HDU 4064 Carcassonne

 1 #include<bits/stdc++.h>
 2 #define mod 1000000007
 3 using namespace std;
 4 const int N=15,S=531441;
 5 int ca,t,n,m,cur,mul,base[13],g[N][N][4];
 6 long long ans,f[2][S];
 7 char s[5];
 8 int change(char x){
 9     return x==‘C‘?0:(x==‘R‘?1:2);
10 }
11 void dfs(int c,int num,int up,int down,int right)
12 {
13     if (num>m)
14     {
15         if (c==1) f[cur][down]=(f[cur][down]+mul)%mod;
16         else f[cur][down]=(f[cur][down]+f[cur^1][up]*mul)%mod;
17         return;
18     }
19     if (g[c][num][0]==g[c][num][1]&&g[c][num][1]==g[c][num][2]&&g[c][num][2]==g[c][num][3])
20     {
21         int add=g[c][num][0]; mul*=4;
22         if (right==-1||right==add) dfs(c,num+1,up*3+add,down*3+add,add);
23         mul/=4; return;
24     }
25     for (int i=0;i<4;++i)
26     {
27         int U=g[c][num][i];
28         int R=g[c][num][(i+1)%4];
29         int D=g[c][num][(i+2)%4];
30         int L=g[c][num][(i+3)%4];
31         if (right==-1||right==L) dfs(c,num+1,up*3+U,down*3+D,R);
32     }
33 }
34 int main()
35 {
36     scanf("%d",&t); base[0]=1;
37     for (int i=1;i<=12;++i)
38     base[i]=base[i-1]*3;
39     while (t--)
40     {
41         scanf("%d%d",&n,&m);
42         for (int i=1;i<=n;++i)
43         for (int j=1;j<=m;++j)
44         {
45             scanf("%s",s);
46             for (int k=0;k<4;++k)
47             g[i][j][k]=change(s[k]);
48         }
49         memset(f,0,sizeof(f));
50         cur=ans=0;
51         for (int i=1;i<=n;++i)
52         {
53             cur^=1; mul=1;
54             dfs(i,1,0,0,-1);
55             for (int j=0;j<base[m];++j)
56             f[cur^1][j]=0;
57         }
58         for (int i=0;i<base[m];++i)
59         ans=(ans+f[cur][i])%mod;
60         printf("Case %d: %d\n",++ca,ans);
61     }
62     return 0;
63 }