회사에 있는 사람

package Hash; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.Scanner; // 백준 7785번 회사에 있는 사람 public class Hash01 { static int N; public static void main(String[] args) { HashMap<String, String> hash=new HashMap<>(); Scanner in=new Scanner(System.in); N=in.nextInt(); String[][] map=new String[N][2]; for(int i=0;i<N;i++) { map[i][0]=in.next(); map[i][1]=in.next(); hash.put(map[i][0],map[i][1]); } ArrayList<String> arr=new ArrayList<>(); for(String str: hash.keySet()) if(hash.get(str).equals("enter")) arr.add(str); //대소문자 구분O + 내림 차순 Collections.sort(arr, Collections.reverseOrder()); //대소문자 구분X + 내림차순 //Collections.sort(arr, Collections.reverseOrder(String.CASE_INSENSITIVE_ORDER)); for(String str:arr) System.out.println(str); } }