LeetCode #242. Valid Anagram

class Solution {
    public boolean isAnagram(String s, String t) {
        if (s.length() != t.length()) {
            return false;
        }

        Map<Character, Integer> mapS = new HashMap<>();
        for (char c : s.toCharArray()) {
            mapS.put(c, mapS.getOrDefault(c, 0) +1);
        }

        Map<Character, Integer> mapT = new HashMap<>();
        for (char c : t.toCharArray()) {
            mapT.put(c, mapT.getOrDefault(c, 0) +1);
        }

        return mapT.equals(mapS);
    }
}