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

#define int long long
#define endl '\n'

#ifdef DEBUG
#define debug(x) cerr << #x << ": " << x << endl;
#else
#define debug(x)
#endif

const int MOD = 1e9 + 7;
int n, m, t;
const int N = 2e6 + 5;
int A[N];

void solve() {
  cin >> n;
  vector<int> a(n);
  int pre = 0;
  for (int &it : a) {
    cin >> it;
  }
  if (a[0] != 0 || a[n - 1] != n - 1) {
    cout << "0\n";
    return;
  }
  for (int i = 1; i < n; ++i) {
    if (a[i] < a[i - 1] || a[i] < i - 1) {
      cout << "0\n";
      return;
    }
  }
  int cur = a[0], cnt = 1, ans = 1;
  for (int i = 1; i < n; ++i) {
    if (a[i] > cur) {
      ans = 2 * ans % MOD;
      cur = a[i];
    } else {
      cur = a[i], cnt = 0;
      while (i < n && a[i] == cur) {
        ++cnt, ++i;
      }
      ans = ans * A[cnt] % MOD;
    }
  }
  cout << ans << endl;
}

signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0), cout.tie(0), cerr.tie(0);

  int tmp = 1;
  for (int i = 1; i <= (int)2e6; ++i) {
    tmp = tmp * i % MOD;
    A[i] = tmp;
  }
  // cerr << A[4];

  cin >> t;
  while (t--)
    solve();
}