Implementation of Stack Using Linked List and List – Code Snippet

The stack is a data structure. To implement a stack data structure, we can use both linked list or array. Below are examples of both types of implementation.

Using Linked List

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

	def __init__(self):
		self.head = None
	
	def push(self, data):
		new_node = Node(data)
		new_node.next = self.head
		self.head = new_node
		
	def pop(self):
		if self.head == None:
			return 'Stack is empty'

		self.head = self.head.next
	
	def peek(self):
		if self.head == None:
			return 'Stack is empty'

		return self.head.data
	
	def is_empty(self):
		return self.head == None
	
stack = Stack()

print(stack.is_empty())

stack.push(1)
stack.push(3)
stack.push(5)
stack.push(7)
stack.push(9)

print(stack.peek())
stack.pop()
print(stack.peek())

print(stack.is_empty())

Using Python List

lst = []

# push
lst.append(1)
lst.append(2)
lst.append(3)
lst.append(4)

print(lst) # [1, 2, 3, 4]

# pop
lst.pop()

print(lst) # [1, 2, 3]

# is_empty
print(len(lst) == 0) # False

Tags: CodeLinked ListListStack