class Queue:
def __init__(self):
self.s = SinglyLinkedList()
def enqueue(self, value):
self.s.insert_last(value)
def dequeue(self):
return self.s.delete_start()
def print_queue(self):
self.s.print_linklist()
def is_empty(self):
if self.s.size == 0:
return True
return False
def __len__(self):
return self.s.size
def peek(self):
if self.is_empty():
print("Queue is empty")
return
return self.s.head.data
class Stack:
def __init__(self):
self.s = SinglyLinkedList()
def push(self, value):
self.s.insert_start(value)
def pop(self):
return self.s.delete_start()
def print_stack(self):
self.s.print_linklist()
def is_empty(self):
if self.s.size == 0:
return True
return False
def __len__(self):
return self.s.size
def peek(self):
if self.is_empty():
print("Stack is empty")
return
return self.s.head.data
