Minimum deletions to make character frequencies unique

// Minimum deletions to make character frequencies unique - medium - 30/08/2023

public int minDeletions(String s) {
        
        int[] count = new int[26];

        for(char c: s.toCharArray()){
            count[c-'a']++;
        }

        Map<Integer, Integer> freqsMap = new HashMap<>();
	    for (int n: count) if (n != 0) freqsMap.put(n, freqsMap.getOrDefault(n,0) + 1);

	    PriorityQueue<Integer> pq = new PriorityQueue<>(Collections.reverseOrder());
	    for (int key: freqsMap.keySet()) pq.add(key);

	    int deletions = 0;
	    while (!pq.isEmpty()) {
	    	int val = pq.poll(), freq = freqsMap.get(val);
	    	deletions += freq - 1;
	    	if (freq > 1 && val > 1) {
	    		if (!freqsMap.containsKey(val-1)) pq.add(val-1);
	    		freqsMap.put(val-1, freqsMap.getOrDefault(val-1,0) + freq-1);
	    	}
	    }

	    return deletions;
    }

// Approach 2 - optimized

ublic int minDeletions(String s) {
        int deletion=0;
        int []freq=new int[26];

        for(char c : s.toCharArray()){
            freq[c-'a']++;
        }

        HashSet<Integer> uniqueelement = new HashSet<>();
        for(int count:freq){
            while(count>0 && uniqueelement.contains(count)){
                deletion++;
                count--;
            }
            uniqueelement.add(count);
        }
        return deletion;
    }