#include<bits/stdc++.h>
using namespace std;
using pii = pair<int,int>;
#define fi first
#define se second
void solve()
{
    int n;
    cin>>n;
    vector<int>ar(n + 1),idx(n + 1,-1);
    int res = 0;
    vector<int>p;
    for(int i = 1;i <= n;i ++)
    {
        cin>>ar[i];
        if(ar[i] == i)
            p.push_back(ar[i]);
        else
            idx[ar[i]] = i;
    }
    vector<int>ans;
    for(auto v:p)
        ans.push_back(v);
    for(int i = 1;i <= n;i ++)
    {
        if(idx[i] != -1 && idx[idx[i]] != -1)
        {
            ans.push_back(i);
            ans.push_back(idx[i]);
            idx[idx[i]] = -1;
        }
    }
    for(auto v:ans)
        cout<<v<<" ";
    cout<<"\n";
}
int main()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int T;
    cin>>T;
    while(T --)
        solve();
}