# Python Program to Find the Largest Element in a Doubly Linked List

When it is required to find the largest element in a doubly linked list, a method to add elements to the doubly linked list, a method to print the elements of the doubly linked list, and a method to find the largest element in a doubly linked list are defined.

Below is a demonstration for the same −

## Example

Live Demo

class Node:
def __init__(self, data):
self.data = data
self.next = None
self.prev = None

def __init__(self):
self.first = None
self.last = None

self.insert_at_end(Node(data))

def insert_at_end(self, newNode):
if self.last is None:
self.last = newNode
self.first = newNode
else:
newNode.prev = self.last
self.last.next = newNode
self.last = newNode

def find_largest_val(my_list):
if my_list.first is None:
return None
largest_val = my_list.first.data
curr = my_list.first.next
while curr:
if curr.data > largest_val:
largest_val = curr.data
curr = curr.next
return largest_val

my_list = input('Enter the elements in the doubly linked list ').split()
for elem in my_list:

largest_val = find_largest_val(my_instance)
if largest_val:
print('The largest element is {}.'.format(largest_val))
else:
print('The list is empty.')

## Output

Enter the elements in the doubly linked list 45 12 67 89 234 567 888 44 999
The largest element is 999.

## Explanation

• The ‘Node’ class is created.

• Another ‘DoublyLinkedList_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 ‘insert_at_end’ is defined, that helps add a value to the end of the doubly linked list.

• Another method named ‘find_largest_val’ is defined, that helps find the largest value in the entire doubly linked list.

• An instance of the ‘DoublyLinkedList_structure’ is created.

• The ‘find_largest_val’ method is called on this doubly linked list.

• The output is displayed on the console.