[LeetCode/Java] 383. Ransom Note

-Code

class Solution {
    public boolean canConstruct(String ransomNote, String magazine) {
        Map<Character, Integer> map = new HashMap<>();

        for (char c : magazine.toCharArray()) {
            map.put(c, map.getOrDefault(c, 0) + 1);
        }

        for (char c2 : ransomNote.toCharArray()) {
            Integer c2_cnt = map.get(c2);
            c2_cnt = (c2_cnt == null ? 0 : c2_cnt) - 1;

            if (c2_cnt < 0) {
                return false;
            }
            map.put(c2, c2_cnt);
        }

        return true;
    }
}