1 /**
  2  * code generated by JHelper
  3  * More info: https://github.com/AlexeyDmitriev/JHelper
  4  * @author xyiyy @https://github.com/xyiyy
  5  */
  6 
  7 #include <iostream>
  8 #include <fstream>
  9 
 10 //#####################
 11 //Author:fraud
 12 //Blog: http://www.cnblogs.com/fraud/
 13 //#####################
 14 //#pragma comment(linker, "/STACK:102400000,102400000")
 15 #include <iostream>
 16 #include <sstream>
 17 #include <ios>
 18 #include <iomanip>
 19 #include <functional>
 20 #include <algorithm>
 21 #include <vector>
 22 #include <string>
 23 #include <list>
 24 #include <queue>
 25 #include <deque>
 26 #include <stack>
 27 #include <set>
 28 #include <map>
 29 #include <cstdio>
 30 #include <cstdlib>
 31 #include <cmath>
 32 #include <cstring>
 33 #include <climits>
 34 #include <cctype>
 35 
 36 using namespace std;
 37 #define mp(X, Y) make_pair(X,Y)
 38 #define pb(X) push_back(X)
 39 #define rep(X, N) for(int X=0;X<N;X++)
 40 #define rep2(X, L, R) for(int X=L;X<=R;X++)
 41 typedef pair<int, int> PII;
 42 
 43 typedef pair<PII, int> PIII;
 44 priority_queue<PIII, vector<PIII>, greater<PIII> > q;
 45 int f[100010];
 46 int l[100010];
 47 int r[100010];
 48 vector<int> v[100010];
 49 
 50 class hdu5360 {
 51 public:
 52     void solve(std::istream &in, std::ostream &out) {
 53         int n;
 54         in >> n;
 55         for (int i = 1; i <= n; i++)in >> l[i];
 56         for (int i = 1; i <= n; i++) {
 57             in >> r[i];
 58             if (l[i])v[l[i]].pb(i);
 59             else q.push(mp(mp(r[i], l[i]), i));
 60         }
 61         int num = n;
 62         int ans = 0;
 63         int sz = 0;
 64         while (n) {
 65             if (q.empty()) {
 66                 rep2(i, ans + 1, n) {
 67                     rep(j, v[i].size()) {
 68                         f[sz++] = v[i][j];
 69                     }
 70                     v[i].clear();
 71                 }
 72                 break;
 73             }
 74             PIII p = q.top();
 75             q.pop();
 76             int y = p.first.first;
 77             int x = p.first.second;
 78             int z = p.second;
 79             f[sz++] = z;
 80             if (x <= ans && y >= ans) {
 81                 ans++;
 82                 rep(i, v[ans].size()) {
 83                     int j = v[ans][i];
 84                     q.push(mp(mp(r[j], l[j]), j));
 85                 }
 86                 v[ans].clear();
 87             }
 88         }
 89         out << ans << endl;
 90         rep(i, sz) {
 91             if (i)out << " ";
 92             out << f[i];
 93         }
 94         out << endl;
 95     }
 96 };
 97 
 98 int main() {
 99     std::ios::sync_with_stdio(false);
100     std::cin.tie(0);
101     hdu5360 solver;
102     std::istream &in(std::cin);
103     std::ostream &out(std::cout);
104     int n;
105     in >> n;
106     for (int i = 0; i < n; ++i) {
107         solver.solve(in, out);
108     }
109 
110     return 0;
111 }