A linear queue is a type of data structure where the data elements are arranged in a sequential manner, and the addition of new elements is done from one end and the deletion of elements is performed from the other end. It follows the FIFO (First In First Out) principle.
An example of a linear queue is a queue of customers waiting in a line to pay for their groceries at a supermarket. The first customer to arrive at the checkout line is the first customer to be served, and the last customer to arrive will be the last to be served. If a new customer arrives, they must stand at the end of the queue, and the customer at the front of the queue will be serviced and removed from the queue first. This process will continue until all the customers in the queue have been served.
Linear queue is a type of collection that follows the First-In-First-Out (FIFO) principle, where the first element added to the queue gets accessed first.
It uses an array data structure to store the elements in a sequential manner, and two pointers known as front and rear, to keep track of the elements.
The front pointer points to the first element in the queue, while the rear pointer points to the last element that was added.
Initially, both pointers are set to -1, indicating that the queue is empty.
When an element is added to the queue, it is inserted at the rear end of the queue using the rear pointer, and the rear pointer is incremented by 1.
When an element is removed from the queue, the front pointer is incremented by 1, and the corresponding element is deleted from the front end of the queue.
Linear queue has a fixed size, and once its capacity is reached, it is said to be full, and no more elements can be added to it.
One disadvantage of linear queue is that it suffers from the problem of overflow (when the queue is full) and underflow (when the queue is empty).
However, linear queue is a simple and efficient data structure that is widely used in computer programming for implementing various algorithms and applications.
What is a linear queue and how does it differ from other types of queues?
Answer: A linear queue is a collection of elements arranged in a linear order where insertion is done at one end and deletion is done at the other end. This differs from other types of queues such as circular queues, where the last element is connected to the first element, creating a circular structure.
How do you check if a linear queue is empty or full?
Answer: To check if a linear queue is empty, we can simply check if the front and rear pointers are equal. To check if a linear queue is full, we can compare the rear pointer with the maximum size limit of the queue element.
How do you implement a linear queue using an array in C++?
Answer: We can implement a linear queue using an array in C++ by defining a fixed-size array and two pointers, front and rear. The front pointer indicates the first element in the queue, and the rear pointer indicates the last element. An element is added to the queue by incrementing the rear pointer and placing the element at this position, and an element is removed by incrementing the front pointer.
How do you calculate the time complexity for inserting an element in a linear queue?
Answer: The time complexity for inserting an element in a linear queue is O(1) because we only need to increment the rear pointer and add the element to the end of the queue.
How can you prevent overflow and underflow in a linear queue?
Answer: To prevent overflow in a linear queue, we can check if the rear pointer is equal to the maximum size limit of the queue element before inserting an element. To prevent underflow, we can check if the front pointer is equal to the rear pointer before deleting an element.