1# The Computer Language Shootout Benchmarks
2# http://shootout.alioth.debian.org
3#
4# contributed by Jesse Millikan
5
6# disable output
7alias puts_orig puts
8def puts str
9  # disable puts
10end
11
12def item_check(tree)
13 if tree[0] == nil
14  tree[1]
15 else
16  tree[1] + item_check(tree[0]) - item_check(tree[2])
17 end
18end
19
20def bottom_up_tree(item, depth)
21 if depth > 0
22  item_item = 2 * item
23  depth -= 1
24  [bottom_up_tree(item_item - 1, depth), item, bottom_up_tree(item_item, depth)]
25 else
26  [nil, item, nil]
27 end
28end
29
30max_depth = 16 # ARGV[0].to_i
31min_depth = 4
32
33max_depth = min_depth + 2 if min_depth + 2 > max_depth
34
35stretch_depth = max_depth + 1
36stretch_tree = bottom_up_tree(0, stretch_depth)
37
38puts "stretch tree of depth #{stretch_depth}\t check: #{item_check(stretch_tree)}"
39stretch_tree = nil
40
41long_lived_tree = bottom_up_tree(0, max_depth)
42
43min_depth.step(max_depth + 1, 2) do |depth|
44 iterations = 2**(max_depth - depth + min_depth)
45
46 check = 0
47
48 for i in 1..iterations
49  temp_tree = bottom_up_tree(i, depth)
50  check += item_check(temp_tree)
51
52  temp_tree = bottom_up_tree(-i, depth)
53  check += item_check(temp_tree)
54 end
55
56 puts "#{iterations * 2}\t trees of depth #{depth}\t check: #{check}"
57end
58
59puts "long lived tree of depth #{max_depth}\t check: #{item_check(long_lived_tree)}"
60
61undef puts
62alias puts puts_orig
63