def loop_detection(ll):
fast = slow = ll.head
while fast and fast.next:
print(slow.value, fast.value)
fast = fast.next.next
slow = slow.next
if fast == slow:
break
print(slow.value, fast.value)
if fast is None or fast.next is None:
return None
print('---')
slow = ll.head
while fast != slow:
print(slow.value, fast.value)
fast = fast.next
slow = slow.next
print(slow.value, fast.value)
print(fast.value)
ll = LinkedList()
ll.append_multiple([1, 2, 3, 4])
node = Node(5)
ll.append_multiple([node, Node(6), Node(7), Node(8), Node(9), node])
loop_detection(ll)
diff = longer.length - shorter.length
short, long = shorter.head, longer.head
for i in range(diff):
long = long.next
while short is not long:
short = short.next
long = long.next
return long.value
ll_1 = LinkedList()
ll_2 = LinkedList()
ll_1.append_multiple([2, 8, 4, 9, 2])
ll_2.append_multiple([3, 4, 1])
node = Node(5)
ll_1.append(node)
ll_2.append(node)
node = Node(1)
ll_1.append(node)
ll_2.append(node)
ll_1.display()
ll_2.display()
result = intersection(ll_1, ll_2)
print(result)
def sum_lists(ll_a, ll_b):
n1, n2 = ll_a.head, ll_b.head
ll = LinkedList()
carry = 0
while n1 or n2:
result = carry
if n1:
result += n1.value
n1 = n1.next
if n2:
result += n2.value
n2 = n2.next
ll.append(result % 10)
carry = result // 10
if carry:
ll.append(carry)
return ll
ll_a = LinkedList()
ll_a.append_multiple([6, 1, 7])
ll_b = LinkedList()
ll_b.append_multiple([2, 9, 5])
ll_a.display()
ll_b.display()
ll_sum = sum_lists(ll_a, ll_b)
ll_sum.display()
from utils import LinkedList
def delete_middle_node(node):
node.value = node.next.value
node.next = node.next.next
ll = LinkedList()
ll.append_multiple([1, 2, 3, 4])
middle_node = ll.append(5)
ll.append_multiple([6, 7, 8, 9])
ll.display()
delete_middle_node(middle_node)
ll.display()
from utils import LinkedList
def palindrome_runner(ll):
runner = current = ll.head
stack = []
while runner and runner.next:
stack.append(current.value)
current = current.next
runner = runner.next.next
if runner:
current = current.next
while current:
top = stack.pop()
if top != current.value:
return False
current = current.next
return True
ll = LinkedList()
ll.append_multiple([1, 2, 3, 4, 3, 2, 1])
ll.display()
result = palindrome_runner(ll)
print(result)
from utils import LinkedList
def partition(ll, x):
current = ll.tail = ll.head
while current:
nextNode = current.next
current.next = None
if current.value < x:
current.next = ll.head
ll.head = current
else:
ll.tail.next = current
ll.tail = current
current = nextNode
# Error check in case all nodes are less than x
if ll.tail.next is not None:
ll.tail.next = None
return ll
ll = LinkedList()
n = ll.append(55)
ll.append_multiple([82, 95, 20, 47, 37, 11, 42, 91, 6, 74])
ll.display()
print('Patition created at {}'.format(n.value))
ll = partition(ll, n.value)
ll.display()
from utils import LinkedList
def kth_to_last(ll, k):
if k <= 0:
raise (AttributeError('Set k to a value greater than 0'))
current = runner = ll.head
for i in range(k):
runner = runner.next
while runner:
current = current.next
runner = runner.next
return current.value
ll = LinkedList()
ll.append_multiple([1, 2, 3, 4, 5, 6, 7, 8, 9])
kth_to_last = kth_to_last(ll, 2)
print(kth_to_last)
