$sudoku = []
$color = []

$sectors = [[0,0], [1,0], [2,0], [0,1], [1,1], [2,1], [0,2], [1,2], [2,2]]
def colgroup(x)
  [[x,0],[x,1],[x,2],[x,3],[x,4],[x,5],[x,6],[x,7],[x,8]]
end
def rowgroup(y)
  [[0,y],[1,y],[2,y],[3,y],[4,y],[5,y],[6,y],[7,y],[8,y]]
end
def secgroup(id)
  x = 3 * (id % 3)
  y = 3 * (id / 3)
  $sectors.map { |n| [n[0]+x, n[1]+y] }
end
def sec_id(x,y)
  $sectors.index([x / 3, y / 3])
end

def sdump(sid)
  9.times { |y| p $sudoku[sid][y] }
end

def sprint(sid)
  9.times do |y|
    9.times { |x| print(sget(sid,x,y).is_a?(Numeric) ? sget(sid,x,y).to_s : " ") }
    print "\n"
  end
end

def sget(sid,x,y)
  $sudoku[sid][y][x]
end

def find_numbers(sid,positions)
  positions.map{ |p| sget(sid,p[0],p[1]) }.uniq
end

def find_possibilities(sid, positions, num)
  return [] if positions.find{ |p| x = sget(sid,p[0],p[1]); x == num }
  positions.find_all{ |p| x = sget(sid,p[0],p[1]); x.is_a? Array and x.include? num }
end

def recalculate(sid)
  9.times do |x| 9.times do |y|
    $sudoku[sid][y][x] = [1,2,3,4,5,6,7,8,9] if !$sudoku[sid][y][x].is_a? Numeric
  end end
  9.times do |y| 9.times do |x|
    if !$sudoku[sid][y][x].is_a? Numeric
      related = secgroup(sec_id(x,y)) + colgroup(x) + rowgroup(y)
      $sudoku[sid][y][x] = $sudoku[sid][y][x] - find_numbers(sid,related)
    end
    if $sudoku[sid][y][x].is_a? Array and $sudoku[sid][y][x].length == 1
      puts "#{x} #{y} #{$sudoku[sid][y][x][0]}"
      $sudoku[sid][y][x] = $sudoku[sid][y][x][0]
    end
  end end
end

def sset(sid,x,y,num)
  puts "#{x} #{y} #{num}" if num.is_a? Numeric or num.length < 9
  num = num[0] if !num.is_a? Numeric and num.length == 1 
  if num.is_a? Numeric and !$sudoku[sid][y][x].is_a? Numeric and !$sudoku[sid][y][x].include?(num)
    puts "WARNING: sset called with invalid num #{num}"
    return
  end
  $sudoku[sid][y][x] = num
  if $color[sid][y][x]
    $sudoku.length.times do |zsid| 9.times do |zx| 9.times do |zy|
      if $color[sid][y][x] == $color[zsid][zy][zx]
        puts "#{zsid}: #{zx} #{zy} #{num}" if num.is_a? Numeric
        $sudoku[zsid][zy][zx] = (num.is_a?(Numeric) ? num : num & $sudoku[zsid][zy][zx])
      end
    end end end
  end
end

$pass_count = 0

def pass(sid)
  $pass_count = $pass_count + 1
  puts "===== PASS #{$pass_count}, SUDOKU #{sid} ====="
  
  9.times do |num| 9.times do |gid|
    # check rows for unique numbers
    group = rowgroup(gid)
    choices = find_possibilities(sid, group, num)
    sset(sid, choices[0][0], choices[0][1], num) if choices.length == 1
    
    # check columns for unique numbers
    group = colgroup(gid)
    choices = find_possibilities(sid, group, num)
    sset(sid, choices[0][0], choices[0][1], num) if choices.length == 1
    
    # check sectors for unique numbers
    group = secgroup(gid)
    choices = find_possibilities(sid, group, num)
    sset(sid, choices[0][0], choices[0][1], num) if choices.length == 1
  end end
  
  recalculate sid
end

def pass_all
  $sudoku.length.times { |i| pass i }
end

def create_new
  Array.new(9).map{Array.new(9).map{[1,2,3,4,5,6,7,8,9]}}
end

def empty_color
  Array.new(9).map{Array.new(9)}
end

def load(file)
  sid = $sudoku.length
  puts "LOADING SUDOKU #{sid}"
  $sudoku << create_new
  $color << empty_color
  
  file.gets # separator
  9.times do |y|
    line = file.gets.chomp
    9.times do |x|
      policko = line[2*x,1]
      $color[sid][y][x] = policko if policko != " "
      policko = line[2*x+1,1]
      if policko != " " and policko.to_i == 0
        puts "ERROR: invalid input syntax at char #{2*x+2} line #{y+1} of sudoku #{sid+1}"
        exit
      end
      $sudoku[sid][y][x] = policko.to_i if policko != " "
    end
  end
  
  recalculate sid
end

def loadf(filename = "sudoku1.txt")
  File.open(filename) do |f|
    f.gets.to_i.times { load f }
  end
end