hdu 1575 求一个矩阵的k次幂 再求迹 （矩阵快速幂模板题）

 1 # include <iostream>
 2 # include <cstdio>
 3 # include <algorithm>
 4 # include <map>
 5 # include <cmath>
 6 # define LL long long
 7 using namespace std ;
 8 
 9 const int MAX = 12 ;
10 const int MOD = 9973 ;
11 int n ; //n*n 矩阵
12 
13 struct Matrix
14 {
15     int mat[MAX][MAX];
16 };
17 Matrix mul(Matrix a,Matrix b) //矩阵乘法
18 {
19     Matrix c;
20     for(int i=0;i<n;i++)
21         for(int j=0;j<n;j++)
22         {
23             c.mat[i][j]=0;
24             for(int k=0;k<n;k++)
25             {
26                 c.mat[i][j]=(c.mat[i][j] + a.mat[i][k]*b.mat[k][j])%MOD;
27             }
28         }
29     return c;
30 }
31 Matrix pow_M(Matrix a,int k)  //矩阵快速幂
32 {
33     Matrix ans;
34     memset(ans.mat,0,sizeof(ans.mat));
35     for (int i=0;i<n;i++)
36         ans.mat[i][i]=1;
37     Matrix temp=a;
38     while(k)
39     {
40         if(k&1)ans=mul(ans,temp);
41         temp=mul(temp,temp);
42         k>>=1;
43     }
44     return ans;
45 }
46 int main ()
47 {
48     //freopen("in.txt","r",stdin) ;
49     int T ;
50     scanf("%d" , &T) ;
51     while(T--)
52     {
53         int k ;
54         Matrix s ;
55         Matrix ans ;
56         scanf("%d %d" , &n , &k) ;
57         for (int i = 0 ; i < n ; i++)
58             for (int j = 0 ; j < n ; j++)
59                 scanf("%d" , &s.mat[i][j]) ;
60         ans = pow_M(s,k) ;
61         int sum = 0 ;
62         for (int i = 0 ; i < n ; i++)
63             sum= (sum + ans.mat[i][i]) % MOD ;
64         printf("%d\n" , sum) ;
65 
66     }
67 
68     return 0 ;
69 }