문제설명
제한사항 및 입출력 예
풀이
import java.util.ArrayList;
import java.util.HashMap;
class Solution {
public String[] solution(String[] record) {
HashMap<String, String> map = new HashMap<>();
HashMap<String, Integer> entrance = new HashMap<>();
ArrayList<String> list = new ArrayList<>();
for (int i = 0; i < record.length; i++) {
String[] arr = record[i].split(" ");
if (record[i].charAt(0) == 'E') {
map.put(arr[1], arr[2]);
entrance.put(arr[1], 0);
list.add(arr[1]);
} else if (record[i].charAt(0) == 'C') {
map.put(arr[1], arr[2]);
} else {
list.add(arr[1]);
}
}
String[] answer = new String[list.size()];
for (int i = 0; i < list.size(); i++) {
if (entrance.get(list.get(i)) == 0) {
entrance.put(list.get(i), 1);
answer[i] = map.get(list.get(i)) + "님이 들어왔습니다.";
} else {
entrance.put(list.get(i), 0);
answer[i] = map.get(list.get(i)) + "님이 나갔습니다.";
}
}
return answer;
}
}