HDU 1575(裸矩阵快速幂)

emmmmm..就是矩阵快速幂，直接附代码：

 #include <cstdio>
 using namespace std;
 const int maxn = ;
 const int mod = ;
 struct Matrix
 {
     int m[maxn][maxn];
 }ans,res;
 int n;
 Matrix mul(Matrix a,Matrix b)
 {
     Matrix tmp;
     for(int i = ; i <= n; i++)
         for(int j = ; j <= n; j++)
             tmp.m[i][j] = ;
     for(int i = ; i <= n; i++)
         for(int j = ; j <= n; j++)
             for(int k = ; k <= n; k++)
                 tmp.m[i][j] += ((a.m[i][k] % mod)*(b.m[k][j] % mod))%mod;
     return tmp;
 }

 void quickpow(int N)
 {
     for(int i = ; i <= n; i++)
         for(int j = ; j <= n; j++)
             if(i == j)  ans.m[i][j] = ;
             else ans.m[i][j] = ;
     while(N)
     {
         if(N&) ans = mul(ans,res);
         res = mul(res,res);
         N = N >>;
     }
 }

 int main()
 {
     int t,k,wu;
     scanf("%d",&t);
     while(t--)
     {
         scanf("%d%d",&n,&k);
         wu = ;
         for(int i = ; i <= n; i++)
             for(int j = ; j <= n; j++)
                 scanf("%d",&res.m[i][j]);
         quickpow(k);
         for(int i = ; i <= n; i++)
             for(int j = ; j <= n; j++)
                 if(i == j)  wu += ans.m[i][j];
         printf("%d\n",wu%mod);
     }
     return ;
 }