Хранить каждый узел со ссылкой на его родителя. Когда вы добавляете узел в качестве дочернего, подойдите к родителям (из добавляемого узла) и удалите третий, после того как для родительской ссылки во всех его дочерних элементах установлено значение None
. Затем добавьте дочерние элементы удаленного узла в список деревьев.
class Node(object):
depth = 4
def __init__(self, parent, contents):
self.parent = parent
self.contents = contents
self.children = []
def create_node(trees, parent, contents):
"""Adds a leaf to a specified node in the set of trees.
Note that it has to have access to the container that holds all of the trees so
that it can delete the appropriate parent node and add its children as independent
trees. Passing it in seems a little ugly. The container of trees could be a class
with this as a method or you could use a global list. Or something completely
different. The important thing is that if you don't delete every reference to the
old root, you'll leak memory.
"""
parent.children.append(Node(parent, contents))
i = 0:
L = Node.depth - 1
while i < L:
parent = parent.parent
if not parent:
break
i += 1
else:
for node in parent.children:
node.parent = None
trees.extend(parent.children)
i = trees.find(parent)
del trees[i]