updated at 2022. 12. 15. 오후 4:10:12

programmers/완주하지 못한 선수/solution.java

@@ -1,25 +1,19 @@
 // [문제 링크]: https://school.programmers.co.kr/learn/courses/30/lessons/42576
 
-import java.util.*;
+import java.util.HashMap;
 
 class Solution {
     public String solution(String[] participant, String[] completion) {
         String answer = "";
+        HashMap<String, Integer> hm = new HashMap<>();
+        for (String player : participant) hm.put(player, hm.getOrDefault(player, 0) + 1);
+        for (String player : completion) hm.put(player, hm.get(player) - 1);
 
-        Arrays.sort(participant);
-        Arrays.sort(completion);
-
-        for(int i=0; i<participant.length; i++) {
-            if(!participant[i].equals(completion[i])) {
-                answer = participant[i];
-                break;
+        for (String key : hm.keySet()) {
+            if (hm.get(key) != 0){
+                answer = key;
             }
-            if(i == completion.length) {
-                answer = participant[i];
-                break;
-            } 
         }
-
         return answer;
     }
-}
+}