Uebungsaufgaben/Semester2/Vorlesung2part2.java

package Semester2;

public class Vorlesung2part2<T> {
    private Object[] myArray;
    private int numberOfElements;
    private int maxSize;


    public static void main(String[] args) {
        Vorlesung2part2 testObjekt = new Vorlesung2part2<>();
        for (int i = 0; i < 300; i++) {
            if (i < 150) {
                testObjekt.add(new Vorlesung2part2<>());
            } else {
                testObjekt.get();
            }

            System.out.println(i);
        }
    }


    public Vorlesung2part2() {
        this.numberOfElements = 0;
        this.maxSize = 100;
        myArray = new Object[this.maxSize];
    }


    public void add(T t) {
        this.myArray[this.numberOfElements] = t;
        this.numberOfElements++;
        this.check();
    }


    public T get() {
        T retValue = (T) this.myArray[0];
        for (int i=0; i<this.numberOfElements; i++) {
            this.myArray[i] = this.myArray[i+1];
        }
        this.numberOfElements--;
        this.check();
        return retValue;
    }


    public int size() {
        return this.numberOfElements;
    }


    public void check() {
        Object[] temp = myArray;
        if ((float)this.numberOfElements/(float)this.maxSize > 0.8) {
            this.maxSize *= 2;
            temp = myArray;
        } else if (((float)this.numberOfElements/(float)this.maxSize < 0.2) && (this.maxSize >= 40)) {
            this.maxSize /= 2;
            temp = myArray;
        } else {
            return;
        }

        myArray = new Object[this.maxSize];
        for (int i = 0; i < this.numberOfElements; i++) {
            myArray[i] = temp[i];
            System.out.println(myArray[i]);
        }

        System.out.println("New size: " + this.maxSize);
    }
}