オフラインリアルタイムどう書くE18の問題をRubyで解く

問題はこちら
http://nabetani.sakura.ne.jp/hena/orde18twintri/
処理遅いです。

def make_tri(pat)
  pat =~ /(\d+),(\d+)([RLTB])(\d+)/
  x = $1.to_i
  y = $2.to_i
  dx,dy = {'R'=>[-1,0],'L'=>[1,0],'T'=>[0,1],'B'=>[0,-1]}[$3]
  h = $4.to_i
  tri = [[[x,y]]]
  (h-1).times{|i|
    w = tri[-1].clone
    if dy == 0
      w.unshift([w[0][0],w[0][1]-1])
      w.push([w[-1][0],w[-1][1]+1])
    else
      w.unshift([w[0][0]-1,w[0][1]])
      w.push([w[-1][0]+1,w[-1][1]])
    end
    tri << w.map{|x,y| [x+dx,y+dy]}
  }
  tri.flatten(1)
end

def solve(q)
  a,b = q.split('/')
  a_t = make_tri(a)
  b_t = make_tri(b)
  (a_t&b_t).size
end

DATA.readlines.each do |line|
  no,q,a = line.strip.split(/\s+/)
  ans = solve(q)
  print no + "\t" + ans.to_s
  puts ans == a.to_i ? ' o' : ' x'
end
__END__
0   7,0R6/3,1B5 15  
1   1,6L4/4,9R9 4   
2   0,2R4/1,3B4 3   
3   1,2L4/1,2L5 16  
4   3,2L5/5,6B4 8   
5   4,1B3/6,3B4 4   
6   4,4R7/4,3R5 20  
7   4,5R9/0,7T3 7   
8   4,7T9/1,6T3 1   
9   4,8B7/3,7L4 10  
10  5,3L3/9,8L4 0   
11  5,6B4/4,4R2 3   
12  5,6B4/8,5R4 8   
13  5,8B9/5,2L2 4   
14  6,1L5/7,1T2 3   
15  7,2B4/7,2T4 1   
16  7,3T9/9,6L6 11  
17  8,0R6/8,1R7 30  
18  0,4R7/4,6R10    36  
19  10,4L4/9,1T6    9   
20  2,2T7/6,7T10    4   
21  2,7R4/1,6L8 2   
22  3,0R10/1,2T7    7   
23  3,5T2/3,6B10    2   
24  4,7R10/8,2T8    6   
25  6,8B10/4,5B6    36  
26  9,2B7/1,1B10    6   
27  9,3R14/2,4R1    1   
28  3,0R10/0,6B10   54  
29  4,10T8/4,10T8   64  
30  1,5T10/1,20B10  56  
31  15,16L4/5,12L12 4   
32  12,11T18/7,18R18    34  
33  15,16T14/5,12L15    44  
34  5,10L40/22,22B10    100 
35  46,34T34/34,29T14   30  
36  52,75L12/88,69T54   0   
37  67,83B70/99,48T14   52  
38  291,11T120/258,54B130   424 
39  62,170L139/133,172R21   441 
40  98,189B116/183,127R27   240 
41  646,684B96/435,690R772  0   
42  113,668L866/581,859L852 158404  
43  309,321B162/137,420B423 15750   
44  5474,6459R9089/8177,150R5120    376996  
45  2399,1640B2451/1718,2100L1623   221334  
46  5621,8460T7612/2715,5697L8851   861192