Data Structures Questions Long
A queue is a linear data structure that follows the First-In-First-Out (FIFO) principle. It is an ordered collection of elements where the addition of new elements takes place at one end called the rear, and the removal of existing elements occurs at the other end called the front. In simpler terms, a queue represents a line of elements where the element that enters first is the first one to leave.
On the other hand, a stack is also a linear data structure but follows the Last-In-First-Out (LIFO) principle. It is an ordered collection of elements where the addition of new elements and the removal of existing elements both take place at the same end called the top. In a stack, the element that enters last is the first one to leave.
The main difference between a queue and a stack lies in the order in which elements are added and removed. In a queue, the element that enters first is the first one to be removed, while in a stack, the element that enters last is the first one to be removed.
Another difference is the way elements are accessed. In a queue, elements can only be accessed from the front, which means that the element at the front is the only one that can be removed or examined. In contrast, in a stack, elements can only be accessed from the top, allowing for the removal or examination of the topmost element.
In terms of implementation, both queues and stacks can be implemented using arrays or linked lists. However, the operations performed on them differ. In a queue, the main operations are enqueue (adding an element to the rear) and dequeue (removing an element from the front). In a stack, the main operations are push (adding an element to the top) and pop (removing an element from the top).
To summarize, a queue and a stack are both linear data structures, but they differ in terms of the order in which elements are added and removed, the way elements are accessed, and the main operations performed on them.