D

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<algorithm>
 4 using namespace std;
 5 const int md=1e9+7;
 6 struct matr
 7 {
 8     int m[3][3];
 9 }a;
10 int n;
11 
12 matr mul(matr a,matr b)
13 {
14     matr c;
15     for (int i=0;i<3;i++)
16     for (int j=0;j<3;j++) {
17         c.m[i][j]=0;
18         for (int k=0;k<3;k++) {
19             c.m[i][j]+=(long long)a.m[i][k]*b.m[k][j]%md;
20             c.m[i][j]%=md;
21         }
22     }
23     return c;
24 }
25 
26 matr qsm(matr a,int b)
27 {
28     matr s;
29     for (int i=0;i<3;i++)
30     for (int j=0;j<3;j++) {
31         s.m[i][j]=(i==j);
32     }
33     while (b) {
34         if (b&1) s=mul(s,a);
35         a=mul(a,a);
36         b>>=1;
37     }
38     return s;
39 }
40 
41 int baoli(int n)
42 {
43     int q=0,r=0;
44     for (int i=1;i<=n;i++) {
45         int _q=q,_r=r;
46         q=(2*_r+1)%md;
47         r=(q+_q+1)%md;
48     }
49     return q%md;
50 }
51 
52 int main()
53 {
54    // freopen("hanoi.in","r",stdin);
55    // freopen("hanoi.out","w",stdout);
56     a.m[0][0]=0; a.m[0][1]=2; a.m[0][2]=1;
57     a.m[1][0]=1; a.m[1][1]=2; a.m[1][2]=2;
58     a.m[2][0]=0; a.m[2][1]=0; a.m[2][2]=1;
59     while (~scanf("%d",&n)) {
60         matr b=qsm(a,n);
61         printf("%d
",b.m[0][2]%md);
62         printf("%d
",baoli(n));
63     }
64     return 0;
65 }