bits/stdc++.h>

using namespace std;

int t, n, ans[105];

int main(){
    cin.tie(nullptr), ios::sync_with_stdio(false);
    cin >> t;
    while(t--){
        cin >> n;
        for(int i = 1; i <= n; i++) ans[i] = i;
        for(int i = n - 2; i > 1; i -= 2) swap(ans[i - 1], ans[i]);
        for(int i = 1; i <= n; i++) cout << ans[i] << " ";
        cout << "\n";
    }
}