"""
:type head: ListNode
:rtype: ListNode
"""
if not head:
return None
p = head
pre = None
while p.next:
q = p.next
if not pre:
p.next, q.next = q.next, p
head = q
else:
pre.next, p.next, q.next = q, q.next, p
pre = p
if p.next:
p = p.next
else:
break
return head
from Leetcode_medium.linkedlist.linkedlist import LinkedList
s = Solution()
x = [1, 2]
L = LinkedList(x)
L.display()
L.display(s.swapPairs(L.root))
def __init__(self, x):
self.val = x
self.next = None
class Solution(object):
def deleteDuplicates(self, head):
"""
:type head: ListNode
:rtype: ListNode
"""
root = pre = ListNode(0)
root.next = head
while head and head.next:
if head.val == head.next.val:
while head and head.next and head.val == head.next.val:
head = head.next
head = head.next
pre.next = head
else:
pre = pre.next
head = head.next
return root.next
from Leetcode_medium.linkedlist.linkedlist import LinkedList
s = Solution()
x = [1, 1, 2,2]
L = LinkedList(x)
L.display()
L.display(s.deleteDuplicates(L.root))
if m == n:
return head
count = 1
p = q = head
res = []
while count <= n:
if count < m:
p = p.next
else:
res.append(q.val)
if count < n:
q = q.next
if count == n:
print(res)
for i in range(len(res)):
p.val = res[-i - 1]
p = p.next
count += 1
return head
from Leetcode_medium.linkedlist.linkedlist import LinkedList
s = Solution()
x = [1, 2, 3, 4, 5]
m = 2
n = 5
L = LinkedList(x)
L.display()
L.display(s.reverseBetween(L.root, m, n))
# Definition for singly-linked list.
# class ListNode(object):
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution(object):
def rotateRight(self, head, k):
"""
:type head: ListNode
:type k: int
:rtype: ListNode
"""
from Leetcode_medium.linkedlist.linkedlist import LinkedList
s = Solution()
x = [1, None]
n = 2
L = LinkedList(x)
L.display()
L.display(s.rotateRight(L.root, n))
class Solution(object):
def partition(self, head, x):
"""
:type head: ListNode
:type x: int
:rtype: ListNode
"""
d1 = large = ListNode(-1)
d2 = small = ListNode(0)
cur = head
while cur:
if cur.val < x:
small.next = cur
small = small.next
else:
large.next = cur
large = large.next
cur = cur.next
large.next = None
small.next = d1.next
return d2.next
from Leetcode_medium.linkedlist.linkedlist import LinkedList
s = Solution()
x = [1, 4, 3, 2, 5, 2]
n = 3
L = LinkedList(x)
L.display()
L.display(s.partition(L.root, n))
class Solution(object):
def removeNthFromEnd(self, head, n):
"""
:type head: ListNode
:type n: int
:rtype: ListNode
"""
if n == 0:
return head
p = q = head
while p.next:
if n > 0:
n -= 1
else:
q = q.next
p = p.next
if n:
head = head.next
else:
q.next = q.next.next
return head
from Leetcode_medium.linkedlist.linkedlist import LinkedList
s = Solution()
x = [1,2,3,4,5]
n = 5
L = LinkedList(x)
L.display()
L.display(s.removeNthFromEnd(L.root, n))
# class RandomListNode(object):
# def __init__(self, x):
# self.label = x
# self.next = None
# self.random = None
class ListNode(object):
def __init__(self, x):
self.val = x
self.next = None
class Solution(object):
def copyRandomList(self, head):
"""
:type head: RandomListNode
:rtype: RandomListNode
"""
if head:
p = ListNode(head.val)
if head.next:
p.next = self.copyRandomList(head.next)
return p
return head
from Leetcode_medium.linkedlist.linkedlist import LinkedList
s = Solution()
x = [1,2,3,4,5]
L = LinkedList(x)
L.display()
L.display(s.copyRandomList(L.root))