Algorithm Design Questions Medium
The main difference between a stack and a queue lies in their fundamental principles of operation and the order in which elements are accessed.
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. It can be visualized as a stack of plates, where you can only access the topmost plate. Elements are added and removed from the same end, known as the top of the stack. This operation is commonly referred to as push (addition) and pop (removal). Stacks are typically used in scenarios where the order of processing is important, such as function calls, undo/redo operations, or backtracking algorithms.
On the other hand, a queue is a data structure that follows the First-In-First-Out (FIFO) principle. This means that the first element added to the queue is the first one to be removed. It can be visualized as a line of people waiting for a service, where the person who arrived first is served first. Elements are added at one end, known as the rear or back of the queue, and removed from the other end, known as the front or head of the queue. This operation is commonly referred to as enqueue (addition) and dequeue (removal). Queues are typically used in scenarios where the order of arrival is important, such as task scheduling, message passing, or breadth-first search algorithms.
In summary, the key difference between a stack and a queue is the order in which elements are accessed and removed. A stack follows the LIFO principle, while a queue follows the FIFO principle.