[-1234, 10, -1234, 1, -1234, 10, -1234, 1]

HashMap<Integer,Integer> hm = new HashMap<Integer,Integer>();
    //String hashes are keys, # occurrences are values

    for (int i = 0; i < str.length; i++) //two loops to loop through every subarray
        for (int j = i; j < str.length; j++) {
            int hash = 1;
            for (int k = i; k <= j; k++) //polynomial hash w/ a = 31
                hash = hash*31 + str[k];

            System.out.println(!hm.containsKey(hash)); //debugging purposes

            // faulty code?

            if (!hm.containsKey(hash));
                hm.put(hash, 0);
            //

            hm.put(hash, hm.get(hash)+1); //update occurrences
        }

false