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OI-codes/Luogu/P1939/P1939.cpp

86 lines
1.4 KiB
C++

#include <iostream>
#include <cstring>
using std::cin;
using std::cout;
const char endl = '\n';
const int N = 10;
const int mod = 1e9 + 7;
class Matrix {
private:
int data[N][N];
public:
Matrix() {
memset(data, 0x00, sizeof(data));
}
int* operator[](int i) {
return data[i];
}
void build() {
int n = 3;
for (int i = 1; i <= n; i++) {
data[i][i] = 1;
}
}
Matrix operator*(Matrix b) const {
Matrix c;
int n = 3;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
for (int k = 1; k <= n; k++) {
c[i][j] = (c[i][j] + 1ll * data[i][k] * b[k][j] % mod) % mod;
}
}
}
return c;
}
};
Matrix binpow(Matrix a, int k) {
Matrix res;
res.build();
while (k) {
if (k & 1) res = res * a;
a = a * a;
k >>= 1;
}
return res;
}
int t, n;
int main() {
std::ios::sync_with_stdio(false);
cin >> t;
Matrix base, pow;
base[1][1] = 1;
base[2][1] = 1;
base[3][1] = 1;
pow[1][1] = 1, pow[1][2] = 0, pow[1][3] = 1;
pow[2][1] = 1, pow[2][2] = 0, pow[2][3] = 0;
pow[3][1] = 0, pow[3][2] = 1, pow[3][3] = 0;
while (t--) {
cin >> n;
cout << (base * binpow(pow, n - 1))[1][1] << endl;
}
return 0;
}