hdu 5411 CRB and Puzzle (矩阵高速幂优化dp)

#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;
const int mod = 2015;
int N,M;
struct Matrix
{
int M[55][55];
Matrix(){memset(M,0,sizeof(M));}
}U,P;

Matrix Add(const Matrix &a,const Matrix &b)
{
Matrix ret;
for(int i=1;i<=N;i++)
for(int j=1;j<=N;j++)
ret.M[i][j]=(a.M[i][j]+b.M[i][j])%mod;
return ret;
}

Matrix Multi(const Matrix &a,const Matrix &b)
{
Matrix ret;
for(int i=1;i<=N;i++)
{
for(int j=1;j<=N;j++)
{
for(int k=1;k<=N;k++)
ret.M[i][j]+=a.M[i][k]*b.M[k][j];
ret.M[i][j]%=mod;
}
}
return ret;
}
Matrix Pow(Matrix f,int n)  //f^n,U为单位矩阵
{
Matrix ret=U;
while(n)
{
if(n&1)
ret=Multi(ret,f);
n>>=1;
f=Multi(f,f);
}
return ret;
}

Matrix solve(int n) //等比数列求和
{
if(n==1)
return P;
Matrix temp=solve(n>>1);
if(n&1)
{
Matrix t=Pow(P,n/2+1);
return Add(Add(Multi(temp,t),temp),t);
}
else
return Add(temp,Multi(temp,Pow(P,n>>1)));
}

int main()
{
int ncase,i,j,k,x;
for(i=0;i<55;i++)
U.M[i][i]=1;
scanf("%d",&ncase);
while(ncase--)
{
scanf("%d%d",&N,&M);
memset(P.M,0,sizeof(P.M));
for(i=1;i<=N;i++)
{
scanf("%d",&k);
while(k--)
{
scanf("%d",&x);
P.M[i][x]=1;
}
}
if(M==1)
{
printf("%d\n",N+1);
continue ;
}
Matrix temp=solve(M-1);
int ans=N+1;
for(i=1;i<=N;i++)
for(j=1;j<=N;j++)
ans+=temp.M[i][j];
printf("%d\n",ans%mod);
}
return 0;
}