Stacks

A stack is a fundamental data structure in computer science with a specific set of rules and behaviors. It follows the Last-In, First-Out (LIFO) principle, which means that the last item added to the stack is the first one to be removed. Here's a theoretical overview of stacks:

Components of a Stack:

• Elements: These are the individual data items stored in the stack.
• Top: This is the reference to the top element of the stack. It's the only element accessible for insertion or deletion.

Basic Operations on Stacks:

• Push: This operation adds an element to the top of the stack.
• Pop: This operation removes and returns the top element of the stack.
• Peek: This operation returns the top element without removing it.
• isEmpty: This operation checks whether the stack is empty.

Common Use Cases:

• Function Call Stack: In many programming languages, the function call stack is implemented using a stack data structure. It keeps track of function calls and their local variables.
• Expression Evaluation: Stacks can be used to evaluate expressions, including arithmetic expressions and parsing mathematical expressions.
• Backtracking: Stacks are used in algorithms involving backtracking, such as depth-first search (DFS) in graph traversal.