Python program that deletes a node from the beginning of a circular linked list:
class Node:
def __init__(self, data=None):
self.data = data
self.next = None
class CircularLinkedList:
def __init__(self):
self.head = None
def append(self, data):
if not self.head:
self.head = Node(data)
self.head.next = self.head
else:
current = self.head
while current.next != self.head:
current = current.next
new_node = Node(data)
current.next = new_node
new_node.next = self.head
def delete_at_start(self):
current = self.head
if self.head:
while current.next != self.head:
current = current.next
current.next = self.head.next
self.head = self.head.next
def display(self):
current = self.head
if self.head:
while current.next != self.head:
print(current.data)
current = current.next
print(current.data)
# create circular linked list
cll = CircularLinkedList()
# append some data to the list
cll.append(1)
cll.append(2)
cll.append(3)
# delete the first node
cll.delete_at_start()
# display the updated list
cll.display()
In this example, we first define a Node class with a constructor that initializes the data and next properties. The CircularLinkedList class is implemented using the Node class. The CircularLinkedList class has an append method that adds new data to the end of the linked list and a display method that prints the data of each node in the list.
The delete_at_start() method deletes the first node from the beginning of the circular linked list. It starts by initializing a current variable to the head of the linked list, then it iterates through the list until it reaches the last node. It then updates the next pointer of the last node to point to the second node, effectively cutting the first node out of the list. Finally, it updates the head of the linked list to point to the second node.
After calling the delete_at_start method, the updated list can be displayed using the display method.
Please note that this implementation assumes the list is not empty and if the list is empty it will raise an Exception.