这题不能用矩阵快速幂吗？

#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
#define int unsigned long long
const int N = 4;
struct Matrix {
	int a[N][N];
	Matrix() {
		memset(a, 0, sizeof a);
	}
	Matrix operator * (const Matrix &b) const {
		Matrix res;
		for (int i = 1; i <= N - 1; i++)
			for (int j = 1; j <= N - 1; j++)
				for (int k = 1; k <= N - 1; k++)
					res.a[i][j] = (res.a[i][j] + a[i][k] * b.a[k][j]);
		return res;
	}
} ans, base;
void qpow(long long b) {
	while (b) {
		if (b & 1) ans = ans * base;
		base = base * base;
		b >>= 1;
	}
}
signed main() {
	long long n;
    int uu;
    cin>>uu;
	while (uu--) {
        cin>>n;
		if (n == 1) {
			cout << "1\n";
			continue;
		}
		if (n == 2) {
			cout << "2\n";
			continue;
		}
		memset(base.a, 0, sizeof base.a);
		base.a[1][1] = base.a[1][3] = base.a[3][2] = base.a[3][3] = 1;
		base.a[2][3] = 2;
		ans.a[1][1] = ans.a[1][2] = 1, ans.a[1][3] = 2;
		qpow(n - 2);
		cout << ans.a[1][3] << '\n';
	}
	return 0;
}