STACK
WHAT IS A STACK ??
A stack is a linear data structure that follows the LIFO (Last In First Out) principle
Last In First Out ???
Picture how pancakes are served.
After being stacked, we eat from the topmost pancake
Don't be like Dwight Schrute 😂
FIRST PANCAKE ON THE PLATE,
LAST PANCAKE TO GET OFF THE PLATE
The last element inserted is the first one to be removed
OTHER REAL LIFE EXAMPLES
Browser back button (history tracking)
Undo feature in text editors
BASIC OPERATIONS
Push ( )
Add an element to t he top of the stack
Pop ( )
Remove the top element for the stack
Peek / Top ( )
Retrieving the top element
Size ( )
Return the number of elements in the stack
isEmpty ( )
Check if stack is empty
REPRESENTATION OF STACK
ARRAYS
Fixed size, faster access.
LINKED LIST
Dynamic size, slower access, better memory utilization
TIME COMPLEXITY
O (1)
Pop ( ), Push ( ), Peek ( ), isEmpty ( )
SPACE COMPLEXITY
O (n)
Further Reading and Relevant Links
CODEBASICS: Stack - Data structures and Algorithm
USFCA: Stack (Array) Visualization
USFCA: Stack (Linked List) Visualization
Leetcode challenges on Stack? Here we gooooo
Thank you !!!!
