from LeetTool import build_ListNode
class Solution:
def plusOne(self, head: ListNode) -> ListNode:
lst = []
ans = node = ListNode(0)
node.next = head
while node:
lst.append(node)
node = node.next
while lst:
if lst[-1].val < 9:
lst[-1].val += 1
break
else:
lst[-1].val = 0
lst.pop()
if ans.val == 0:
return ans.next
else:
return ans
if __name__ == "__main__":
# [1,2,4]
print(Solution().plusOne(build_ListNode([1, 2, 3])))
from LeetTool import build_ListNode
class Solution:
def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
head = node = ListNode(0)
last = 0 # 进位数量
while l1 or l2 or last:
now = last
if l1:
now += l1.val
l1 = l1.next
if l2:
now += l2.val
l2 = l2.next
last, now = divmod(now, 10)
node.next = ListNode(now)
node = node.next
return head.next
if __name__ == "__main__":
print(Solution().addTwoNumbers(build_ListNode([7, 1, 6]),
build_ListNode([5, 9, 2]))) # 2->1->9
print(Solution().addTwoNumbers(build_ListNode([6, 1, 7]),
build_ListNode([2, 9, 5]))) # 9->1->2
if mm:
node = node.next
mm -= 1
elif nn:
if node.next:
node.next = node.next.next
else:
node.next = None
nn -= 1
else:
mm, nn = m, n
return head
if __name__ == "__main__":
# [1,2,6,7,11,12]
print(Solution().deleteNodes(
build_ListNode([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]), 2, 3))
# [1,5,9]
print(Solution().deleteNodes(
build_ListNode([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]), 1, 3))
# [1,2,3,5,6,7,9,10,11]
print(Solution().deleteNodes(
build_ListNode([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]), 3, 1))
# [9,7,8]
print(Solution().deleteNodes(build_ListNode([9, 3, 7, 7, 9, 10, 8, 2]), 1,
2))
def isPalindrome(self, head: ListNode) -> bool:
i1 = i2 = head
# 快慢针求中点
while i1 and i1.next:
i1 = i1.next.next
i2 = i2.next
# 翻转链表
i3 = None
while i2:
last = i2.next
i2.next = i3
i3 = i2
i2 = last
# 比较链表
i4 = head
while i3 and i4:
if i3.val != i4.val:
return False
i3 = i3.next
i4 = i4.next
return True
if __name__ == "__main__":
print(Solution().isPalindrome(build_ListNode([1, 2]))) # False
print(Solution().isPalindrome(build_ListNode([1, 2, 2, 1]))) # True
from LeetTool import ListNode
from LeetTool import build_ListNode
class Solution:
def kthToLast(self, head: ListNode, k: int) -> int:
i1, i2 = head, head
for _ in range(k - 1):
i1 = i1.next
while i1.next:
i1 = i1.next
i2 = i2.next
return i2.val
if __name__ == "__main__":
print(Solution().kthToLast(build_ListNode([1, 2, 3, 4, 5]), 2)) # 4
from LeetTool import ListNode
from LeetTool import build_ListNode
class Solution:
def swapNodes(self, head: ListNode, k: int) -> ListNode:
n1 = n2 = head
for _ in range(k - 1):
n2 = n2.next
n3 = n2 # 正数第k个节点
while n2.next:
n1 = n1.next
n2 = n2.next
n4 = n1 # 倒数第k个节点
n3.val, n4.val = n4.val, n3.val
return head
if __name__ == "__main__":
print(Solution().swapNodes(build_ListNode([1, 2, 3, 4, 5]), k=2))
print(Solution().swapNodes(build_ListNode([7, 9, 6, 6, 7, 8, 3, 0, 9, 5]),
k=5))
print(Solution().swapNodes(build_ListNode([1]), k=1))
print(Solution().swapNodes(build_ListNode([1, 2]), k=1))
print(Solution().swapNodes(build_ListNode([1, 2, 3]), k=2))
import random
from LeetTool import ListNode
from LeetTool import build_ListNode
class Solution:
def __init__(self, head: ListNode):
self.head = head
def getRandom(self) -> int:
now = 0
idx = 0
node = self.head
while node:
idx += 1
rand = random.randint(1, idx)
if rand == idx:
now = node.val
node = node.next
return now
if __name__ == "__main__":
obj = Solution(build_ListNode([1, 2, 3]))
print(obj.getRandom()) # 1或2或3
def mergeInBetween(self, list1: ListNode, a: int, b: int,
list2: ListNode) -> ListNode:
start, end = None, None
node = list1
while node:
if node.next and node.next.val == a:
start = node
if node.val == b:
end = node.next
node = node.next
node = list2
while node.next:
node = node.next
node.next = end
start.next = list2
return list1
if __name__ == "__main__":
# [0,1,2,1000000,1000001,1000002,5]
print(Solution().mergeInBetween(
build_ListNode([0, 1, 2, 3, 4, 5]), 3, 4,
build_ListNode([1000000, 1000001, 1000002])))
# [0,1,1000000,1000001,1000002,1000003,1000004,6]
print(Solution().mergeInBetween(
build_ListNode([0, 1, 2, 3, 4, 5, 6]), 3, 4,
build_ListNode([1000000, 1000001, 1000002, 1000003, 1000004])))
from LeetTool import ListNode
from LeetTool import build_ListNode
class Solution:
def partition(self, head: ListNode, x: int) -> ListNode:
head1 = node1 = ListNode(0)
head2 = node2 = ListNode(0)
while head:
if head.val >= x:
node2.next = ListNode(head.val)
node2 = node2.next
else:
node1.next = ListNode(head.val)
node1 = node1.next
head = head.next
node1.next = head2.next
return head1.next
if __name__ == "__main__":
# 3->1->2->10->5->5->8
print(Solution().partition(build_ListNode([3, 5, 8, 5, 10, 2, 1]), 5))
from LeetTool import ListNode
from LeetTool import build_ListNode
class Solution:
def deleteNode(self, node):
node.val = node.next.val
node.next = node.next.next
if __name__ == "__main__":
listNode = build_ListNode(["a", "b", "c", "d", "e", "f"])
print(Solution().deleteNode(listNode.next.next))
print(listNode)