矩阵快速幂（构造）

题目：https://ac.nowcoder.com/acm/contest/221/C

构造矩阵

#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;
const int INF=0x3f3f3f3f;
const int maxn=10;
const int mod=1e9+7;
typedef long long LL;
LL n;
typedef struct node
{
   LL z[maxn][maxn];
}matrix;
matrix matrix_mul(matrix a,matrix b)
{
   matrix c;
   memset(c.z,0,sizeof(c.z));

   for(int i=1;i<=6;i++)
   {
      for(int j=1;j<=6;j++)
      {
         for(int u=1;u<=6;u++)
         {
            c.z[i][j]+=(a.z[i][u]%mod)*(b.z[u][j]%mod)%mod;
         }
      }
   }
   return c;
}
matrix matrix_pow(matrix a,int n)
{
   matrix ans;
   memset(ans.z,0,sizeof(ans.z));
   for(int i=1;i<=6;i++)
   {
      ans.z[i][i]=1;
   }
   while(n>0)
   {
      if(n&1)
         ans=matrix_mul(ans,a);
      n>>=1;
      a=matrix_mul(a,a);

   }
   return ans;
}
int main()
{
   while(cin>>n)
   {
      if(n==0)
         break;
      matrix t;
      memset(t.z,0,sizeof(t.z));
      t.z[1][1]=1;t.z[1][2]=1;t.z[1][3]=0;t.z[1][4]=1;t.z[1][5]=0;t.z[1][6]=0;
      t.z[2][1]=0;t.z[2][2]=2;t.z[2][3]=3;t.z[2][4]=0;t.z[2][5]=1;t.z[2][6]=1;
      t.z[3][1]=0;t.z[3][2]=1;t.z[3][3]=0;t.z[3][4]=0;t.z[3][5]=0;t.z[3][6]=0;

      t.z[4][1]=0;t.z[4][2]=0;t.z[4][3]=0;t.z[4][4]=1;t.z[4][5]=2;t.z[4][6]=1;
      t.z[5][1]=0;t.z[5][2]=0;t.z[5][3]=0;t.z[5][4]=0;t.z[5][5]=1;t.z[5][6]=1;
      t.z[6][1]=0;t.z[6][2]=0;t.z[6][3]=0;t.z[6][4]=0;t.z[6][5]=0;t.z[6][6]=1;

      matrix y;
      y.z[1][1]=2;
      y.z[2][1]=2;
      y.z[3][1]=1;
      y.z[4][1]=4;
      y.z[5][1]=2;
      y.z[6][1]=1;
      matrix zz=matrix_pow(t,n-1);
      LL res=0;
     // for(int i=1;i<=6;i++)
       //  cout << ans.z[1][i] << ' ' ;
      //cout << endl;
      for(int i=1;i<=6;i++)
      {
         res+=zz.z[1][i]*y.z[i][1];
         res%=mod;
      }
      cout  << res << endl;

   }
   return 0;
}