프로그래머스 - 완주하지 못한 선수 (java)

class Solution {
    public String solution(String[] participant, String[] completion) {
        String answer = "";

        java.util.Map<String, Integer> participantMap = new java.util.HashMap<>();

        for (String name : participant) {
            if (participantMap.containsKey(name)) {
                Integer count = participantMap.get(name);
                participantMap.replace(name, ++count);
            } else {
                participantMap.put(name, 1);
            }
        }

        for (String name : completion) {
            if (participantMap.containsKey(name)) {
                Integer count = participantMap.get(name);
                count -= 1;
                if (count <= 0) {
                    participantMap.remove(name);
                    continue;
                }
                participantMap.replace(name, count);
            }
        }

        for (String key : participantMap.keySet()) {
            answer = key;
        }

        return answer;
    }
}