diff --git a/programmers/햄버거 만들기/solution.java b/programmers/햄버거 만들기/solution.java
index c85ce9f..77c24a1 100644
--- a/programmers/햄버거 만들기/solution.java	
+++ b/programmers/햄버거 만들기/solution.java	
@@ -1,34 +1,20 @@
 // [문제 링크]: https://school.programmers.co.kr/learn/courses/30/lessons/133502
 
-import java.util.*;
-
 class Solution {
-    public int solution(int[] ingr) {
+    public int solution(int[] ingredient) {
+        int[] stack = new int[ingredient.length];
+        int sp = 0;
         int answer = 0;
-		ArrayList<Integer> list = new ArrayList<>();
-		ArrayList<Integer> list2 = new ArrayList<>();
-        list2.add(1);
-        list2.add(2);
-        list2.add(3);
-        list2.add(1);
-        for (int i = 0; i < ingr.length; i++){
-            list.add(ingr[i]);
-            if(list.size() >= 4){
-                ArrayList<Integer> list3 = new ArrayList<>();
-                list3.add(list.get(list.size()-4));
-                list3.add(list.get(list.size()-3));
-                list3.add(list.get(list.size()-2));
-                list3.add(list.get(list.size()-1));
-                if(list3.equals(list2)){
-                    answer++;
-                    list.remove(list.size()-1);                    
-                    list.remove(list.size()-1);                    
-                    list.remove(list.size()-1);                
-                    list.remove(list.size()-1);                    
-                }
+        for (int i : ingredient) {
+            stack[sp++] = i;
+            if (sp >= 4 && stack[sp - 1] == 1
+                && stack[sp - 2] == 3
+                && stack[sp - 3] == 2
+                && stack[sp - 4] == 1) {
+                sp -= 4;
+                answer++;
             }
         }
-        
         return answer;
     }
 }
\ No newline at end of file