Stacks

Stacks A stack is a LIFO (Last-In, First-Out) data structure. This means that the top element is the one that was added first. Think of a stack as a stack o...

Stacks

A stack is a LIFO (Last-In, First-Out) data structure. This means that the top element is the one that was added first. Think of a stack as a stack of plates: you can only add or remove plates from the top.

Basic operations:

Push (add top element): Push an element onto the top of the stack.
Pop (remove top element): Remove and return the top element from the stack.
Top (return top element): Return the top element without removing it.

Applications of stacks:

Reverse order processing: You can use a stack to process a sequence of elements in reverse order.
Solving problems: Stacks can be used to solve problems involving towers, undo/redo operations, and more.
Undo/redo systems: Stacks are often used in undo/redo systems to keep track of changes made to a program.

Example:

Let's say we have a stack with the following elements:

Push (a)

Push (b)

Push (c)

After pushing these elements onto the stack, we can perform the following operations:

Pop (top element): a
Push (d): This element will be added to the top of the stack.
Pop (top element): b
Push (e): This element will be added to the top of the stack.
Pop (top element): c

This process demonstrates the LIFO principle of a stack.