check my code

[cinder summit]

public class Solution{
    public static char findTheDifference(String s, String t){
        HashMap<Character, Integer> map = new HashMap<>();
        for(Character ch : s.toCharArray()){
            map.put(ch, map.getOrDefault(ch, 0)+1);
        }
        for(Character ch: t.toCharArray()){
            if(map.containsKey(ch) && map.get(ch)>0){
                map.put(ch, map.get(ch)-1);
                if(map.get(ch) == 0){
                    map.remove(ch);
                }
            }else{
                return ch;
            }
        }
        return ' ';
    }
}```
Is there any other method to do this other than Hashmap

[honest saddle]

⌛ This post has been reserved for your question.

Hey @cinder summit! Please use /close or the Close Post button above when your problem is solved. Please remember to follow the help guidelines. This post will be automatically marked as dormant after 720 minutes of inactivity.

TIP: Narrow down your issue to simple and precise questions to maximize the chance that others will reply in here.

[vernal radish]

There are better methods than put(key, get(key)+1):

map.merge(key, 1, Integer::sum);

Also there is collect(Collectors.groupingBy(c -> c, Collectors.counting())) on the character stream (chars()).

If you know the range of the input characters beforehand (e.g. only lowercase ascii) you could also just use an array for counting.

[cinder summit]