Created
January 20, 2010 23:01
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# The Computer Language Shootout Benchmarks | |
# http://shootout.alioth.debian.org | |
# | |
# contributed by Jesse Millikan | |
# Modified by Wesley Moxam | |
def item_check(left, item, right) | |
return item if left.nil? | |
item + item_check(*left) - item_check(*right) | |
end | |
def bottom_up_tree(item, depth) | |
return [nil, item, nil] unless depth > 0 | |
item_item = 2 * item | |
depth -= 1 | |
[bottom_up_tree(item_item - 1, depth), item, bottom_up_tree(item_item, depth)] | |
end | |
max_depth = ARGV[0].to_i | |
min_depth = 4 | |
max_depth = min_depth + 2 if min_depth + 2 > max_depth | |
stretch_depth = max_depth + 1 | |
stretch_tree = bottom_up_tree(0, stretch_depth) | |
puts "stretch tree of depth #{stretch_depth}\t check: #{item_check(*stretch_tree)}" | |
stretch_tree = nil | |
long_lived_tree = bottom_up_tree(0, max_depth) | |
min_depth.step(max_depth + 1, 2) do |depth| | |
iterations = 2**(max_depth - depth + min_depth) | |
check = 0 | |
for i in 1..iterations | |
temp_tree = bottom_up_tree(i, depth) | |
check += item_check(*temp_tree) | |
temp_tree = bottom_up_tree(-i, depth) | |
check += item_check(*temp_tree) | |
end | |
puts "#{iterations * 2}\t trees of depth #{depth}\t check: #{check}" | |
end | |
puts "long lived tree of depth #{max_depth}\t check: #{item_check(*long_lived_tree)}" |
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