Error in Double hashing for linear probing

[qiuhaha]

Your first and secondary hash function are like this:

protected int hash(Key key) 
{
    int hash = key.hashCode() & 0x7fffffff;
    if (lgM < 26) 
        hash = hash % PRIMES[lgM + 5];
    return hash % size;
}
protected int secondaryHash(Key key) 
{
    int hash2 = (key.hashCode() % size) & 0x7fffffff;
    hash2 = hash2 != 0 ? hash2 : size + 1;
    return hash2;
}

The problem here is that the keys with the same hashCode values still end up with the same exact probe sequence. You should compute a new hashCode for the secondary hash function.

[reneargento]

The issue is that ideally the hash functions should generate different hashes, right?
If that is the case, I updated the exercise here: ffeb38d
Thanks for the suggestion!