def createBtree(self):
root = TreeNode(3)
root.left = TreeNode(9)
subBranch = TreeNode(20)
subBranch.left = TreeNode(15)
subBranch.right = TreeNode(7)
root.right = subBranch
return root
def sortedListToBST(self, head):
"""
:type head: ListNode
:rtype: TreeNode
"""
node = head
if node is None:
return None
if node.next is None:
return TreeNode(node.val)
# transfer linked list to array
array_whole = [node.val]
while node.next:
node = node.next
array_whole.append(node.val)
mid = int(len(array_whole) / 2)
root = TreeNode(array_whole[mid])
# split the array
array_l = array_whole[:mid]
array_r = [] if mid == len(array_whole) - 1 else array_whole[mid + 1:]
# processing left
if len(array_l) > 0:
node = ListNode(array_l.pop(0))
head_l = node
while array_l:
node.next = ListNode(array_l.pop(0))
node = node.next
root.left = self.sortedListToBST(head_l)
else:
root.left = None
# processing right
if len(array_r) > 0:
node = ListNode(array_r.pop(0))
head_r = node
while array_r:
node.next = ListNode(array_r.pop(0))
node = node.next
root.right = self.sortedListToBST(head_r)
else:
root.right = None
return root
def testCase2(self):
root = TreeNode(-10)
root.left = TreeNode(9)
root.right = TreeNode(20)
root.right.left = TreeNode(15)
root.right.right = TreeNode(7)
return root
def testCase3(self):
root = TreeNode(1)
root.left = TreeNode(2)
root.left.left = TreeNode(2)
root.left.right = TreeNode(3)
root.right = TreeNode(4)
return root
def testCase4(self):
root = TreeNode(-5)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.right.left = TreeNode(-1)
root.right.right = TreeNode(4)
return root
def constructCase2(self):
from customDataType import TreeNode
root = TreeNode(0)
root.left = TreeNode(1)
root.left.right = TreeNode(2)
root.left.right.right = TreeNode(3)
root.left.right.right.right = TreeNode(4)
return root, root.left.right.right, 0
def constructCase(self):
from customDataType import TreeNode
root = TreeNode(4)
root.left = TreeNode(9)
root.right = TreeNode(0)
root.left.left = TreeNode(5)
root.left.right = TreeNode(1)
root.left.left.left = TreeNode(8)
return root
def testCase(self):
root = TreeNode(3)
root.left = TreeNode(9)
# root.left.right = TreeNode(4)
root.left.left = TreeNode(15)
# root.left.left.left = TreeNode(7)
root.right = TreeNode(20)
# root.right.left = TreeNode(15)
# root.right.right = TreeNode(7)
return root
def testCase(self):
root = TreeNode(5)
root.left = TreeNode(4)
root.left.left = TreeNode(11)
root.left.left.left = TreeNode(7)
root.left.left.right = TreeNode(2)
root.right = TreeNode(8)
root.right.left = TreeNode(13)
root.right.right = TreeNode(4)
root.right.right.right = TreeNode(1)
return root, 22
def sortedArrayToBST(self, nums):
"""
:type nums: List[int]
:rtype: TreeNode
"""
L = len(nums)
if L == 0:
return None
m = int(L / 2)
node = TreeNode(nums[m])
node.left = self.sortedArrayToBST(nums[:m])
node.right = self.sortedArrayToBST(nums[m + 1:])
return node