arraystackqueue

import java.util.Arrays;

public class ArrayStackQueue<T> {
    T[] asq;
    int m;
    int top, front, rear;

    @SuppressWarnings("unchecked")
    public ArrayStackQueue(int m) {
        asq = (T[]) new Object[2 * m];

        this.m = m;
        top = -1;
        front = 2 * m;
        rear = 2 * m;

        for (int i = 0; i < asq.length; i++)
            asq[i] = null;
    }

    public void push(T element) {
        if (top == m - 1)
            throw new IllegalArgumentException("Stack is full!");

        asq[++top] = element;
    }

    public void insert(T element) {
        if (rear == m)
            throw new IllegalArgumentException("Queue is full!");

        if (rear == 2 * m) {
            front = 2 * m - 1;
        }

        rear--;
        asq[rear] = element;
    }

    public T remove() {
        if (rear == 2 * m)
            throw new IllegalArgumentException("Queue is Empty");

        T x = asq[front];
        asq[front] = null;
        if (front == rear) {
            front = 2 * m;
            rear = 2 * m;
        } else {
            front = front - 1;
        }
        return x;
    }

    public static void main(String[] args) {
        ArrayStackQueue<Integer> asq = new ArrayStackQueue<>(3);
        asq.push(10);
        asq.push(20);
        asq.push(30);
        System.out.println(Arrays.toString(asq.asq));
        asq.insert(90);
        asq.insert(100);
        asq.insert(120);
        System.out.println(Arrays.toString(asq.asq));
        asq.remove();
        asq.remove();
        asq.remove();
        System.out.println(Arrays.toString(asq.asq));

    }
}