leetcode 第383题

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

        for (char c : magazine.toCharArray()) 
        {
            if (map.containsKey(c)) {
                map.put(c, map.get(c)+1);
            } else {
                map.put(c, 1);
            }
        }

        for (char c : ransomNote.toCharArray())
        {
            if (map.containsKey(c)) 
            {
                map.put(c, map.get(c)-1);
            }

            if (map.containsKey(c) && map.get(c) < 0)
            {
                return false;
            }

            if (!map.containsKey(c)) 
            {
                return false;
            }
        }

        return true;
    }
}