# end of binary tree
return False
# Current level match up and next node match up with either child node
return probe_head.val == probe_root.val and \
(downward_probe(probe_head.next, probe_root.left) or downward_probe(probe_head.next, probe_root.right))
if not root:
# Empty tree
return False
# Start downward path from probe_root
# or wait until child node to start downward path
return downward_probe(head, root) or is_sub_path(
head, root.left) or is_sub_path(head, root.right)
test_cases = [
([4, 2, 8],
[1, 4, 4, None, 2, 2, None, 1, None, 6, 8, None, None, None, None, 1,
3], True),
([1, 4, 2, 6],
[1, 4, 4, None, 2, 2, None, 1, None, 6, 8, None, None, None, None, 1,
3], True),
([1, 4, 2, 6, 8],
[1, 4, 4, None, 2, 2, None, 1, None, 6, 8, None, None, None, None, 1,
3], False)
]
for build_list, build_tree, expected_output in test_cases:
assert is_sub_path(
LinkedList.create_linked_list(build_list).head,
ConstructTree.build_tree_leetcode(build_tree).root) is expected_output
fast_pointer = slow_pointer = head
prev_pointer = None
while fast_pointer and fast_pointer.next:
fast_pointer = fast_pointer.next.next
tmp_pointer = slow_pointer.next
slow_pointer.next = prev_pointer
prev_pointer = slow_pointer
slow_pointer = tmp_pointer
if fast_pointer:
# odd length case
slow_pointer = slow_pointer.next
while slow_pointer:
if slow_pointer.val != prev_pointer.val:
return False
slow_pointer = slow_pointer.next
prev_pointer = prev_pointer.next
return True
test_cases = [([1, 2, 2, 1], True),
([1, 2], False),
([1, 2, 3, 4, 5, 4, 3, 2, 1], True),
([1, 2, 3, 4, 4, 3, 2, 1], True),
([1, 2, 3, 4, 5, 4, 2, 1], False),
([1, 2, 3, 4, 5, 6, 3, 2, 1], False), ]
for test_list, expected_output in test_cases:
assert is_palindrome(head=LinkedList.create_linked_list(test_list).head) is expected_output
elif carry_over:
current_node.next = ListNode(carry_over)
return dummy_node.next
test_cases = [
([2, 4, 3], [5, 6, 4], [7, 0, 8]),
([0], [0], [0]),
([1, 8], [0], [1, 8]),
([9, 9, 9, 9, 9, 9, 9], [9, 9, 9, 9], [8, 9, 9, 9, 0, 0, 0, 1]),
([
2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3,
2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3,
2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 9
], [
5, 6, 4, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3,
2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3, 2, 4, 3,
2, 4, 3, 2, 4, 3, 2, 4, 3, 9, 9, 9, 9
], [
7, 0, 8, 4, 8, 6, 4, 8, 6, 4, 8, 6, 4, 8, 6, 4, 8, 6, 4, 8, 6, 4, 8, 6,
4, 8, 6, 4, 8, 6, 4, 8, 6, 4, 8, 6, 4, 8, 6, 4, 8, 6, 4, 8, 6, 4, 8, 6,
4, 8, 6, 4, 8, 6, 4, 8, 6, 1, 4, 3, 9, 1
]),
]
for input_1, input_2, expected_output in test_cases:
assert add_two_number(
l1=LinkedList.create_linked_list(input_1).head,
l2=LinkedList.create_linked_list(
input_2).head).list_from_node() == expected_output
assert not new_bst.look_up(14)
for i in range(len(values)):
deletion_tree = deepcopy(new_bst)
assert deletion_tree.delete_node(values[i])
assert deletion_tree.is_valid()
# print('Deleted: %d, Remaining: %s' % (values[i], str(deletion_tree.traversal())))
assert deletion_tree.traversal() == values[:i] + values[i + 1:]
expected_values = [6, 7, 8, 9, 10, 11, 12, 13]
assert new_bst.traverse_range(6, 13) == expected_values
assert new_bst.traverse_range(6, 14) == expected_values
assert new_bst.traverse_range(5.5, 13) == expected_values
sorted_list = list(range(1, 11))
head = LinkedList.create_linked_list(sorted_list)
new_bst = BST(head)
assert new_bst.traversal() == sorted_list
assert new_bst.is_balanced()
new_bst = BST([-1])
new_bst.root.right = TreeNode(1)
new_bst.root.right.left = TreeNode(-1)
assert new_bst.is_valid()
new_bst = BST([1])
new_bst.root.left = TreeNode(-1)
new_bst.root.left.right = TreeNode(1)
assert not new_bst.is_valid()
new_bst = BST([1, 3, 4])
]),
(list(range(9)), [
0,
8,
1,
7,
2,
6,
3,
5,
4,
]),
([
1,
], [
1,
]),
([
1,
2,
], [
1,
2,
]),
]
for test_input, test_output in test_cases:
test_head = LinkedList.create_linked_list(test_input).head
assert test_head.list_from_node() == test_input
reorder_list(head=test_head)
assert test_head.list_from_node() == test_output
:param head: head of a linked list, can be None
:param val: remove all elements from linked list that equals to val
:return: head of the remaining linked list, return None if nothing left
"""
while head and head.val == val:
head = head.next
if head is None:
return None
current_node = head
while current_node.next:
if current_node.next.val == val:
current_node.next = current_node.next.next
else:
current_node = current_node.next
return head
N, l = 1000, 300
a, b = -100, 100
for i in range(N):
test_target = randint(a, b)
test_input_list = [test_target] + [randint(a, b) for _ in range(l)]
test_output_list = list(filter(lambda x: x != test_target,
test_input_list))
get_output = remove_elements(
LinkedList.create_linked_list(test_input_list).head, test_target)
assert get_output.list_from_node() == test_output_list
assert remove_elements(
LinkedList.create_linked_list([1] * randint(10, 50)).head, 1) is None
assert remove_elements(None, 1) is None
"""
dummy_node = probe_node = proceeding_node = ListNode(0, next=head)
for _ in range(n):
# 1 <= n <= length of list guaranteed; does not need to check for boundary condition
probe_node = probe_node.next
while probe_node.next:
probe_node = probe_node.next
proceeding_node = proceeding_node.next
proceeding_node.next = proceeding_node.next.next
return dummy_node.next
test_cases = [
([1, 2, 3, 4, 5], 1, [1, 2, 3, 4]),
([1, 2, 3, 4, 5], 2, [1, 2, 3, 5]),
([1, 2, 3, 4, 5], 5, [2, 3, 4, 5]),
([1], 1, []),
([1, 2], 1, [1]),
([5, 6, 9, 8, 6, 4, 5, 1, 9, 8, 7, 2, 8, 6, 8, 3, 5, 8,
6], 17, [5, 6, 8, 6, 4, 5, 1, 9, 8, 7, 2, 8, 6, 8, 3, 5, 8, 6]),
]
for test_list, test_n, expected_output in test_cases:
return_head = remove_nth_node(
LinkedList.create_linked_list(test_list).head, test_n)
if expected_output:
assert return_head.list_from_node() == expected_output
else:
assert return_head is None
test_cases = [
([1, 2, 3, 4, 5, 6], 2, 5),
([1, 2, 3, 4, 5], 2, 4),
([5], 1, 1),
([-5, 4, -2, -2, -2, 3, -3], 6, 6),
([
-18, -29, 30, 10, -45, -93, 9, -4, -52, 91, 61, 91, 19, 32, -100, 34,
38, 99, -93, -37, 73, -67, -29, 52, 6, -50, -87, -33, 6, -72, 72, 89,
-51, -48, -52, -45, -41, 7, 1, -42, -3, -38, -52, 66, 44, 99, 0, -19,
47, 7, 44, 19, -10, 65, -30, 96, -86, -17, -87, -29, -39, 85, -41, -39,
87, -43, -34, -54, 65, 67, 4, -39, 79, 2, -73, 23, 0, -23, 54, 97, 34,
-2, -35, -77, -88, -14, 69, 78, 19, 82, -52, 81, 17, -43, 92, 3, 14,
-43, 49, -22, 74, -98, -10, 53, 4, -33, -75, 54, 44, 79, 50, -73, -74,
66, -50, -61, -49, -82, -84, 70, -100, -86, 0, 17, -29, -59, 70, 85,
-2, 19, -87, -78, -29, -47, 75, 26, -30, 100, -21, 64, 28, 80, 91, 55,
45, -60, 94, 46, -42, 60, 15, -92, 74, -85, -25, -56, -44, -55, 79, 5,
14, 42, -23, 35, 95, -49, -40, -86, -100, -10, 78, 28, -31, 68, -18,
64, -93, -75, -41, -84, 85, 74, 75, 8, 39, -100, 2, 46, 96, -69, -100,
-41, 73, -23, 94, 18, -22, -46, 32, -22, 44, 10, 56, 63, -23, 89, -24,
-65, -87, 35, -99, 49, 8, 76, -44, 98, 26, 9, 43, 21, 40, -7, 80, 12,
70, 74, 80, -53, -73, 12, -25, 21, 72, -70, -17, -52, -82, 59, -67, 83,
-7, -66, 31, 51, 61, 37, 48, -14, -55, -60, 58, 85, 33, 37, -53, -48,
-40, -74, -51, -63, -12, 24, 58, -41, 5, 91, -42, -27, 49, -9, -95, 92,
-24, 36, -7, 87, -77, 91, -78, -82, 82, 80, 54, -36, -33, -100, 17, 27,
77, 16, 65, -35, -60, -28, 24, -5, -37, 82, 18, 62, -77, 24, 4, -1, -41
], 209, 286),
]
for test_list, test_left, test_right in test_cases:
assert reverse_between(LinkedList.create_linked_list(test_list).head, test_left, test_right).list_from_node() == \
test_list[:test_left - 1] + list(reversed(test_list[test_left - 1: test_right])) + test_list[test_right:]
if current_b.next:
# traverse down the list
current_b = current_b.next
elif continue_b:
# switch to list a to finish the remaining len_a steps
current_b, continue_b = head_a, False
else:
# cap out at len_a + len_b + len_c steps
# no need to traverse more
return None
return current_a
test_cases = [
([4, 1], [5, 6, 1], [8, 4, 5]),
([1, 9, 1], [3], [2, 4]),
([2, 6, 4], [1, 5], []),
([4, 1], [5, 6, 1], [8, 4, 5]),
([2, 6, 4], [2, 6, 4], []),
]
for list_a, list_b, list_c in test_cases:
test_head_a = LinkedList.create_linked_list(list_a).head
test_head_b = LinkedList.create_linked_list(list_b).head
test_head_c = LinkedList.create_linked_list(list_c).head
test_head_a.last_node().next = test_head_c
test_head_b.last_node().next = test_head_c
assert get_intersection_node(head_a=test_head_a,
head_b=test_head_b) is test_head_c
current_node.next = l2
return dummy_head.next
test_cases = [
([1, 2, 4], [1, 3, 4], [1, 1, 2, 3, 4, 4]),
([], [], []),
([], [0], [0]),
([
-20, -19, -17, -17, -13, -5, -5, -4, -1, -1, 0, 1, 11, 16, 18, 19, 20,
21, 21, 22, 22, 23, 25, 28, 29
], [
-30, -27, -22, -21, -18, -17, -17, -13, -13, -5, -4, -1, 0, 6, 7, 8,
10, 15, 25, 27
], [
-30, -27, -22, -21, -20, -19, -18, -17, -17, -17, -17, -13, -13, -13,
-5, -5, -5, -4, -4, -1, -1, -1, 0, 0, 1, 6, 7, 8, 10, 11, 15, 16, 18,
19, 20, 21, 21, 22, 22, 23, 25, 25, 27, 28, 29
]),
]
for test_l1_list, test_l2_list, expected_output in test_cases:
if expected_output:
assert merge_two_sorted_lists(LinkedList.create_linked_list(test_l1_list).head,
LinkedList.create_linked_list(test_l2_list).head).list_from_node() \
== expected_output
else:
assert merge_two_sorted_lists(
LinkedList.create_linked_list(test_l1_list).head,
LinkedList.create_linked_list(test_l2_list).head) is None
greater_current.next = head
greater_current = head
head = head.next
greater_current.next = None
less_current.next = greater_dummy.next
return less_dummy.next
test_cases = [
([1, 4, 3, 2, 5, 2], 3),
([2, 1], 2),
([
-4, -4, -6, 8, 3, 7, -5, -8, 0, -3, -5, 5, -1, -3, -4, 3, 4, 0, -3, -6,
9, 4, -7, -6, -8
], 9),
([
-21, -59, 4, -99, 84, -65, -32, -80, 12, -45, 17, -52, 72, -51, -64,
-37, -34, -28, 85, -3, -22, 1, 4, -2, 12, -70, -83, 48, -99, 31, -87,
-19, 24, 18, -66, 8, 5, 2, -20, -83, 10, 49, -35, -66, 99, -46, -3,
-83, -22, -65, 14, 8, -12, 71, -94, -100, -99, 75, 48, -98, -42, 62,
-65, 82, -68, -78, -58, 37, -24, -26, 55, 86, -76, 72, -79, 75, -74,
-30, 92, -43, 5, 7, 65, 93, -70, 24, 93, -69, -1, 42, 85, 58, -44, 73,
-8, -12, 95, -13, 77, -29, 61, -16, -90, 37, -91
], 53),
]
for test_input, test_x in test_cases:
assert partition(LinkedList.create_linked_list(test_input).head, test_x).list_from_node() == \
[x_i for x_i in test_input if x_i < test_x] + [x_i for x_i in test_input if x_i >= test_x]
"""
from _Linked_List import ListNode, LinkedList
def reverse_list(head: ListNode) -> ListNode:
"""
:param head: head of a singly linked list
:return: the head of the reversed list
"""
previous_node, current_node = None, head
while current_node:
next_node = current_node.next
current_node.next = previous_node
previous_node, current_node = current_node, next_node
return previous_node
test_cases = [
[1, 2, 3, 4, 5],
[1, 2],
[],
]
for test_input in test_cases:
test_list = LinkedList.create_linked_list(test_input)
test_list.head = reverse_list(head=test_list.head)
if not test_input:
assert test_list.head is None
else:
assert test_list.head.list_from_node() == test_input[::-1]
from random import randint
from _Linked_Complex import DoubleLinkedList, ComplexLinkedList
from _Linked_List import LinkedList, PrintableLinkedList, ListNode
test_node = ListNode(0)
assert test_node.last_node().val == 0
assert test_node.count_to_last() == 1
node_list = [1, 2, 3, 4, 5]
linked_list = LinkedList.create_linked_list(node_list)
assert node_list == linked_list.head.list_from_node()
assert linked_list.head.last_node().val == 5
assert len(linked_list) == len(node_list)
point_to = linked_list.head
expected_len = len(node_list)
while point_to:
assert point_to.count_to_last() == expected_len
point_to = point_to.next
expected_len -= 1
assert LinkedList.create_linked_list([]).midpoint_of_list() == (0, None)
for list_len in range(1, 8):
midpoint_index, midpoint = LinkedList.create_linked_list(
list(range(1, list_len + 1))).midpoint_of_list()
expected_index = list_len // 2
assert midpoint_index == expected_index and midpoint.val == midpoint_index + 1
printable_list = PrintableLinkedList.create_linked_list(node_list)
separator = ', '
expected_output = separator.join([str(val) for val in node_list])
while l1:
n1 = n1 * 10 + l1.val
l1 = l1.next
while l2:
n2 = n2 * 10 + l2.val
l2 = l2.next
n3 = n1 + n2
return_head = None
while n3 > 0:
return_head = ListNode(n3 % 10, next=return_head)
n3 //= 10
return return_head if return_head else ListNode(0)
test_cases = [
([7, 2, 4, 3], [5, 6, 4], [7, 8, 0, 7]),
([2, 4, 3], [5, 6, 4], [8, 0, 7]),
([0], [0], [0]),
([9, 9, 3], [1], [9, 9, 4]),
([9, 9, 3], [7], [1, 0, 0, 0]),
([5, 5, 5], [4, 9, 5], [1, 0, 5, 0]),
]
for add_two_numbers in [add_two_numbers_stack, add_two_numbers_int]:
for test_l1_list, test_l2_list, expected_output in test_cases:
assert add_two_numbers(
LinkedList.create_linked_list(test_l1_list).head,
LinkedList.create_linked_list(
test_l2_list).head).list_from_node() == expected_output
