Dancing Links～～～
题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=2518
Dominoes
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 31 Accepted Submission(s): 8
Some day, Tom's father buys him a box of dominoes blocks. In the box, there are 12 different blocks, which are shown above. Tom is a boy who likes to do practice in intelligence, so he spends a whole afternoon in finishing two different rectangles with 3 * 20, which are shown below.
①⑤⑤⑤⑤⑨⑩⑩⑩⑥⑥⑧②②②②②③④④
①⑤⑿⑿⑨⑨⑨⑩⑥⑥⑦⑧⑧⑧⑾⑾③③③④
①①①⑿⑿⑿⑨⑩⑥⑦⑦⑦⑦⑧⑾⑾⑾③④④
①⑧⑦⑦⑦⑦⑥⑩⑨⑿⑿⑿②②②②②③④④
①⑧⑧⑧⑦⑥⑥⑩⑨⑨⑨⑿⑿⑤⑾⑾③③③④
①①①⑧⑥⑥⑩⑩⑩⑨⑤⑤⑤⑤⑾⑾⑾③④④
Tom is sure that these are the only solutions for 3 * 20, and he wants to know the number of solutions for 4 * 15, 5 * 12, ... Can you help him?
You should notice that if a solution will be the same as the other by some flip or rotate, these two solutions should be consider as the same.
好些天之前写的题了，思路比较简单，不过代码量比较大。。
需要判断出每个图形有几种旋转方式。 建立矩阵，列数数72，60个小方格，外加12个图形限制，每个图形只能用一次。。
因为只有6中情况，所以要先用自己的代码跑出每组例子，然后直接输出结果就ok了。
若是直接把代码提交上去而不进行这样猥琐的处理，估计没有不超时的~~
此题不贴代码了，因为总共就8人过，，保留一些悬念比较好。 ^_^。。
贴一下我总结的旋转规律：
int map1[4][5][2]={0,0,1,0,2,0,2,1,2,2, 0,0,0,1,0,2,1,0,2,0, 0,0,0,1,0,2,1,2,2,2, 0,2,1,2,2,2,2,1,2,0};
int map4[4][5][2]={0,-1,0,1,1,-1,1,0,1,1 , -1,0,1,0,-1,1,0,1,1,1, 0,-1,0,1,-1,-1,-1,0,-1,1, -1,0,1,0,-1,-1,0,-1,1,-1};
int map5[8][5][2]={0,0,1,0,1,1,1,2,1,3 ,0,0,0,1,-1,1,-2,1,-3,1 ,0,0,-1,0,-1,-1,-1,-2,-1,-3, 0,0,0,-1,1,-1,2,-1,3,-1
,0,0,1,0,1,-1,1,-2,1,-3, 0,0,0,-1,-1,-1,-2,-1,-3,-1, 0,0,-1,0,-1,1,-1,2,-1,3, 0,0,0,1,1,1,2,1,3,1};//
int map6[4][5][2]={0,0,1,0,1,1,2,1,2,2, 0,2,1,2,1,1,2,0,2,1, 0,0,0,1,1,1,1,2,2,2, 0,1,0,2,1,0,1,1,2,0};
int map7[8][5][2]={0,0,1,-1,1,0,1,1,1,2, 0,0,0,1,1,1,-1,1,-2,1, 0,0,-1,0,-1,1,-1,-1,-1,-2, 0,0,-1,-1,0,-1,1,-1,2,-1,
0,0,1,0,1,1,1,-1,1,-2, 0,0,0,-1,1,-1,-1,-1,-2,-1, 0,0,-1,-1,-1,0,-1,1,-1,2, 0,0,-1,1,0,1,1,1,2,1};
int map8[4][5][2]={0,2,1,2,1,1,1,0,2,0, 0,0,0,1,1,1,2,1,2,2, 0,0,1,0,1,1,1,2,2,2, 0,1,0,2,1,1,2,1,2,0};
int map9[8][5][2]={0,0,0,-1,-1,0,-1,1,-2,0, 0,0,0,1,-1,0,-2,0,-1,-1, 0,0,-1,0,0,1,0,2,1,1, 0,0,1,0,0,1,0,2,-1,1,
0,0,0,-1,1,0,2,0,1,1, 0,0,0,1,1,0,2,0,1,-1, 0,0,1,0,0,-1,0,-2,-1,-1, 0,0,-1,0,0,-1,0,-2,1,-1};
int map10[4][5][2]={0,0,0,-1,0,1,-1,0,-2,0, 0,0,-1,0,1,0,0,1,0,2, 0,0,0,-1,0,1,1,0,2,0, 0,0,-1,0,1,0,0,-1,0,-2};
int map11[8][5][2]={0,0,0,1,1,-1,1,0,1,1, 0,0,0,-1,1,-1,1,0,1,1, 0,0,-1,0,-1,1,0,1,1,1, 0,0,1,0,1,1,0,1,-1,1,
0,0,0,1,-1,-1,-1,0,-1,1, 0,0,0,-1,-1,-1,-1,0,-1,1, 0,0,-1,0,-1,-1,0,-1,1,-1, 0,0,1,0,-1,-1,0,-1,1,-1};
int map12[8][5][2]={0,0,1,0,1,-1,0,1,0,2, 0,0,1,0,1,1,0,-1,0,-2, 0,0,0,1,1,1,-1,0,-2,0, 0,0,0,1,-1,1,1,0,2,0,
0,0,-1,0,-1,-1,0,1,0,2, 0,0,-1,0,-1,1,0,-1,0,-2, 0,0,0,-1,1,-1,-1,0,-2,0, 0,0,0,-1,-1,-1,1,0,2,0};
很黄很暴力吧！！ 当时提交成功的时候我都很佩服我自己，这么多数竟然没写错一个。。。。
