矩阵快速幂模板

 1 struct Matrix {
 2         int n , m ;
 3         int mat[M][M] ;
 4         int * operator [] (int x) {
 5                 return mat[x] ;
 6         }
 7 }
 8 
 9 Matrix mul (Matrix x , Matrix y) {
10         Matrix res ;
11         memset (res.mat , 0 , sizeof(res.mat)) ;
12         res.n = x.n , res.m = y.m ;
13         for (int i = 0 ; i < x.n ; i ++) {
14                 for (int j = 0 ; j < y.m ; j ++) {
15                         for (int k = 0 ; k < x.m ; k ++) {
16                                 ll tmp = x[i][k] * y[k][j] ;
17                                 res[i][j] += tmp ;
18                         }
19                 }
20         }
21         return res ;
22 }