矩阵快速幂 模板与简单讲解

 1 void solve(matrix t,long long o)
 2 {
 3     matrix e;
 4 
 5     memset(e.a,0,sizeof(e.a));
 6 
 7     for (int i = 0;i < d;i++)
 8         e.a[i][i] = 1;
 9 
10     while (o)
11     {
12         if (o & 1)
13         {
14             e = mul(e,t);
15         }
16 
17         o >>= 1;
18 
19         t = mul(t,t);
20     }
21 
22     long long res = 0;
23 
24     for (int i = 0;i < d;i++)
25         res = (res + e.a[0][i] * f[d-i-1]) % m;
26 
27     printf("%lld\n",res);
28 }

 1 struct matrix
 2 {
 3     long long a[20][20];
 4 };
 5 
 6 matrix mul(matrix x,matrix y)
 7 {
 8     matrix c;
 9 
10     for (int i = 0;i < d;i++)
11         for (int j = 0;j < d;j++)
12     {
13         c.a[i][j] = 0;
14 
15         for (int k = 0;k < d;k++)
16         {
17             c.a[i][j] = (c.a[i][j] + x.a[i][k] * y.a[k][j] % m) % m;
18         }
19     }
20 
21     return c;
22 }