c++代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
#include <cstdio>
#include <iostream>
using namespace std;
#define mod 1000000007
const int MAX = 3;
struct Matrix{
        int  m[MAX][MAX];
}I;
void init (int n){//初始化单位矩阵
    for(int i=0 ; i<n ; i++){
        I.m[i][i]=1;
    }
}
Matrix matrixmul(Matrix a,Matrix b) //矩阵乘法
{
       int i,j,k;
       Matrix c;
       for (i = 0 ; i < MAX; i++)
           for (j = 0; j < MAX;j++)
             {
                 c.m[i][j] = 0;
                 for (k = 0; k < MAX; k++)
                     c.m[i][j] += (a.m[i][k] * b.m[k][j])%mod;
                 c.m[i][j] %= mod;
             }
       return c;
}
          
Matrix quickpow(Matrix m,long long n)
{
       Matrix b = I;
       while (n >= 1)
       {
             if (n & 1)
                b = matrixmul(b,m);
             n = n >> 1;
             m = matrixmul(m,m);
       }
       return b;
}
int main(){
    init(3);
    return 0;
}