When it is required to print the middle most element of a linked list, a method named ‘print_middle_val’ is defined. This method takes the linked list as a parameter and gets the middle most element.
Below is a demonstration for the same −
Example
class Node:
def __init__(self, data):
self.data = data
self.next = None
class LinkedList_structure:
def __init__(self):
self.head = None
self.last_node = None
def add_vals(self, data):
if self.last_node is None:
self.head = Node(data)
self.last_node = self.head
else:
self.last_node.next = Node(data)
self.last_node = self.last_node.next
def print_middle_val(my_list):
curr = my_list.head
my_len = 0
while curr:
curr = curr.next
my_len = my_len + 1
curr = my_list.head
for i in range((my_len - 1)//2):
curr = curr.next
if curr:
if my_len % 2 == 0:
print('The two middle elements are {} and {}'.format(curr.data, curr.next.data))
else:
print('The middle-most element is {}.'.format(curr.data))
else:
print('The list is empty')
my_instance = LinkedList_structure()
my_list = input('Enter the elements of the linked list... ').split()
for elem in my_list:
my_instance.add_vals(int(elem))
print_middle_val(my_instance)Output
Enter the elements of the linked list... 56 23 78 99 34 11 The two middle elements are 78 and 99
Explanation
The ‘Node’ class is created.
Another ‘LinkedList_structure’ class with required attributes is created.
It has an ‘init’ function that is used to initialize the first element, i.e the ‘head’ to ‘None’.
A method named ‘add_vals’ is defined, that helps add a value to the stack.
Another method named ‘print_middle_val’ is defined, that helps display the middle value of the linked list on the console.
An instance of the ‘LinkedList_structure’ is created.
Elements are added to the linked list.
The elements are displayed on the console.
The ‘print_middle_val’ method is called on this linked list.
The output is displayed on the console.