What are the main tasks of using a stack data structure?

A stack is a data structure that operates on the LIFO (Last In, First Out) principle, meaning the last added element is retrieved first.

Main tasks of using a stack:

• Managing function calls and returns (call stack).
• Processing expressions and calculations (e.g., converting infix notation to postfix).
• Undo operations in applications.
• Parsing and checking the correctness of brackets in expressions.

Example of using a stack in C#:

Stack<int> stack = new Stack<int>();
stack.Push(1);
stack.Push(2);
int top = stack.Pop(); // top = 2

A stack is useful where the order of processing elements in the reverse order of their addition is important.