Yokohama.rb で 2014年10月に出した問題の実装例

rotcell_yokohamarb.rb

# problem : http://nabetani.sakura.ne.jp/yokohamarb/2014.10.rotcell/

NEIBOURS = [[-1, -1], [-1, 0], [-1, 1], [0, 1], [1, 1], [1, 0], [1, -1], [0, -1]]
BOARD_SIZE = 5

def pos_to_index(s)
  s[0]+s[1]*BOARD_SIZE
end

def process( board, cmd )
  y,x = board.index( cmd.downcase ).divmod(BOARD_SIZE)
  move_pos = NEIBOURS
    .map{ |s| [s[0]+x, s[1]+y] }
    .select{ |s| s.all?{ |xy| (0...BOARD_SIZE)===xy } }
  move_names = move_pos.map{ |s| board[pos_to_index(s)] }
  move_names
    .rotate(cmd==cmd.upcase ? -1 : 1)
    .zip(move_pos)
    .each{ |name,s| board[pos_to_index(s)] =name }
  move_names.sort.join
end

def solve( src )
  board = [*?a..?y]
  src.chars.inject(nil) do |_,cmd|
    process( board, cmd )
  end
end

DATA.map do |line|
  id,src,expected = line.split(/\s+/)
  actual = solve( src )
  ok = actual==expected
  puts [(ok ? "ok" : "***NG***"), id, src, actual, expected ].join(" ")
  ok
end.all?.tap{ |ok|
  puts( ok ? "ok" : "***NG***" )
}

__END__
0 YokoHamarb  acdfp 
1 Ruby  twx 
2 ruby  nst 
3 PHP gkluv 
4 a bfg 
5 b acfgh 
6 m ghilnqrs  
7 mg  bcdhilmq  
8 Mg  fhiklmpq  
9 MS  ijmnoqrt  
10  mG  bcdhilmq  
11  lf  abcghklp  
12  paq lprvw 
13  bFH abcfg 
14  Agh abcfgklm  
15  Msul  pruvw 
16  RSRX  jorty 
17  xTsn  ijmos 
18  FHwnQ lmorsvwx  
19  jIDIb cfghilmo  
20  rLGPq ilmnprvx  
21  WRiFhd  ceg 
22  gkfLfh  cfglmpqr  
23  STydYQ  hklmpruv  
24  spaeAWJ cdehimns  
25  xTxTXwY mwx 
26  xyQMkMi cdejlnow  
27  HJkxpWxA  cdhkp 
28  hgaGDodg  djo 
29  abKBmkBc  bdfik 
30  mCvlhnilm adfgikqr  
31  StyxTYsIh imnostxy  
32  HLHnhLMLC ahlmn 
33  DuHmbFQysI  ehj 
34  cGfGCaLgCq  acguv 
35  OisYOrOXwq  ilnstvwx  
36  wMnYIukHAvO bdefhjmn  
37  HCfBhKHkhDF abdghikn  
38  pUPmwrHsYSH morsy 
39  PnCYYWnPoUxq  bfopv 
40  DiojiYXowowr  cilmnstw  
41  HLNsiNMnbAnn  abdkm