# The Computer Language Benchmarks Game
# http://shootout.alioth.debian.org/
#
# contributed by Antoine Pitrou
# modified by Dominique Wahli
# modified by Heinrich Acker

import time

def make_tree(item, depth):
    if not depth: return item, None, None
    item2 = item + item
    depth -= 1
    return item, make_tree(item2 - 1, depth), make_tree(item2, depth)

def check_tree((item, left, right)):
    if not left: return item
    return item + check_tree(left) - check_tree(right)

min_depth = 4
max_depth = 12
stretch_depth = max_depth + 1

start = time.clock()
print "stretch tree of depth %d check:" % stretch_depth, check_tree(make_tree(0, stretch_depth))

long_lived_tree = make_tree(0, max_depth)

iterations = 2**max_depth
for depth in xrange(min_depth, stretch_depth, 2):

    check = 0
    for i in xrange(1, iterations + 1):
        check += check_tree(make_tree(i, depth)) + check_tree(make_tree(-i, depth))

    print "%d trees of depth %d check:" % (iterations * 2, depth), check
    iterations /= 4

print "long lived tree of depth %d check:" % max_depth, check_tree(long_lived_tree)
print("elapsed: " + str(time.clock() - start))