else:
node.next = tail
tail = node
node = nextNode
head2 = tail
head = None
tail = None
count = 0
while True:
if count % 2 == 1 and head2:
tail.next = head2
head2 = head2.next
tail = tail.next
elif count % 2 == 0 and head1:
if head == None:
head = head1
tail = head
else:
tail.next = head1
tail = tail.next
head1 = head1.next
else:
break
count += 1
return head
vals = [1,2,3,4,5,6]
head1 = ListNode.build(vals)
print(Solution().reorderList(head1))
if headNode == None:
headNode = l1
if preNode != None:
preNode.next = l1
preNode = l1
l1 = l1.next
preNode.next = None
else:
if l1.val < l2.val:
if headNode == None:
headNode = l1
if preNode != None:
preNode.next = l1
preNode = l1
l1 = l1.next
preNode.next = None
else:
if headNode == None:
headNode = l2
if preNode != None:
preNode.next = l2
preNode = l2
l2 = l2.next
preNode.next = None
return headNode
# @lc code=end
print(Solution().mergeTwoLists(ListNode.build([1, 2, 4]),
ListNode.build([1, 3, 4])))
node.next = lastNode
lastNode = node
if nodeNext != None:
node = nodeNext
else:
head = node
break
return head
# return None if head == None else reverse(None, head)
# stack = []
# while head != None:
# node = head
# ndoeNext = head.next
# node.next = None
# stack.append(node)
# head = ndoeNext
# head = None
# lastNode = None
# while len(stack) > 0:
# node = stack.pop()
# if head == None:
# head = node
# lastNode = node
# else:
# lastNode.next = node
# lastNode = node
# return head
# @lc code=end
print(Solution().reverseList(ListNode.build([1,2,3,4,5])))
# class ListNode:
# def __init__(self, x):
# self.val = x
# self.next = None
from typing import List
import sys
sys.path.append('..')
import sys
import os
sys.path.append(os.path.dirname(os.path.dirname(os.path.realpath(__file__))))
from Tool.Python.ListNode import ListNode
class Solution:
def reversePrint(self, head: ListNode) -> List[int]:
arr = []
while head != None:
arr.append(head.val)
head = head.next
l, r = 0, len(arr) - 1
while l < r:
val = arr[l]
arr[l] = arr[r]
arr[r] = val
l = l + 1
r = r - 1
return arr
node = ListNode.build([1, 2, 3, 4])
print(node)
# @lc code=start
# Definition for singly-linked list.
# class ListNode:
# def __init__(self, val=0, next=None):
# self.val = val
# self.next = next
class Solution:
def sortList(self, head: ListNode) -> ListNode:
nodes = []
node = head
while node:
nodes.append(node)
node = node.next
nodes.sort() # 用排序算法控制在O(n log n)
res = None
head = None
for node in nodes:
node.next = None
if head == None:
head = node
res = node
else:
res.next = node
res = res.next
return head
# @lc code=end
print(Solution().sortList(ListNode.build([4, 2, 1, 3])))
sys.path.append(os.path.dirname(os.path.dirname(os.path.realpath(__file__))))
from Tool.Python.ListNode import ListNode
class Solution:
def rotateRight(self, head: ListNode, k: int) -> ListNode:
if head == None:
return head
prevewNode = head
count = 1
while prevewNode.next != None:
prevewNode = prevewNode.next
count = count + 1
prevewNode.next = head
node = head
retainCount = count - k % count
while retainCount > 0:
prevewNode = node
node = node.next
retainCount = retainCount - 1
head = node
prevewNode.next = None
return head
print(Solution().rotateRight(ListNode.build([1, 2, 3, 4, 5]), 1))
print(Solution().rotateRight(ListNode.build([0, 1, 2]), 3))
print(Solution().rotateRight(ListNode.build([1, 2]), 2))
# print(Solution().rotateRight(None, 0))
if l1:
stack1.append(l1.val)
l1 = l1.next
if l2:
stack2.append(l2.val)
l2 = l2.next
r = ListNode(val=0)
while True:
if len(stack1) > 0:
r.val += stack1.pop()
if len(stack2) > 0:
r.val += stack2.pop()
if len(stack1) == 0 and len(stack2) == 0:
if r.val > 9:
r.val -= 10
r = ListNode(val=1, next=r)
break
else:
if r.val > 9:
r.val -= 10
r = ListNode(val=1, next=r)
else:
r = ListNode(val=0, next=r)
return r
# @lc code=end
print(Solution().addTwoNumbers(ListNode.build([7, 2, 4, 3]),
ListNode.build([5, 6, 4])))
class Solution:
def reverseKGroup(self, head: ListNode, k: int) -> ListNode:
root, pre_node = None, ListNode()
l_node = head
r_node = head
count = 0
while r_node != None:
if count < k - 1:
r_node = r_node.next
count = count + 1
else:
pre_node.next, pre_node_next, r_node_next = r_node, l_node, r_node.next
while l_node != r_node:
node = l_node
l_node = l_node.next
node.next = None
node.next = r_node.next
r_node.next = node
if root == None:
root = pre_node.next
pre_node = pre_node_next
l_node, r_node = r_node_next, r_node_next
count = 0
return root
# @lc code=end
print(Solution().reverseKGroup(ListNode.build([1, 2, 3, 4, 5]), 1))
import sys
import os
sys.path.append(os.path.dirname(os.path.dirname(os.path.realpath(__file__))))
from Tool.Python.ListNode import ListNode
class Solution:
def getKthFromEnd(self, head: ListNode, k: int) -> ListNode:
leftNode, rightNode = head, head
while k > 1:
if rightNode.next == None:
return None
else:
k -= 1
rightNode = rightNode.next
while rightNode.next:
leftNode = leftNode.next
rightNode = rightNode.next
return leftNode
print(Solution().getKthFromEnd(ListNode.build([1]), 1))
# def __init__(self, val=0, next=None):
# self.val = val
# self.next = next
class Solution:
def reorderList(self, head: ListNode) -> None:
"""
Do not return anything, modify head in-place instead.
"""
nodes, node = [], head
while node:
nodes.append(node)
node = node.next
left, right, direction = 0, len(nodes) - 1, 0
while left < right:
l_node = nodes[left]
r_node = nodes[right]
direction += 1
if direction % 2 == 1:
l_node.next = r_node
left += 1
else:
r_node.next = l_node
right -= 1
if left == right:
nodes[left].next = None
return head
# @lc code=end
print(Solution().reorderList(ListNode.build([1, 2, 3, 4, 5])))
node, isDuplicate = head, False
while node != None and node.next != None:
if node.val != node.next.val:
if isDuplicate == False:
if _headNode == None:
_head = ListNode(node.val)
_headNode = _head
else:
_headNode.next = ListNode(node.val)
_headNode = _headNode.next
node, isDuplicate = node.next, False
else:
node, isDuplicate = node.next, True
if isDuplicate == False:
if _head == None:
_head = node
if _headNode == None:
_headNode = node
else:
_headNode.next = node
_headNode = _headNode.next
pass
return _head
# @lc code=end
print(Solution().deleteDuplicates(None))
print(Solution().deleteDuplicates(ListNode.build([1, 2, 2])))
print(Solution().deleteDuplicates(ListNode("1->2->3->3->4->4->5".split("->"))))
print(Solution().deleteDuplicates(ListNode("1->1->1->2->3".split("->"))))
class Solution:
def partition(self, head: ListNode, x: int) -> ListNode:
pre_left, left, right = None, head, head
while right and right.next:
right = right.next
head, foot = None, None
while left != right:
leftNext = left.next
if left.val >= x:
left.next = None
if foot == None:
right.next = left
foot = left
right = right.next
else:
foot.next = left
foot = foot.next
if pre_left != None:
pre_left.next = leftNext
else:
pre_left = left
if head == None:
head = left
left = leftNext
if head == None:
head = left
return head
# @lc code=end
print(Solution().partition(ListNode.build([1,2]),3))
# # Definition for singly-linked list.
# class ListNode:
# def __init__(self, x):
# self.val = x
# self.next = None
#
# class Solution:
# def mergeKLists(self, lists: [ListNode]) -> ListNode:
# import heapq
# dummy = ListNode(0)
# p = dummy
# head = []
# for i in range(len(lists)):
# if lists[i] :
# heapq.heappush(head, (lists[i].val, i))
# lists[i] = lists[i].next
# while head:
# val, idx = heapq.heappop(head)
# p.next = ListNode(val)
# p = p.next
# if lists[idx]:
# heapq.heappush(head, (lists[idx].val, idx))
# lists[idx] = lists[idx].next
# return dummy.next
# Solution().mergeKLists([[1], [1,3,4], [2,6]])
# Solution().mergeKLists([ListNode.build([1]), ListNode.build([1,3,4]), ListNode.build([2,6])])
Solution().mergeKLists(
[ListNode.build([]),
ListNode.build([1, 3, 4]),
ListNode.build([2, 6])])
while True:
if index == m:
if pre_node:
pre_node.next = None
swap_pre_node, swap_node, swap_index = None, node, index
while swap_node and swap_index <= n:
next_node = swap_node.next
next_pre_node = swap_node
next_pre_node.next = None
if swap_pre_node:
swap_node.next = swap_pre_node
swap_pre_node = next_pre_node
swap_node = next_node
swap_index += 1
if swap_node:
node.next = swap_node
if pre_node:
pre_node.next = swap_pre_node
if not pre_node:
head = swap_pre_node
break
index += 1
pre_node = node
node = node.next
return head
# @lc code=end
print(Solution().reverseBetween(ListNode.build([1, 2, 3, 4, 5]), 1, 8))
# self.next = next
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, val=0, left=None, right=None):
# self.val = val
# self.left = left
# self.right = right
class Solution:
def sortedListToBST(self, head: ListNode) -> TreeNode:
def sortedArrToBST(arr: []) -> TreeNode:
if len(arr) == 0:
return None
midIndex = len(arr) // 2
midVal = arr[midIndex]
leftVals = arr[:midIndex]
rightVals = arr[midIndex + 1:]
return TreeNode(midVal,
left=sortedArrToBST(leftVals),
right=sortedArrToBST(rightVals))
vals = []
while head:
vals.append(head.val)
head = head.next
return sortedArrToBST(vals)
# @lc code=end
head = ListNode.build([-10, -3, 0, 5, 9])
ans = Solution().sortedListToBST(head)
print(ans)