def addTwoNumbers(self, l1, l2):
"""
:type l1: ListNode
:type l2: ListNode
:rtype: ListNode
"""
reslist, head = None, None
carry = 0
while l1 or l2:
x = l1.val if l1 else 0
y = l2.val if l2 else 0
res = x + y + carry
carry = res // 10
if reslist is None:
reslist = ListNode(res % 10)
head = reslist
else:
reslist.next = ListNode(res % 10)
reslist = reslist.next
if l1:
l1 = l1.next
if l2:
l2 = l2.next
if carry != 0:
reslist.next = ListNode(carry)
return head
def reverseKGroup_Iter(head, k):
dmy = ListNode(-1)
dmy.next = head
tmp_pre = dmy
while (head):
tail = head
cnt = 0
while (tail and cnt < k):
tail = tail.next
cnt += 1
if cnt < k:
tmp_pre.next = head
head = tail
else:
pre = head
while (cnt > 0):
tmp = head.next
head.next = tail
tail = head
head = tmp
cnt -= 1
tmp_pre.next = tail
tmp_pre = pre
return dmy.next
def createLL(n):
head = None
i = n
while (i > 0):
tmp = ListNode(i)
tmp.next = head
head = tmp
i -= 1
return head
def remove_duplicate_node(root: ListNode):
pre = ListNode(0)
memo = set()
pre.next = root
point = pre
while point.next:
if point.next.val not in memo:
memo.add(point.next.val)
point = point.next
else:
point.next = point.next.next
def partition(root: ListNode, part_num: int):
left, right = ListNode("l"), ListNode("r")
left.next = root
point1, point2 = left, right
while point1.next:
node = point1.next
if node.val >= part_num:
point1.next = node.next
node.next = None
point2.next = node
point2 = point2.next
else:
point1 = point1.next
point1.next = right.next
def remove_duplicate_node_without_extra_memory(root: ListNode):
pre = ListNode(0)
pre.next = root
point = pre
while point.next:
point0 = root
flag = False
while point0 != point.next:
if point0.val == point.next.val:
flag = True
point.next = point.next.next
break
point0 = point0.next
if not flag:
point = point.next
def insert_first_node(root: ListNode, val) -> ListNode:
node = ListNode(val)
node.next = root
return node
def remove_node(node: ListNode):
if node.next is None:
return False
node.val = node.next.val
node.next = node.next.next
