public void quadraticHashInsert(int key)
    {
        //quadratic probing method
        if (!checkOpenSpace())//if no open spaces available
        {
            Console.WriteLine("table is at full capacity!");
            return;
        }

        if (Search(key))
        {
            Console.WriteLine("Key already exists!");
            return;
        }

        int j    = 0;
        int hash = HashTabQuadProb.hash(key);

        while (table[hash] != null)
        {
            j++;
            hash = mod((HashTabQuadProb.hash(key) + (j * j)), maxSize);
            if (table[hash] != null)
            {
                hash = mod((HashTabQuadProb.hash(key) + ((j * j) * -1)), maxSize);
            }
        }
        if (table[hash] == null)
        {
            table[hash] = new HashProbe(key, key);
            return;
        }
    }
    public bool Search(int key)
    {
        int j    = 0;
        int hash = HashTabQuadProb.hash(key);

        while (table[hash] != null && table[hash].getkey() != key)
        {
            j++;
            hash = mod((HashTabQuadProb.hash(key) + (j * j)), maxSize);
            if (table[hash] != null)
            {
                hash = mod((HashTabQuadProb.hash(key) + ((j * j) * -1)), maxSize);
            }
        }
        if (table[hash] == null)
        {
            return(false);
        }
        else
        {
            Console.WriteLine("Der Schlüssel " + key + " ist im folgenden hash gespeichert: " + hash);
            return(true);
        }
    }
    public bool Delete(int key)
    {
        int j    = 0;
        int hash = HashTabQuadProb.hash(key);

        while (table[hash] != null && table[hash].getkey() != key)
        {
            j++;
            hash = mod((HashTabQuadProb.hash(key) + (j * j)), maxSize);
            if (table[hash] != null)
            {
                hash = mod((HashTabQuadProb.hash(key) + ((j * j) * -1)), maxSize);
            }
        }
        if (table[hash] == null)
        {
            return(false);
        }
        else
        {
            table[hash] = null;
            return(true);
        }
    }