矩阵快速幂模板

struct Matrix{
    int mat[maxn][maxn];
};

int n, k;

Matrix Matrix_mul(Matrix a, Matrix b){
    Matrix ret;
    memset(ret.mat, 0, sizeof(ret.mat));
    for(int i = 1; i <= k; i++)
    for(int j = 1; j <= k; j++){
        if(a.mat[i][j]){
            for(int kk = 1; kk <= k; kk++)
            ret.mat[i][kk] += (a.mat[i][j]*b.mat[j][kk])%6;
            //ret.mat[i][k] %= 6;
        }
    }
    return ret;
}

Matrix Matrix_pow(Matrix tt, int nn){
    Matrix ret;
    Matrix temp = tt;
    memset(ret.mat, 0, sizeof(ret.mat));
    for(int i = 1; i<= k; i++) ret.mat[i][i] = 1;
    while(nn){
        if(nn&1) ret = Matrix_mul(ret, temp);
        temp = Matrix_mul(temp, temp);
        nn >>= 1;
    }
    return ret;
}