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#!/usr/bin/env python
# -*- coding: utf-8 -*-
class Node:
def __init__(self, x):
self.val = x
self.next = None
def reorderList(head):
# Find the middle of the linked list
slow = fast = head
while fast and fast.next:
slow = slow.next
fast = fast.next.next
# Reverse the second half of the linked list
prev = None
while slow:
next_node = slow.next
slow.next = prev
prev = slow
slow = next_node
# Merge the first half and the reversed second half
first_half = head
second_half = prev
while second_half.next:
first_half.next, first_half = second_half, first_half.next
second_half.next, second_half = first_half, second_half.next
return head
# Test the function
head = Node(1)
head.next = Node(2)
head.next.next = Node(3)
head.next.next.next = Node(4)
reordered_list = reorderList(head)
node = reordered_list
while node:
print(node.val, end=" ")
node = node.next
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