def main():
numbers1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
lst1 = DoublyList()
common = None
for idx, n in enumerate(numbers1):
node = Node(n, "hello:%d" % n)
lst1.add_node(node)
if idx == 5:
common = node
lst2 = DoublyList()
numbers2 = [13, 14, 15]
for idx, n in enumerate(numbers2):
lst2.add(n, "hello:%d" % n)
# join them
lst2.tail.next = common
lst2.tail = lst1.tail
assert common == common_node(lst1, lst2)
numbers1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
lst1 = DoublyList()
for idx, n in enumerate(numbers1):
node = Node(n, "hello:%d" % n)
lst1.add_node(node)
lst2 = DoublyList()
numbers2 = [11, 12, 13, 14, 15, 16, 17, 18, 19, 20]
for idx, n in enumerate(numbers2):
lst2.add(n, "hello:%d" % n)
assert None is common_node(lst1, lst2)
def test_insert_before(self):
"""
Tests that a Node can add another Node before it
"""
node = Node(1)
node.insert_before(2)
self.assertEqual(2, node.prev.value)
def insert_at_beginning(head, data):
temp = head
new_node = Node(data)
new_node.next = temp
temp.prev = new_node
head = new_node
return head
def test_insert_after(self):
"""
Tests that a Node can add another Node after it
"""
node = Node(1)
node.insert_after(2)
self.assertEqual(2, node.next.value)
def clone_list(lst):
# step 1
# append new nodes after existing nodes
current = lst.head
while current:
current_next = current.next
new_node = Node(current.key, current.data + " :: new")
current.next = new_node
new_node.next = current_next
current = current_next
# step2
# assign random pointers
current = lst.head
while current:
if current.random:
current.next.random = current.random.next
current = current.next.next
# step 3
# seperate two lists
new_list = DoublyList()
new_head = lst.head.next
new_list.head = new_head
old = lst.head
new = new_head
while old:
old.next = new.next
old = old.next
new.next = old.next if old else None
new = new.next if new else None
return new_list
def test_prepend_adds_an_element_at_the_beginning(self):
first_node = Node(100)
node = Node(1000)
linked = DoublyLinkedList(first_node)
linked.prepend(node)
self.assertEqual(linked.as_list(), [1000, 100])
self.assertIs(linked.first_node, node)
self.assertIs(linked.first_node.next, first_node)
self.assertIs(first_node.previous, node)
def main():
n1 = Node(1, None, None)
n2 = Node(2, None, None)
n3 = Node(1, None, None)
n4 = Node(3, None, None)
l = DoubleList()
l.append(n1)
l.append(n2)
l.append(n3)
l.append(n4)
print(is_palindrome(l))
def enqueue(self, val):
"""Add new element to end of the queue."""
new_node = Node(self, val)
if self.linked_list.head is None:
self.linked_list.head = new_node
self.linked_list.tail = new_node
else:
self.linked_list.tail.prev_node == new_node
new_node.next_node = self.linked_list.tail
self.linked_list.tail == new_node
def insertion_sort(lt, val):
if lt.len == 0:
lt.addNodeE(Node(val))
else:
current = lt.head
while True:
if current.val <= val:
if current.next != None:
current = current.next
else:
lt.addNodeE(Node(val))
break
else:
node = Node(val)
temp = current.prev
current.setPrev(node)
node.setNext(current)
if temp != None:
node.setPrev(temp)
temp.setNext(node)
else:
lt.head = node
lt.len += 1
break
return lt
def test_delete(self):
node_list = [
Node(1),
Node(1),
Node(1),
Node(2),
Node(2),
Node(9),
Node(9),
Node(10)
]
self.list.add_in_tail(node_list[0])
self.list.delete(1)
self.assertIsNone(self.list.head)
self.assertIsNone(self.list.tail)
for node in node_list:
self.list.add_in_tail(node)
self.list.delete(1)
self.assertEqual(self.list.head, node_list[1])
self.assertIsNone(self.list.head.prev)
self.list.delete(10)
self.assertEqual(self.list.tail, node_list[-2])
self.assertIsNone(self.list.tail.next)
self.list.delete(2)
self.assertEqual(self.list.head.next.next, node_list[4])
self.assertIsNotNone(self.list.head.next.next.prev)
self.assertIsNotNone(self.list.head.next.next.next)
def test_node_has_attributes():
"""Test that the node has attributes."""
from doubly_linked_list import Node
n = Node(1, None)
assert n.data
assert n.next_node is None
assert n.previous_node is None
def test_insert_at_position_one(self):
linked = get_instance()
second_node = Node(1000)
linked.insert(second_node, 1)
self.assertEqual(linked.as_list(),
[100, 1000, 200, 300, 400])
def put(self, value):
if value in self.cache_table:
new_node = self.cache_table[value]
if new_node == self.cache_list.tail:
return
elif new_node == self.cache_list.head:
self.cache_list.delete_with_data(new_node)
self.cache_list.insert_at_end(new_node)
else:
self.cache_list.tail.prev.next = new_node
new_node.prev.next = self.cache_list.tail #1
new_node.next.prev = self.cache_list.tail #2
self.cache_list.tail.next = new_node.next #3
self.cache_list.tail.prev.next = new_node #4
# import pdb; pdb.set_trace()
new_node.prev, self.cache_list.tail.prev = self.cache_list.tail.prev, new_node.prev # 5 and 6
new_node.next = None # 7
self.cache_list.tail = new_node #8
else:
new_node = Node(value, None, None)
if self.cache_list.length < self.size:
self.cache_list.insert_at_end(value)
self.cache_table[value] = self.cache_list.tail
else:
del self.cache_table[self.cache_list.head.data]
self.cache_list.delete_from_beginning()
self.cache_list.insert_at_end(value)
self.cache_table[value] = self.cache_list.tail
def test_node_has_attributes():
"""Test node."""
from doubly_linked_list import Node
n = Node(1, None, None)
assert hasattr(n, 'data')
assert hasattr(n, 'next')
assert hasattr(n, 'prev')
def test_insert_at_the_end(self):
linked = get_instance()
second_node = Node(1000)
linked.insert(second_node, 3)
self.assertEqual(linked.as_list(),
[100, 200, 300, 1000, 400])
def test_insert(self):
list_test = LinkedList2()
node_1000 = Node(1000)
list_test.insert(None, node_1000)
self.assertEqual(get_list_nodes(list_test), [1000])
self.assertEqual(list_test.tail.next, None)
self.assertEqual(list_test.head.prev, None)
self.assertEqual(list_test.tail.value, 1000)
self.assertEqual(list_test.head.value, 1000)
self.assertEqual(list_test.head.next, None)
self.assertEqual(list_test.tail.prev, None)
list_test = LinkedList2()
node_12 = Node(12)
node_73 = Node(73)
node_1000 = Node(1000)
list_test.add_in_tail(node_12)
list_test.add_in_tail(node_73)
list_test.insert(node_12, node_1000)
self.assertEqual(get_list_nodes(list_test), [12, 1000, 73])
self.assertEqual(list_test.head.next.value, 1000)
self.assertEqual(list_test.head.next.next.value, 73)
self.assertEqual(list_test.tail.prev.value, 1000)
self.assertEqual(list_test.tail.next, None)
self.assertEqual(list_test.tail.prev.next.value, 73)
list_test = LinkedList2()
node_12 = Node(12)
node_1000 = Node(1000)
list_test.add_in_tail(node_12)
list_test.insert(node_12, node_1000)
self.assertEqual(get_list_nodes(list_test), [12, 1000])
self.assertEqual(list_test.head.next.value, 1000)
self.assertEqual(list_test.tail.prev.value, 12)
self.assertEqual(list_test.tail.next, None)
self.assertEqual(list_test.tail.prev.next.value, 1000)
lst = LinkedList2()
node_1000 = Node(1000)
node_10 = Node(10)
node_12 = Node(12)
lst.add_in_tail(node_10)
lst.add_in_tail(node_12)
lst.insert(node_12, node_1000)
self.assertEqual(get_list_nodes(lst), [10, 12, 1000])
self.assertEqual(lst.head.next.next.value, 1000)
self.assertEqual(lst.tail.prev.value, 12)
self.assertEqual(lst.tail.next, None)
self.assertEqual(lst.tail.prev.next.value, 1000)
class LRUcache(object):
def __init__(self,size=None):
self.cache_list = Node()
self.cache_table = {}
self.size = size
def _add_to_list(self,value):
new_node = self.cache_table[value]
if new_node == self.cache_list.tail:
return
elif new_node == self.cache_list.head:
self.cache_list.delete_with_data(new_node)
self.cache_list.insert_at_end(new_node)
else:
self.cache_list.tail.prev.next = new_node
new_node.prev.next = self.cache_list.tail #1
new_node.next.prev = self.cache_list.tail #2
self.cache_list.tail.next = new_node.next #3
self.cache_list.tail.prev.next = new_node #4
new_node.prev, self.cache_list.tail.prev = self.cache_list.tail.prev, new_node.prev # 5 and 6
new_node.next = None # 7
self.cache_list.tail = new_node #8
def put(self,value):
# import pdb; pdb.set_trace()
if value in self.cache_table:
self._add_to_list(value)
else:
if self.cache_list.length < self.size:
self.cache_list.insert_at_end(value)
self.cache_table[value] = self.cache_list.tail
else:
del self.cache_table[self.cache_list.head.data]
self.cache_list.delete_from_beginning()
self.cache_list.insert_at_end(value)
self.cache_table[value] = self.cache_list.tail
def get(self,value):
if value in self.cache_table:
node = self.cache_table[value]
self._add_to_list(value)
print (node.data)
else:
return -1
def test_prepend_adds_an_element_at_the_beginning_even_without_a_first_node(self):
linked = DoublyLinkedList()
node = Node(1000)
linked.prepend(node)
self.assertEqual(linked.as_list(), [1000])
self.assertIs(linked.first_node, node)
self.assertIs(linked.first_node.next, None)
self.assertIs(linked.first_node.previous, None)
def test_delete_node(self):
"""
Tests that a Node can delete itself
"""
node = Node(1)
node.insert_after(2)
next = node.next
node.insert_before(5)
prev = node.prev
node.delete()
self.assertEqual(next.prev.value, 5)
self.assertEqual(prev.next.value, 2)
def __merge_sort(lst, frm, _to):
if frm is _to:
new_lst = DoublyList()
new_node = Node.from_another_node(frm)
new_lst.add_node(new_node)
return new_lst
mid = middle(lst, frm, _to)
left = __merge_sort(lst, frm, mid)
right = __merge_sort(lst, mid.next, _to)
return merge(left, right)
def test_delete_3(self):
self.list_test = LinkedList2()
self.list_test.delete(12)
self.assertEqual(get_list_nodes(self.list_test), [])
self.list_test = LinkedList2()
self.list_test.add_in_tail(Node(12))
self.list_test.delete(12)
self.assertEqual(get_list_nodes(self.list_test), [])
self.list_test = LinkedList2()
self.list_test.add_in_tail(Node(12))
self.list_test.delete(10)
self.assertEqual(get_list_nodes(self.list_test), [12])
self.list_test = LinkedList2()
self.list_test.add_in_tail(Node(11))
self.list_test.add_in_tail(Node(12))
self.list_test.add_in_tail(Node(73))
self.list_test.delete(73)
self.assertEqual(get_list_nodes(self.list_test), [11, 12])
def setUp(self):
self.list_test = LinkedList2()
self.list_test.add_in_tail(Node(12))
self.list_test.add_in_tail(Node(73))
self.list_test.add_in_tail(Node(73))
self.list_test.add_in_tail(Node(12))
self.list_test.add_in_tail(Node(73))
self.list_test.add_in_tail(Node(73))
def test_find_all(self):
lst = self.list_test.find_all(12)
list_value = [node.value for node in lst]
self.assertEqual(list_value, [12, 12])
list_test = LinkedList2()
self.assertEqual(list_test.find_all(12), [])
list_test = LinkedList2()
list_test.add_in_tail(Node(12))
lst = list_test.find_all(12)
list_value = [node.value for node in lst]
self.assertEqual(list_value, [12])
def add(self, elem):
self._validate(elem)
new = Node(elem)
if self.is_empty():
self.head = new
self.tail = new
else:
current = self.head
next_ = current.get_next()
while current is not None:
if self._is_head(new) or self._is_tail(new) or self._is_middle(
new, current, next_):
return True
current = current.get_next()
next_ = next_.get_next()
return False
def test_find_all(self):
node_list = [
Node(1),
Node(1),
Node(1),
Node(2),
Node(2),
Node(9),
Node(9),
Node(10)
]
for node in node_list:
self.list.add_in_tail(node)
self.assertEqual(self.list.find_all(1), node_list[0:3])
self.assertEqual(self.list.find_all(2), node_list[3:5])
self.assertEqual(self.list.find_all(9), node_list[5:7])
self.assertEqual(self.list.find_all(10), node_list[-1:])
self.assertEqual(self.list.find_all(3123), [])
def insert(self, key, value):
if key in self.cache:
node = self.cache[key]
node.data = (key, value)
self.queue.removeNode(node)
self.queue.insert_node(node, 0)
else:
new_node = Node((key, value))
evicted_value = None
if len(self.cache) >= self.capacity:
lru_node = self.queue.tail
lru_key, evicted_value = lru_node.data
del self.cache[lru_key]
self.queue.removeNode(lru_node)
self.cache[key] = new_node
self.queue.insert_node(new_node, 0)
return evicted_value
def test_clean(self):
node_list = [
Node(1),
Node(1),
Node(1),
Node(2),
Node(2),
Node(9),
Node(9),
Node(10)
]
for node in node_list:
self.list.add_in_tail(node)
self.list.clean()
self.assertEqual(self.list.len(), 0)
self.assertIsNone(self.list.head)
self.assertIsNone(self.list.tail)
def test_find(self):
node_list = [
Node(1),
Node(1),
Node(1),
Node(2),
Node(2),
Node(9),
Node(9),
]
for node in node_list:
self.list.add_in_tail(node)
self.assertEqual(self.list.find(1), node_list[0])
self.assertEqual(self.list.find(2), node_list[3])
self.assertEqual(self.list.find(9), node_list[5])
self.assertIsNone(self.list.find(123))
def test_delete_all(self):
node_list = [
Node(1),
Node(1),
Node(1),
Node(2),
Node(2),
Node(9),
Node(9),
Node(10)
]
for node in node_list:
self.list.add_in_tail(node)
self.list.delete(1, True)
self.assertEqual(self.list.head, node_list[3])
self.assertIsNone(self.list.head.prev)
self.list.delete(10, True)
self.assertEqual(self.list.tail, node_list[-2])
self.assertIsNone(self.list.tail.next)
self.list.delete(2, True)
self.assertEqual(self.list.head, node_list[-3])
self.assertIsNone(self.list.head.prev)
def insert_at_position(DL, n, data):
"""
This function should insert an element in a doubly linked list at a specific position.
E.g. After executing insert_at_position(DL, 2, 88) with DL = 10 <-> 67 <-> 87 <-> 9
It should be DL = 10 <-> 88 <-> 67 <-> 87 <-> 9
Note 1: try to implement this function in the fastest way possible (...how?)
Note 2: be careful at how you manage insertion at the head of the list (position 1) and at the tail (position DL.__len__())
:param DL: a doubly linked list
:param n: the position at which n should be inserted
:param data: the element to insert
"""
len = DL.__len__()
if n > len + 1 or n <= 0:
print("Insert fail: wrong position")
return
if n == len + 1:
DL.add(data)
return
else:
new_node = Node(data, None, None)
if n < len / 2:
walk = DL._head
for i in range(n - 1):
walk = walk._next
if n != 1:
new_node._prev = walk._prev
walk._prev._next = new_node
new_node._next = walk
walk._prev = new_node
if n == 1:
DL._head = new_node
else:
walk = DL._tail
for i in range(len - n):
walk = walk._prev
new_node._prev = walk._prev
walk._prev._next = new_node
new_node._next = walk
walk._prev = new_node
if n == 1:
DL._head = new_node
return
def addAtStart(self, value): tempNode = Node(value) self.head.prev = tempNode tempNode.next = self.head self.head = tempNode self.printList()
