Torni

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

ll M = 1e9 + 7;

ll pot[1010101];
ll dp[1010101][2];

void testCase() {
    ll n;
    cin >> n;
    cout << (dp[n][0] + dp[n][1])%M << "\n";
}
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    
    pot[0] = 1;
    for (int i = 1; i <= 1e6; i++) {
        pot[i] = 2*pot[i-1];
        pot[i] %= M;
    }
    ll sum = 1;
    dp[0][0] = 1;
    for (int i = 1; i <= 1e6; i++) {
        dp[i][0] = sum;
        dp[i][1] = 4*dp[i-1][1] + dp[i-1][0];
        dp[i][1] %= M;
        sum += dp[i][0] + dp[i][1];
        sum %= M;
    }
    int t;
    cin >> t;
    for (int i = 0; i < t; i++) {
        testCase();
    }
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: ACCEPTED