BJFU 1440 fudq的ACM

矩阵快速幂

 #include<cstdio>
 #include<algorithm>
 using namespace std;
 const int Nmax = ;
 const int INF =1e9;
 const int mod=;

 long long n;
 int error;
 struct Matrix
 {
     int n,m;
     long long map[Nmax][Nmax];
     Matrix(int x,int y)
     {
         n=x;m=y;
         for(int i=;i<=n;i++)
             for(int j=;j<=m;j++)
                 map[i][j]=;
     }
     Matrix operator * (const Matrix b)
     {
         Matrix c(n,b.m);
         if(m==b.n)
         {
             for(int i=;i<=c.n;i++)
                 for(int j=;j<=c.m;j++)
                     for(int k=;k<=m;k++)
                         c.map[i][j]=(c.map[i][j]+(map[i][k]*b.map[k][j])%mod)%mod;
             return c;
         }
         printf("error!!!!!!!!!!!!!!\n");
     }
 };

 Matrix get(long long n)
 {
     Matrix base(,);
     base.map[][]=;
     base.map[][]=;
     base.map[][]=;
     base.map[][]=;
     Matrix ans(,);
     ans.map[][]=;
     ans.map[][]=;
     ans.map[][]=;
     ans.map[][]=;

     while(n>)
     {
         if(n & )
             ans=ans*base;
         base=base*base;
         n>>=;
     }

     return ans;
 }

 int main()
 {
     //freopen("bjfu.in","r",stdin);
     Matrix base(,);
     base.map[][]=;
     base.map[][]=;

     while(scanf("%I64d",&n)==)
     {
         if(n>=)
         {
             Matrix ans=get(n-);
             ans=ans*base;
             printf("%I64d\n",ans.map[][]);
         }
         else
         {
             printf("%I64d\n",base.map[-n][]);
         }
     }
     return ;
 }