babysfirstgolf.rb

# http://codegolf.stackexchange.com/questions/64650/generate-toothpick-sequence

n = ARGV[0].to_i

$t = (n * 2).times.map { [' '] * n * 2}

def add_backslash_top (n,m,c)
  if $t[n] && $t[n][m] == " " && c!=0
    $t[n][m] = '\\'
    add_slash_left(n,m-1,c-1)
    add_slash_right(n-1,m,c-1)
  end
end

def add_backslash_bottom (n,m,c)
  if $t[n] && $t[n][m] == " " && c!=0
    $t[n][m] = '\\'
    add_slash_right(n,m+1,c-1)
    add_slash_left(n+1,m,c-1)
  end
end

def add_slash_left (n,m,c)
  if $t[n] && $t[n][m] == " " && c!=0
    $t[n][m] = '/'
    add_backslash_top(n,m-1,c-1)
    add_backslash_bottom(n+1,m,c-1)
  end
end

def add_slash_right (n,m,c)
  if $t[n] && $t[n][m] == " " && c!=0
    $t[n][m] = '/'
    add_backslash_top(n-1,m,c-1)
    add_backslash_bottom(n,m+1,c-1)
  end
end

add_backslash_top(n-1,n-1,n)
add_backslash_bottom(n,n,n)

p $t
puts $t.map { |e| e.join }