while slow and fast:
slow = slow.next
fast = fast.next
return slow
def removeKthFromEnd(self, head, k):
fast = head
slow = head
pre = None
i = k
while i > 0:
fast = fast.next
i = i-1
if fast==None:
head = slow.next
return head
while fast!=None:
pre = slow
slow = slow.next
fast = fast.next
pre.next = slow.next
slow.next = None
return head
head = construct_List_I([1, 2, 3, 4, 5])
solu = Solution()
print(solu.findKthFromEnd(head, 5).val)
print(travel_List(head))
while cur1 and cur2:
if cur1.val <= cur2.val:
cur.next = cur1
cur = cur1
cur1 = cur1.next
else:
cur.next = cur2
cur = cur2
cur2 = cur2.next
while cur1:
cur.next = cur1
cur = cur1
cur1 = cur1.next
while cur2:
cur.next = cur2
cur = cur2
cur2 = cur2.next
cur.next = None
return head
from utils import construct_List_I, travel_List
l1 = construct_List_I([1, 2, 4])
l2 = construct_List_I([1, 3, 4])
solu = Solution()
l3 = solu.mergeTwoLists(l1, l2)
print(travel_List(l3))
while i < m:
if cur == None:
return root
pre_head = cur
cur = cur.next
i += 1
# pre_head为第m-1个节点，cur为第m个节点,此时i=m
reverse_start = cur
reverse_end = cur
cur = cur.next
while i < n:
next = cur.next
cur.next = reverse_start
reverse_start = cur
cur = next
i += 1
reverse_end.next = cur
if pre_head == None:
return reverse_start
else:
pre_head.next = reverse_start
return root
root = construct_List_I([1, 2, 3, 4, 5, 6])
solu = Solution()
root = solu.reverseList_II(root, 1, 6)
print(solu.travelList(root))
class Solution:
def deleteNode(self, cur):
# 题目237
cur.val = cur.next.val
cur.next = cur.next.next
def removeElements(self, root, val):
# 题目203
cur = root
pre = None
while cur != None:
if cur.val == val:
if pre == None:
root = cur.next
cur = cur.next
else:
pre.next = cur.next
cur = cur.next
else:
pre = cur
cur = cur.next
return root
head = construct_List_I([1, 2, 1, 4, 1])
solu = Solution()
head = solu.removeElements(head, 1)
print(travel_List(head))
else:
pre = cur
cur = cur.next
return root
def deleteDuplicates(self, head):
'''
第一个重复点保留，后面的重复点都删除
输入: 1->1->2->3->3
输出: 1->2->3
'''
pre = None
cur = head
while cur:
if pre and pre.val == cur.val:
while pre and cur:
if pre.val == cur.val:
cur = cur.next
else:
break
pre.next = cur
else:
pre = cur
cur = cur.next
return head
slou = Solution()
root = construct_List_I([2, 2, 4, 4, 4])
root = slou.deleteDuplicates(root)
print(travel_List(root))