updated at 2022. 12. 18. 오전 12:46:57

programmers/숫자 짝꿍/solution.java

@@ -6,29 +6,24 @@ import java.util.stream.Stream;
 class Solution {
     public String solution(String X, String Y) {
         String answer = "";
-        LinkedList<Integer> an = new LinkedList<>();
-        HashMap<Integer, Integer> hash = new HashMap<>();
-        HashMap<Integer, Integer> hash2 = new HashMap<>();
-        char[] yy = Y.toCharArray();
-        char[] xx = X.toCharArray();
-        for(char cy : yy){
-            int nn = Character.getNumericValue(cy);
-            hash.put(nn,hash.getOrDefault(nn,0)+1);
+        LinkedList<Integer> linkedList = new LinkedList<>();
+        HashMap<Integer, Integer> hash = new HashMap<>(), hash2 = new HashMap<>();
+        for(char y : Y.toCharArray()){
+            int number = Character.getNumericValue(y);
+            hash.put(number,hash.getOrDefault(number,0)+1);
         }
-        for(char cx : xx){
-            int nn = Character.getNumericValue(cx);
-            hash2.put(nn,hash2.getOrDefault(nn,0)+1);
+        for(char x : X.toCharArray()){
+            int number = Character.getNumericValue(x);
+            hash2.put(number,hash2.getOrDefault(number,0)+1);
         }
         for(Integer key : hash.keySet()){
             if(hash2.getOrDefault(key,0)==0) continue;
-            Integer count = Math.min(hash.get(key),hash2.get(key));
-            for(int oo = 0; oo < count; oo++)
-            an.add(key);
+            int count = Math.min(hash.get(key),hash2.get(key));
+            for(int z = 0; z < count; z++)
+            linkedList.add(key);
         }
-        Object[] ans = an.toArray();
-        answer = Arrays.stream(ans).map(String::valueOf).sorted(Comparator.reverseOrder()).collect(Collectors.joining());
-        answer = (answer.equals(""))? "-1" : answer;
-        answer = (answer.matches("^0+")) ? "0" : answer;
-        return answer;
+        answer = Arrays.stream(linkedList.toArray()).map(String::valueOf)
+            .sorted(Comparator.reverseOrder()).collect(Collectors.joining());
+        return (linkedList.isEmpty())?"-1":((answer.charAt(0)=='0')?"0":answer);
     }
 }