1 #include<stdio.h>
2 #include<string.h>
3 long long result[15][15],dp[15][2050];
4 int n,m,t;
5 long long dfs(int l,int state)
6 {
7 int i,j,judge,flag,last;
8 long long sum;
9 if (dp[l][state]!=-1) return dp[l][state];
10 if (l==1)
11 {
12 for (j=0;j<m;j++) if ((state&(1<<(j)))==0) {dp[1][state]=0; return 0; }
13 dp[1][state]=1; return 1;
14 }
15 last=state^((1<<m)-1); sum=0;
16 for (i=0;i<(1<<m);i++)
17 {
18 flag=1;
19 for (j=0;j<m;j++)
20 if (((last&(1<<j))!=0)&&((i&(1<<j))==0)) flag=0;
21 if (flag==0) continue;
22 judge=last^i;
23 for (j=0;j<m;j++)
24 {
25 if ((judge&(1<<j))!=0)
26 {
27 if (j==m-1||((judge&(1<<(j+1)))==0)) {flag=0; break;}
28 j++;
29 }
30 }
31 if (flag==1) sum+=dfs(l-1,i);
32 }
33 dp[l][state]=sum;
34 return dp[l][state];
35 }
36 int main()
37 {
38 memset(result,0,sizeof(result));
39 while (~scanf("%d%d",&n,&m)&&(n+m))
40 if ((n*m)%2) printf("0\n"); else
41 {
42 if (n>m) { t=n; n=m; m=t; }
43 if (result[n][m]) printf("%I64d\n",result[n][m]); else
44 {
45 memset(dp,-1,sizeof(dp));
46 result[n][m]=dfs(n+1,(1<<m)-1);
47 printf("%I64d\n",result[n][m]);
48 }
49 }
50 }
http://acm.hdu.edu.cn/showproblem.php?pid=1400
