Description: A stack is a data structure that follows the Last In, First Out (LIFO) principle. This means that the last element added to the stack is the first one to be removed. Stacks are fundamental in computer science and are used in various applications, from memory management to algorithm implementation. They can be visualized as a collection of elements stacked on top of each other, where only the top element can be accessed. The basic operations of a stack include ‘push’, which adds an element to the top, and ‘pop’, which removes the top element. Additionally, one can check the top element without removing it using the ‘peek’ operation. Stacks are particularly useful in situations where context tracking is required, such as in function execution and handling recursive calls. Their simplicity and efficiency make them an essential tool in programming and algorithm design.
Uses: Stacks are used in various computer applications, such as memory management in programming languages, tracking function calls, and implementing algorithms like depth-first traversal in graphs. They are also essential in evaluating mathematical expressions and implementing undo/redo functionality in software applications.
Examples: A practical example of a stack is the undo function in text editors, where each action is stacked and can be reverted by removing the most recent action. Another example is the use of stacks in evaluating arithmetic expressions in postfix notation.
