def rotateRight(head: ListNode, k: int) -> ListNode:
p = ListNode("NULL", head)
if not p.next or not p.next.next:
return p.next
if not p.next.next.next:
k = k % 2
if k == 0:
return p.next
else:
p.next.next.next = p.next
p.next = p.next.next
p.next.next.next = None
return p.next
node_pointer1 = p.next
length = 1
while node_pointer1.next:
length += 1
node_pointer1 = node_pointer1.next
k = k % length
if k == 0:
return p.next
else:
node_pointer2 = p.next
for i in range(length - 1, k, -1):
node_pointer2 = node_pointer2.next
node_pointer1.next = p.next
p.next = node_pointer2.next
node_pointer2.next = None
return p.next
def addTwoNumbers(l1: ListNode, l2: ListNode) -> ListNode:
def pushInStack(node: ListNode) -> List[int]:
p = node
result = []
while p:
result.append(p.val)
p = p.next
return result
list1 = pushInStack(l1)
list2 = pushInStack(l2)
l3 = ListNode("NULL")
carry = 0
while True:
the_sum = 0
if list1:
the_sum += list1.pop()
if list2:
the_sum += list2.pop()
the_sum += carry
if the_sum > 9:
carry = 1
else:
carry = 0
if not l3.next:
l3.next = ListNode(the_sum % 10)
else:
new_pointer = ListNode(the_sum % 10, l3.next)
l3.next = new_pointer
if not list1 and not list2 and carry == 0:
break
return l3.next
def reverse(node: ListNode) -> None:
pre = None
cur = node.next
la = cur.next
node.next = None
while cur:
cur.next = pre
pre = cur
cur = la
if la:
la = la.next
node.next = pre
def deleteDuplicates(head: ListNode) -> ListNode or None:
val = []
p = ListNode("NULL", head)
pointer = p
while pointer.next:
pointer = pointer.next
val.append(pointer.val)
dic = sorted(set(val))
p.next = None
pointer = p
for num in dic:
pointer.next = ListNode(num)
pointer = pointer.next
return p.next
def deleteDuplicates(head: ListNode) -> ListNode or None:
q = ListNode("NULL", head)
val = {}
pointer = q
while pointer.next:
pointer = pointer.next
if pointer.val not in val.keys():
val.update({pointer.val: 1})
else:
val[pointer.val] += 1
q.next = None
pointer = q
for num in val.keys():
if val[num] == 1:
pointer.next = ListNode(num)
pointer = pointer.next
return q.next
while slow != fast:
slow = slow.next
count += 1
return count
if fast.next:
fast = fast.next
else:
return count
slow = slow.next
return count
size = getCycleSize()
if size > 0:
p = ListNode("NULL", head)
pre = p
for j in range(0, size):
pre = pre.next
last = p.next
while pre.next != last:
last = last.next
pre = pre.next
return last
if __name__ == "__main__":
cycle_end = ListNode(4)
cycle_start = ListNode(2, ListNode(3, cycle_end))
cycle_end.next = cycle_start
test = ListNode(1, cycle_start)
detectCycle(test)
