Question

I implemented a queue and various operations as shown below. Is there any other easy method to implement queue(Circular Queue) in Java?? Which is the easiest way to implement queue in java??

import java.io.*;
import java.util.*;

public class QueueImplement {

    LinkedList<Integer> list;
    String str;
    int num;

    public static void main(String[] args) {
        QueueImplement q = new QueueImplement();
    }

    public QueueImplement() {
        try {
            list = new LinkedList<Integer>();
            InputStreamReader ir = new InputStreamReader(System.in);
            BufferedReader bf = new BufferedReader(ir);
            System.out.println("Enter number of elements : ");
            str = bf.readLine();
            if ((num = Integer.parseInt(str)) == 0) {
                System.out.println("You have entered either zero/null.");
                System.exit(0);
            } else {
                System.out.println("Enter elements : ");
                for (int i = 0; i < num; i++) {
                    str = bf.readLine();
                    int n = Integer.parseInt(str);
                    list.add(n);
                }
            }
            System.out.println("First element :" + list.removeFirst());
            System.out.println("Last element :" + list.removeLast());
            System.out.println("Rest elements in the list :");
            while (!list.isEmpty()) {
                System.out.print(list.remove() + "\t");
            }
        } catch (IOException e) {
            System.out.println(e.getMessage() + " is not a legal entry.");
            System.exit(0);
        }
    }
}

Answer 1

LinkedList you used already implements Queue interface.