Torni

#include <bits/stdc++.h>
#define ll long long int
 
using namespace std;
 
int M = 1e9+7;
vector<ll> k(1000001,0);
 
ll f(int a)
{
	if(a<0) return 0;
	if(k[a]) return k[a];
 
 	int x = (6*f(a-1))%M;
	int y = (7*f(a-2))%M;
 	k[a] = (x-y+M)%M;
 
	return k[a];
}
 
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
 
 
	k[0] = 1;
	k[1] = 2;
	k[2] = 8;
 
 
	int t; cin >> t;
 
	while(t--)
	{
		int n; cin >> n;
		cout << f(n) << "\n";
	}
 
 
	return 0;
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: ACCEPTED