fabf1c9334
I had a spare fifteen minutes and decided that I should tidy up my monorepo. The work of tidying up is not finished; this is a small step in the right direction. TL;DR - Created a tools directory - Created a scratch directory (see README.md for more information) - Added README.md to third_party - Renamed delete_dotfile_symlinks -> symlinkManager - Packaged symlinkManager as an executable symlink-mgr using buildGo
121 lines
3.8 KiB
Python
121 lines
3.8 KiB
Python
import unittest
|
|
|
|
|
|
################################################################################
|
|
# Implementation
|
|
################################################################################
|
|
# is_leaf :: Node(a) -> Boolean
|
|
def is_leaf(node):
|
|
return not node.left and not node.right
|
|
|
|
|
|
# is_binary_search_tree :: Node(Integer) -> Set(Int) -> Set(Int) -> Boolean
|
|
def is_binary_search_tree_a(node, la=set(), ra=set()):
|
|
"""My first solution for this problem."""
|
|
for x in la:
|
|
if not node.value < x:
|
|
return False
|
|
for x in ra:
|
|
if not node.value > x:
|
|
return False
|
|
if is_leaf(node):
|
|
return True
|
|
elif not node.left:
|
|
return is_binary_search_tree(
|
|
node.right,
|
|
la=la,
|
|
ra=ra ^ {node.value},
|
|
)
|
|
elif not node.right:
|
|
return is_binary_search_tree(node.left, la=la ^ {node.value}, ra=ra)
|
|
else:
|
|
return all([
|
|
is_binary_search_tree(node.left, la=la ^ {node.value}, ra=ra),
|
|
is_binary_search_tree(node.right, la=la, ra=ra ^ {node.value})
|
|
])
|
|
|
|
|
|
# is_binary_search_tree :: Node(Int) -> Maybe(Int) -> Maybe(Int) -> Boolean
|
|
def is_binary_search_tree(node, lb=None, ub=None):
|
|
if lb:
|
|
if node.value < lb:
|
|
return False
|
|
if ub:
|
|
if node.value > ub:
|
|
return False
|
|
if is_leaf(node):
|
|
return True
|
|
elif not node.right:
|
|
return is_binary_search_tree(node.left, lb=lb, ub=node.value)
|
|
elif not node.left:
|
|
return is_binary_search_tree(node.right, lb=node.value, ub=ub)
|
|
else:
|
|
return is_binary_search_tree(
|
|
node.left, lb=lb, ub=node.value) and is_binary_search_tree(
|
|
node.right, lb=node.value, ub=ub)
|
|
|
|
|
|
################################################################################
|
|
# Tests
|
|
################################################################################
|
|
class Test(unittest.TestCase):
|
|
class BinaryTreeNode(object):
|
|
def __init__(self, value):
|
|
self.value = value
|
|
self.left = None
|
|
self.right = None
|
|
|
|
def insert_left(self, value):
|
|
self.left = Test.BinaryTreeNode(value)
|
|
return self.left
|
|
|
|
def insert_right(self, value):
|
|
self.right = Test.BinaryTreeNode(value)
|
|
return self.right
|
|
|
|
def test_valid_full_tree(self):
|
|
tree = Test.BinaryTreeNode(50)
|
|
left = tree.insert_left(30)
|
|
right = tree.insert_right(70)
|
|
left.insert_left(10)
|
|
left.insert_right(40)
|
|
right.insert_left(60)
|
|
right.insert_right(80)
|
|
result = is_binary_search_tree(tree)
|
|
self.assertTrue(result)
|
|
|
|
def test_both_subtrees_valid(self):
|
|
tree = Test.BinaryTreeNode(50)
|
|
left = tree.insert_left(30)
|
|
right = tree.insert_right(80)
|
|
left.insert_left(20)
|
|
left.insert_right(60)
|
|
right.insert_left(70)
|
|
right.insert_right(90)
|
|
result = is_binary_search_tree(tree)
|
|
self.assertFalse(result)
|
|
|
|
def test_descending_linked_list(self):
|
|
tree = Test.BinaryTreeNode(50)
|
|
left = tree.insert_left(40)
|
|
left_left = left.insert_left(30)
|
|
left_left_left = left_left.insert_left(20)
|
|
left_left_left.insert_left(10)
|
|
result = is_binary_search_tree(tree)
|
|
self.assertTrue(result)
|
|
|
|
def test_out_of_order_linked_list(self):
|
|
tree = Test.BinaryTreeNode(50)
|
|
right = tree.insert_right(70)
|
|
right_right = right.insert_right(60)
|
|
right_right.insert_right(80)
|
|
result = is_binary_search_tree(tree)
|
|
self.assertFalse(result)
|
|
|
|
def test_one_node_tree(self):
|
|
tree = Test.BinaryTreeNode(50)
|
|
result = is_binary_search_tree(tree)
|
|
self.assertTrue(result)
|
|
|
|
|
|
unittest.main(verbosity=2)
|