# Quiz 105 Solution - now with Trees!

Its not quite as clean as I’d like but there are other things I should
be
doing…

class Tournament

def initialize players
raise “Must be more than one player in the tournament!” if players <
2
@players = players
@list = Array.new(players) { |i| i+1 }

``````# Add 'bye's up to the next power of 2
next_power = 2 ** sprintf("%b",players).length
unless players == next_power / 2
(players+1).upto(next_power) { @list << 'bye' }
end
@list = generate @list
``````

end

def generate list
len = list.length
return list if len <= 2
left = list[0…(len/4-1)]+list[-(len/4)…-1]
right= list[(len/4)…-(len/4+1)]
[generate(left),generate(right)]
end

def to_s
lines = []
depth = sprintf("%b",@list.flatten.length).length - 1
title = “”
1.upto(depth) { |r| title += sprintf( “R%d “, r ) }
lines << title
lines << (”=” * title.length)
lines << to_a(@list)
lines.join("\n")
end

# recursively build the tree display

def to_a list = @list
lines = []
return lines if list.length < 2
if list[0].is_a? Array
left = to_a(list[0]).flatten
right = to_a(list[1]).flatten
indent = (left + right).collect { |i| i.length }.max
all = left[0…(left.length / 2)]
left[(left.length / 2 + 1)…-1].each do |i|
all << ((i + (" “*indent))[0…(indent-1)] + “|”)
end
all << (” “*indent) + “|—”
right[0…(right.length / 2 - 1)].each do |i|
all << ((i + (” “*indent))[0…(indent-1)] + “|”)
end
all << right[(right.length / 2)…-1]
else
return [list[0].to_s, “—”, " |—”, “—”, list[1].to_s]
end
end
end