Medium
Print Immutable Linked List in Reverse — Python
Full explanation · Time O(n) · Space O(sqrt(n))
# Time: O(n)
# Space: O(sqrt(n))
import math
class Solution(object):
def printLinkedListInReverse(self, head):
"""
:type head: ImmutableListNode
:rtype: None
"""
def print_nodes(head, count):
nodes = []
while head and len(nodes) != count:
nodes.append(head)
head = head.getNext()
for node in reversed(nodes):
node.printValue()
count = 0
curr = head
while curr:
curr = curr.getNext()
count += 1
bucket_count = int(math.ceil(count**0.5))
buckets = []
count = 0
curr = head
while curr:
if count % bucket_count == 0:
buckets.append(curr)
curr = curr.getNext()
count += 1
for node in reversed(buckets):
print_nodes(node, bucket_count)
# Time: O(n)
# Space: O(n)
class Solution2(object):
def printLinkedListInReverse(self, head):
"""
:type head: ImmutableListNode
:rtype: None
"""
nodes = []
while head:
nodes.append(head)
head = head.getNext()
for node in reversed(nodes):
node.printValue()
# Time: O(n^2)
# Space: O(1)
class Solution3(object):
def printLinkedListInReverse(self, head):
"""
:type head: ImmutableListNode
:rtype: None
"""
tail = None
while head != tail:
curr = head
while curr.getNext() != tail:
curr = curr.getNext()
curr.printValue()
tail = curr