if (node.key == data) :
    return 1

downlevel= 1+getLevel(node.left,
                         data)
if (downlevel != 0) :
    return downlevel

downlevel = 1+getLevel(node.right,
                         data)

return downlevel

path.append(node.key)

if node.key == k :
    return True

if ((node.left != None and pathToNode(node.left, path, k)) or
        (node.right!= None and pathToNode(node.right, path, k))):
    return True

path.pop()
return False

path1 = []
pathToNode(node, path1, x)

path2 = []
pathToNode(node, path2, y)

i=0
while i<len(path1) and i<len(path2):
    if path1[i] != path2[i]:
        break
    i = i+1


return (len(path1)+len(path2)-2*i)

def __init__(self, item):
    self.key=item
    self.left = None
    self.right = None

list = []

if (start > end) :

    list.append(None)
    return list

for i in range(start, end + 1):
    leftSubtree = constructTrees(start, i - 1)
    rightSubtree = constructTrees(i + 1, end)
    for j in range(len(leftSubtree)) :
        left = leftSubtree[j]
        for k in range(len(rightSubtree)):
            right = rightSubtree[k]
            node=newNode(i)
            node.left = left
            node.right = right
            list.append(node)
return list