Programa de Python para reorganizar una lista vinculada de modo que todos los Nodes en posiciones pares e impares estén juntos

Python3

# Python3 program to rearrange a
# linked list in such a way that
# all odd positioned node are stored
# before all even positioned nodes
 
# Linked List Node
class Node:
    def __init__(self, d):
        self.data = d
        self.next = None
 
class LinkedList:
    def __init__(self):
        self.head = None
         
    # A utility function to create
    # a new node
    def newNode(self, key):
        temp = Node(key)
        self.next = None
        return temp
 
    # Rearranges given linked list
    # such that all even positioned
    # nodes are before odd positioned.
    # Returns new head of linked List.
    def rearrangeEvenOdd(self, head):
         
        # Corner case
        if (self.head == None):
            return None
 
        # Initialize first nodes of
        # even and odd lists
        odd = self.head
        even = self.head.next
 
        # Remember the first node of
        # even list so that we can
        # connect the even list at the
        # end of odd list.
        evenFirst = even
 
        while (1 == 1):
             
            # If there are no more nodes,
            # then connect first node of even
            # list to the last node of odd list
            if (odd == None or even == None or
               (even.next) == None):
                odd.next = evenFirst
                break
 
            # Connecting odd nodes
            odd.next = even.next
            odd = even.next
 
            # If there are NO more even nodes
            # after current odd.
            if (odd.next == None):
                even.next = None
                odd.next = evenFirst
                break
 
            # Connecting even nodes
            even.next = odd.next
            even = odd.next
        return head
 
    # A utility function to print a
    # linked list
    def printlist(self, node):
        while (node != None):
            print(node.data, end = "")
            print("->", end = "")
            node = node.next
        print ("NULL")
         
    # Function to insert a new node
    # at the beginning
    def push(self, new_data):
        new_node = Node(new_data)
        new_node.next = self.head
        self.head = new_node
 
# Driver code
ll = LinkedList()
ll.push(5)
ll.push(4)
ll.push(3)
ll.push(2)
ll.push(1)
print ("Given Linked List")
ll.printlist(ll.head)
 
start = ll.rearrangeEvenOdd(ll.head)
 
print ("Modified Linked List")
ll.printlist(start)
# This code is contributed by Prerna Saini