Torni

#include <bits/stdc++.h>
using namespace std;
const int N = 1e6;
const int M = 1e9+7;
long dp[N+1][2];
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  dp[1][0] = 1;
  dp[1][1] = 1;
  for (int i = 2; i <= N; ++i) {
    dp[i][0] = (2*dp[i-1][0] + dp[i-1][1])%M;
    dp[i][1] = (dp[i-1][0] + 4*dp[i-1][1])%M;
  }
  int T;
  cin >> T;
  for (int Ti = 0; Ti < T; ++Ti) {
    int n;
    cin >> n;
    cout << (dp[n][0]+dp[n][1])%M << endl;
  }
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: ACCEPTED