def main(self):
root = [3,5,1,6,2,0,8,None,None,7,4]
p = TreeNode(5)
q = TreeNode(1)
root = Tree().build_tree_from_level_recur_list(root)
Tree().mid_recur_tree(root)
self.lowestCommonAncestor(root, p, q)
def build_tree_assist(ps, pe, ins, ine):
if (ps >= pe or ins >= ine):
return None
root = TreeNode(preorder[ps])
root_pos = in_map[root.val]
root.left = build_tree_assist(ps + 1, ps + root_pos - ins + 1, ins,
root_pos)
root.right = build_tree_assist(ps + root_pos - ins + 1, pe,
root_pos + 1, ine)
return root
def build_tree(expression):
if not expression:
return None
else:
signi = expression.pop()
root = TreeNode(signi)
if signi in '+-*/':
root.right = build_tree(expression)
root.left = build_tree(expression)
return root
def build_tree(trs):
if not trs:
return None
else:
val = trs.pop(0)
if val == '#':
return None
else:
root = TreeNode(val)
root.left = build_tree(trs)
root.right = build_tree(trs)
return root
def gen_tree(s, e):
if s >= e:
return [None]
else:
all_trees = []
for i in range(s, e):
left = gen_tree(s, i)
right = gen_tree(i + 1, e)
for l in left:
for r in right:
rooti = TreeNode(i)
rooti.left = l
rooti.right = r
all_trees.append(rooti)
return all_trees
def parse_str(start, end):
if start < end:
i = start
while i < end and s[i] not in '()':
i += 1
cur_node = TreeNode(int(s[start:i]))
if i + 1 < end:
left_start, left_end = i + 1, record[i]
cur_node.left = parse_str(left_start, left_end)
if left_end < end - 1:
right_start, right_end = left_end + 2, record[left_end
+ 1]
cur_node.right = parse_str(right_start, right_end)
return cur_node
else:
return None
def insert(root, val):
if not root:
return TreeNode(val)
if root.val == val:
return root
if val < root.val:
root.left = insert(root.left, val)
else:
root.right = insert(root.right, val)
return root
def build_tree(pre, post):
if len(pre) == 1:
return TreeNode(pre[0])
elif pre and post:
root = TreeNode(pre[0])
pre_index = pre.index(post[-2])
post_index = post.index(pre[1])
left_pre = pre[1:pre_index]
left_post = post[:post_index + 1]
right_pre = pre[pre_index:]
right_post = post[post_index + 1:len(pre) - 1]
if left_pre and left_post:
root.left = build_tree(left_pre, left_post)
root.right = build_tree(right_pre, right_post)
elif not left_pre:
root.left = build_tree(right_pre, left_post)
else:
root.right = build_tree(left_pre, right_post)
return root
else:
return None
def main(self):
root = [6, 2, 8, 0, 4, 7, 9, None, None, 3, 5]
p = TreeNode(2)
q = TreeNode(8)
root = Tree().build_tree_from_list(root)
self.lowestCommonAncestor(root, p, q)