P1939 【模板】矩阵加速（数列）

3
6
8
10

4
9
19

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<iostream>
 4 using namespace std;
 5 const int MAXN=101;
 6 inline void read(int &n){char c='+';bool flag=0;n=0;    
 7 while(c<'0'||c>'9') c=='-'?flag=1,c=getchar():c=getchar();    
 8 while(c>='0'&&c<='9') n=n*10+c-48,c=getchar();flag==1?n=-n:n=n;}
 9 struct matrix
10 {
11     long long  m[11][11];
12     int h,l;matrix(){memset(m,0,sizeof(m));h=l=0;}
13 };
14 matrix ma;
15 int limit;
16 const int mod=1000000007;
17 matrix mul(matrix a,matrix b)
18 {
19     matrix c;c.h=c.l=3;
20     for(int k=0;k<a.l;k++)
21         for(int i=0;i<a.h;i++)
22             for(int j=0;j<b.l;j++)
23                 c.m[i][j]=(c.m[i][j]+(a.m[i][k]*b.m[k][j]))%mod;
24     return c;
25 }
26 matrix fast_martix_pow(matrix ma,int p)
27 {
28     matrix bg;
29     for(int i=0;i<3;i++)
30         for(int j=0;j<3;j++)
31             bg.m[i][j]=(i==j);
32     bg.h=bg.l=3;
33     while(p)
34     {
35         if(p&1)    bg=mul(bg,ma);
36         ma=mul(ma,ma);
37         p>>=1;
38     }
39     return bg;
40 }
41 int main()
42 {
43     int T;read(T);
44     while(T--)
45     {
46         int m;
47         read(m);
48         if (m<=3&&m>0) {cout<<1<<endl; continue;} else if (m<=0) {cout<<0<<endl; continue;} 
49         matrix a,b;
50         a.m[0][0]=1;
51         a.m[0][2]=1;
52         a.m[1][0]=1;
53         a.m[2][1]=1;
54         b.m[0][0]=1;
55         b.m[1][0]=1;
56         b.m[2][0]=1;
57         a.h=a.l=3;
58         b.h=3;b.l=1;
59         a=fast_martix_pow(a,m-3);
60         a=mul(a,b);
61         printf("%d\n",a.m[0][0]%mod);
62     }
63     return 0;
64 }