2411

/*
状态压缩类 DP+ 计数
*/

// include file
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <cctype>
#include <ctime>

#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <bitset>

#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <set>
#include <list>
#include <functional>

using namespace std;

// typedef
typedef long long LL;
typedef unsigned long long ULL;

// 
#define read freopen("in.txt","r",stdin)
#define write freopen("out.txt","w",stdout)
#define FORi(a,b,c) for(int i=(a);i<(b);i+=c)
#define FORj(a,b,c) for(int j=(a);j<(b);j+=c)
#define FORk(a,b,c) for(int k=(a);k<(b);k+=c)
#define FORp(a,b,c) for(int p=(a);p<(b);p+=c)
#define FORii(a,b,c) for(int ii=(a);ii<(b);ii+=c)
#define FORjj(a,b,c) for(int jj=(a);jj<(b);jj+=c)
#define FORkk(a,b,c) for(int kk=(a);kk<(b);kk+=c)

#define FF(i,a)    for(int i=0;i<(a);i++)
#define FFD(i,a)   for(int i=(a)-1;i>=0;i--)

#define Z(a) (a<<1)
#define Y(a) (a>>1)

const double eps = 1e-6;
const double INFf = 1e10;
const int INFi = 1000000000;
const double Pi = acos(-1.0);

template<class T> inline T sqr(T a){return a*a;}
template<class T> inline T TMAX(T x,T y)
{
	if(x>y) return x;
	return y;
}
template<class T> inline T TMIN(T x,T y)
{
	if(x<y) return x;
	return y;
}
template<class T> inline void SWAP(T &x,T &y)
{
	T t = x;
	x = y;
	y = t;
}
template<class T> inline T MMAX(T x,T y,T z)
{
	return TMAX(TMAX(x,y),z);
}


// code begin
// 
//
int N,M;
#define MAXN 12

LL dp[MAXN][2050];
LL prerow[MAXN];
LL currow[MAXN];
int preten;
int curten;

void two2ten(LL A[],int &ans)
{
	ans = 0;
	FORi(0,M,1)
		ans = ans*2+A[i];
}

void ten2two(int t,LL A[])
{
	for(int i=M-1;i>=0;i--)
	{
		A[i] = t%2;
		t/=2;
	}
}

void dfs(int r,int c,int cs)
{
	if(c>=M)
	{
		dp[r][cs] += dp[r-1][preten];
		return;
	}

	
	if(prerow[c]==0 )
	{
		currow[c] = 1;
		cs += currow[c]*(1<<(M-1-c));
		dfs(r,c+1,cs);
		cs -= currow[c]*(1<<(M-1-c));
		currow[c] = 0;
	}
	

	if(prerow[c]==1)
	{
		dfs(r,c+1,cs);
	}

	if(c+1<M && prerow[c]==1 && prerow[c+1]==1 )
	{
		currow[c] = currow[c+1] = 1;
		cs += currow[c]*(1<<(M-1-c)) + currow[c+1]*(1<<(M-1-c-1));
		dfs(r,c+2,cs);
		cs -= currow[c]*(1<<(M-1-c)) + currow[c+1]*(1<<(M-1-c-1));
		currow[c] = currow[c+1] = 0;
	}
}

int main()
{
	read;
	write;
	while(scanf("%d %d",&N,&M)!=-1)
	{
		if(N+M==0) break;
		if((N*M)&1) 
		{
			printf("0\n");
			continue;
		}
		// 11就表示横着
		// 01就表示竖着
		// dp[i][j] = sigma(dp[i-1][k]), j和k可以并存
		memset(dp,0,sizeof(dp));
		dp[0][(1<<M)-1] = 1;
		FORi(1,N+1,1)
		{
			FORj(0,1<<M,1)
			{
				if( dp[i-1][j]==0 ) continue;
				
				ten2two(j,prerow);
				preten = j;

				memset(currow,0,sizeof(currow));
				dfs(i,0,0);
			}
		}

		printf("%lld\n",dp[N][(1<<M)-1]);
	}
	return 0;
}
posted @ 2011-04-06 20:08  AC2012  阅读(167)  评论(0编辑  收藏  举报