What is the time complexity of enqueue operation in a queue?

Java MCQ: What is the time complexity of enqueue operation in a queue?

Answer:

Explanation:

The time complexity of the enqueue operation in a queue is O(1), meaning that the operation is performed in constant time, regardless of the number of elements in the queue. This efficiency is achieved because the enqueue operation typically involves adding an element to the rear of the queue, which can be done in constant time without the need to traverse or modify other elements in the queue.

This O(1) time complexity makes queues suitable for applications where frequent addition and removal of elements are required, such as in task scheduling, request handling, and breadth-first search (BFS) algorithms. The constant time for enqueue operations ensures that the performance of the queue remains consistent, even as the number of elements grows.

Here’s an example of an enqueue operation in Java:

import java.util.LinkedList;
import java.util.Queue;

public class Main {
    public static void main(String[] args) {
        Queue<Integer> queue = new LinkedList<>();
        queue.add(10); // Enqueue operation
        queue.add(20);
        queue.add(30);
        System.out.println(queue); // Outputs: [10, 20, 30]
    }
}

In this example, each enqueue operation is executed in constant time, demonstrating the O(1) complexity. This efficiency is one of the key reasons why queues are commonly used in scenarios where elements need to be processed in the order they arrive, and quick insertion is necessary.

Reference links:

https://www.javaguides.net/p/java-queue-tutorial.html