代码：

#include <bits/stdc++.h>
using namespace std;
int a[100010], pos[100010], p[100010], q[100010];
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    int t;
    cin >> t;
    while (t--)
    {
        int n;
        cin >> n;
        for (int i = 1; i <= n; i++)
        {
            int x;
            cin >> x;
            a[x] = i;
            pos[a[x]] = x;
        }
        int cnt = 0;
        for (int i = 1; i <= n; i++)
        {
            p[i] = (i + cnt) % n + 1;
            q[pos[p[i]]] = i;
            if (q[pos[p[i]]] == pos[p[i]]) cnt++;
        }
        if (cnt >= n - 1)
        {
            cout << "Impossible" << endl;
            continue;
        }
        for (int i = 1; i <= n; i++)
        {
            p[i] = (i + cnt) % n + 1;
            q[pos[p[i]]] = i; 
        }
        cout << "Possible" << endl;
        for (int i = 1; i <= n; i++) cout << p[i] << " ";
        cout << endl;
        for (int i = 1; i <= n; i++) cout << q[i] << " ";
        cout << endl;
    }
    return 0;
}