#line 1 "main.cpp"
#include <bits/stdc++.h>
using namespace std;

// template {{{
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;

#define  range(i, l, r) for (i64 i = (i64)(l); i < (i64)(r); (i) += 1)
#define rrange(i, l, r) for (i64 i = (i64)(r) - 1; i >= (i64)(l); (i) -= 1)

#define  whole(f, x, ...) ([&](decltype((x)) container) { return (f)(  begin(container),  end(container), ## __VA_ARGS__); })(x)
#define rwhole(f, x, ...) ([&](decltype((x)) container) { return (f)( rbegin(container), rend(container), ## __VA_ARGS__); })(x)

#define debug(x) cerr << "(" << __LINE__ << ")" << #x << ": " << (x) << endl

constexpr i32 inf   = 1001001001;
constexpr i64 infll = 1001001001001001001ll;

constexpr i32 dx[] = {0, -1, 1, 0, -1, 1, -1, 1}; 
constexpr i32 dy[] = {-1, 0, 0, 1, -1, -1, 1, 1};

struct IoSetup { IoSetup(i32 x = 15){ cin.tie(0); ios::sync_with_stdio(0); cout << fixed << setprecision(x); cerr << fixed << setprecision(x); } } iosetup;

template <typename T = i64> T input() { T x; cin >> x; return x; }

template <typename T> ostream &operator<<(ostream &os, vector<T> &v) { range(i, 0, v.size()) { os << v[i] << (i + 1 != (int)v.size() ? " " : ""); } return os; } 
template <typename T> istream &operator>>(istream &is, vector<T> &v) { for (T &in : v) is >> in; return is; }

template <typename T1, typename T2> ostream &operator<<(ostream &os, pair<T1, T2> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
template <typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &p) { is >> p.first >> p.second; return is; }

template <typename T> vector<T> make_vector(size_t a, T b) { return vector<T>(a, b); }
template <typename... Ts> auto make_vector(size_t a, Ts... ts) { return vector<decltype(make_vector(ts...))>(a, make_vector(ts...)); }

template <typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template <typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }
// }}}

vector< int > calc(int n, vector< int > ps) {
  vector< int > res;
  for (auto &p : ps) {
    p--;
  }

  // v : 0-indexed
  auto find_idx = [&](int v) {
    range(i, 0, n) {
      if (ps[i] == v) return i;
    }
    return -1ll;
  };

  int k = 0;

  auto swap_check = [&](int i) {
    return ((i & 1) == (k & 1));
  };

  auto swap_query = [&](int i) {
    // if ((i + k) % 2 != 0) return;
    swap(ps[i], ps[i + 1]);
    k++;
    res.emplace_back(i + 1);
  };

  rrange(v, 0, n) {
    int idx = find_idx(v);
    if (idx == v) continue;

    while (not swap_check(idx)) {
      if (idx == (k&1) + 1) idx--;
      swap_query(k & 1);
    }

    range(i, idx, v) {
      swap_query(i);
    }
  }

  if (ps[n-2] != n-2) {
    swap_query(n-2);
  }

  return res;
}

void solve() {
  int t = input();
  while (t--) {
    int n = input();
    vector< int > ps(n);
    cin >> ps;
    auto as = calc(n, ps);
    cout << as.size() << endl;
    cout << as << endl;
  }
}

signed main() {
  solve();
}

#include <bits/stdc++.h>
using namespace std;

typedef unsigned long long ull;
typedef long long int lli;
typedef vector<int> vi;
typedef vector<long long int> vlli;

#define pb push_back
#define pi 3.1415

const lli MOD= 1e9+7;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    int n;cin>>n;
    vi A(n),B(n);
    for(auto &a:A)
        cin>>a;
    
    for(auto &b:B)
        cin>>b;

    cout<<max(0,*min_element(B.begin(),B.end())-*max_element(A.begin(),A.end())+1)<<"\n";
    return 0;
}