class Solution:
def reverseList(self, head: ListNode) -> ListNode:
dummyHead = ListNode(-1)
while head:
node = ListNode(head.val)
node.next = dummyHead.next
dummyHead.next = node
head = head.next
return dummyHead.next
# 三游标
class Solution2:
def reverseList(self, head: ListNode) -> ListNode:
pre = None
cur = head
while cur:
next = cur.next
cur.next = pre
pre = cur
cur = next
return pre
if __name__ == '__main__':
nums = [1, 2, 3, 4, 5]
head = ListNodeUtils.addNodes(nums)
res = Solution2().reverseList(head)
ListNodeUtils.printListNode(res)
if stack1 and stack2:
sumTmp = stack1.pop() + stack2.pop() + x
elif stack2:
sumTmp = stack2.pop() + x
else:
sumTmp = stack1.pop() + x
if sumTmp >= 10:
sumTmp = sumTmp % 10
x = 1
else:
x = 0
node = ListNode(sumTmp)
node.next = dummyHead.next
dummyHead.next = node
if x == 1:
node = ListNode(1)
node.next = dummyHead.next
dummyHead.next = node
return dummyHead.next
if __name__ == '__main__':
# nums1 = [7, 2, 4, 3]
# nums2 = [5, 6, 4]
nums1 = [5]
nums2 = [5]
l1 = ListNodeUtils.addNodes(nums1)
l2 = ListNodeUtils.addNodes(nums2)
res = Solution().addTwoNumbers(l1, l2)
ListNodeUtils.printListNode(res)
from com.leetcode.linkedUtils import ListNode, ListNodeUtils
class Solution:
def isPalindrome(self, head: ListNode) -> bool:
list1 = list()
while head:
list1.append(head.val)
head = head.next
i = 0
j = len(list1) - 1
while i < j:
if list1[i] != list1[j]:
return False
i += 1
j -= 1
return True
if __name__ == '__main__':
nums = [1]
head = ListNodeUtils.addNodes(nums)
res = Solution().isPalindrome(head)
print(res)
import queue
class Solution:
def mergeKLists(self, lists: List[ListNode]) -> ListNode:
pq = queue.PriorityQueue()
for link in lists:
while link:
pq.put(link.val)
link = link.next
dummyHead = ListNode(-1)
cur = dummyHead
while not pq.empty():
node = ListNode(pq.get())
cur.next = node
cur = cur.next
return dummyHead.next
if __name__ == '__main__':
nums1 = [1, 4, 5]
nums2 = [1, 3, 4]
nums3 = [2, 6]
lists = [
ListNodeUtils.addNodes(nums1),
ListNodeUtils.addNodes(nums2),
ListNodeUtils.addNodes(nums3)
]
res = Solution().mergeKLists(lists)
ListNodeUtils.printListNode(res)