DemoQueue3 - SpecialQueue.java

public class SpecialQueue<ELEMENT> {
    private ELEMENT[] data;
    private int head;
    private int tail;
    private int count;

    public SpecialQueue() {
        this(10);
    }

    public SpecialQueue(int capacity) {
        this.data = (ELEMENT[]) new Object[capacity];
        this.head = 0;
        this.tail = 0;
        this.count = 0;
    }

    // Equivalent to Count property in C#
    public int size() {
        return this.count;
    }

    private int Next(int position) {
        return (++position >= this.data.length)? 0: position;
    }

    // Equivalent to Enqueue method in C#
    public void add(ELEMENT element) {
        if (this.count >= this.data.length) {
            throw new RuntimeException("La cola está llena...");
        }
        this.data[this.tail] = element;
        this.tail = this.Next(this.tail);
        ++this.count;
    }

    // Equivalent to Dequeue method in C#
    public ELEMENT remove() {
        if (this.count <= 0) {
            throw new RuntimeException("La cola está vacía...");
        }
        ELEMENT temp = this.data[this.head];
        this.head = this.Next(this.head);
        --this.count;
        return temp;
    }

    public ELEMENT[] toArray() {
        ELEMENT[] result =  (ELEMENT[]) new Object[this.size()];;
        for (int pos = this.head, c = 0; c < this.count; c++) {
            result[c] = this.data[pos];
            pos = this.Next(pos);
        }
        return result;
    }

    public SpecialQueue<ELEMENT> join(SpecialQueue<ELEMENT> other) {
        SpecialQueue<ELEMENT> result =
        new SpecialQueue<ELEMENT>((this.size() + other.size()) * 2);

        ELEMENT[] data = this.toArray();
        for (ELEMENT e : data) {
            result.add(e);
        }

        data = other.toArray();
        for (ELEMENT e : data) {
            result.add(e);
        }

        return result;
    }
}