1207. Unique Number of Occurrences

class Solution {
    public boolean uniqueOccurrences(int[] arr) 
    {

        int[] freq = new int[2001];
        boolean[] occured = new boolean[2001];

        for(int i:arr)
        {
            freq[i+1000]++;
        }

        for(int i: arr)
        {
            int val = freq[i+1000];
            freq[i+1000]=0;
            
            if(val>0)
            {
                if(occured[val]==true)
                {
                    return false;

                }
                else 
                {
                    occured[val]=true;
                }
            }
        }
        return true;


        /*

        HashMap<Integer, Integer> count = new HashMap<>();
        HashSet<Integer> occurrences = new HashSet<>();

        for(int a : arr)
        {
            count.merge(a, 1, Integer::sum);

        }

        for(int value : count.values())
        {
            if (!occurrences.add(value))
            {
                return false;

            }

        }

        return true;
*/

        
    }
}