hdu1693 插头dp

题意:给了一个矩阵图，要求使用回路把图中的树全部吃掉的方案树，没有树的点不能走，吃完了这个点也就没有了，走到哪吃到哪

用插头dp搞

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <vector>
#include <string.h>
using namespace std;
typedef long long LL;
int G[][];
int nrows,ncols;
struct State
{
    int up[];
    int left;
    int encode()const
    {
        int key=left;
        for(int i=; i<ncols; i++)key=key*+up[i];
        return key;
    }
    bool next(int row,int col, int U, int D, int L, int R,State &T)const
    {
        if(row==nrows- && D!= )return false;
        if(col==ncols- && R!= )return false;
        int must_left = (col>&&left!=);
        int must_up = (row> && up[col]!=);
        if( ( must_left!= && L==) || (must_left== && L!=) )return false ;
        if( ( must_up != && U== ) || (must_up == && U!= )) return false;
        for(int i=; i<ncols; i++)T.up[i]=up[i];
        T.up[col]=D;
        T.left=R;
        return true;
    }
};
LL memo[][][<<];
LL rec(int row,int col,const State &S)
{
    if(col == ncols ){ col=; row++ ;}
    if(row == nrows) return ;
    int key=S.encode();
    LL &res=memo[row][col][key];
    if(res>=)return res;
    res=;
    State T;
    if(G[row][col])
    {
       if(S.next(row,col,,,,,T))
        res+=rec(row,col+,T);
       if(S.next(row,col,,,,,T))
        res+=rec(row,col+,T);
       if(S.next(row,col,,,,,T))
        res+=rec(row,col+,T);
       if(S.next(row,col,,,,,T))
        res+=rec(row,col+,T);
       if(S.next(row,col,,,,,T))
        res+=rec(row,col+,T);
       if(S.next(row,col,,,,,T))
        res+=rec(row,col+,T);
    }else
    {
        if(S.next(row,col,,,,,T))
         res+=rec(row,col+,T);
    }
    return res;
}
int main()
{
    int cas;
    scanf("%d",&cas);
    for(int cc=; cc<=cas; cc++)
    {
        scanf("%d%d",&nrows,&ncols);
        for(int i=; i<nrows; i++)
            for(int j=; j<ncols ;j++)
            scanf("%d",&G[i][j]);
        State S;
        memset(&S,,sizeof(S));
        memset(memo,-,sizeof(memo));
        LL ans=rec(,,S);
        printf("Case %d: There are %I64d ways to eat the trees.\n",cc,ans);
    }
    return ;
}