I am trying to find the unique number of occurrences of each value in the array. I am putting all occurrences of an element in the HashMap. I want to check whether any two adjacent values are the same in HashMap.
I have tried using the Iterator interface to iterate but there seems something missing

class Solution {
    public boolean uniqueOccurrences(int[] arr) {
        boolean uni = true;
        HashMap<Integer, Integer> hm = new HashMap<>();
        
        for (int a : arr) {
            if (hm.containsKey(a)) {
                hm.put(a, hm.get(a) + 1);
            } else {
                hm.put(a, 1);
            }
        }

        // Iterate over the HashMap entries
        Iterator<Map.Entry<Integer, Integer>> it = hm.entrySet().iterator();
        while (it.hasNext()) {
            if (it.next().getValue() == it.getValue()) {
                uni = false;
                break;
            }
        }
        
        return uni;
    }
}