def list_to_tree(l):
if not l: return None
mid = (len(l)-1)/2
n = Node(l[mid])
n.left = list_to_tree(l[:mid])
n.right = list_to_tree(l[(mid+1):])
return n
def recurse(l,left,right):
if left > right: return None
mid = (left+right)/2
n = Node(l[mid])
n.left = recurse(l,left,mid-1)
n.right = recurse(l,mid+1,right)
return n
def double(node):
if not node: return
n = Node(node.val)
old_left = node.left
n.left = old_left
node.left = n
double(old_left)
double(node.right)
def list_to_tree_parent(l):
if not l: return None
mid = (len(l)-1)/2
n = Node(l[mid])
n.parent = None
n.left = list_to_tree_parent(l[:mid])
if n.left: n.left.parent = n
n.right = list_to_tree_parent(l[(mid+1):])
if n.right: n.right.parent = n
return n
