binarytrees-list.pn

n = 20
mindepth = 4
maxdepth = mindepth + 2
if (maxdepth < n): maxdepth = n.

new_tree = (item, depth):
  if (depth > 0):
    i = item + item, depth--
    (item, new_tree(i - 1, depth), new_tree(i, depth)).
  else:
    (item).
.

item_check = (tree):
  if (tree(2)):
    tree(0) + item_check(tree(1)) - item_check(tree(2)).
  else:
    tree(0).
.

stretch_depth = maxdepth + 1
check = item_check(new_tree(0, stretch_depth))
("stretch tree of depth ", stretch_depth,
 "\t check: ", check, "\n") join print

longlivedtree = new_tree(0, maxdepth)

depth = mindepth, while (depth <= maxdepth):
  iter = 1 << (maxdepth - depth + mindepth)
  check = 0
  i = 1
  while (i <= iter):
    check = check + item_check(new_tree(1, depth)) +
      item_check(new_tree(-1, depth))
    i++.
  (iter * 2, "\t trees of depth ", depth,
   "\t check: ", check, "\n") join print
  depth = depth + 2.

("long lived tree of depth ", maxdepth, "\t check: ",
 item_check(longlivedtree), "\n") join print