diff --git a/programmers/[3차] 압축/solution.java b/programmers/[3차] 압축/solution.java
new file mode 100644
index 0000000..1e5fc6e
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+++ b/programmers/[3차] 압축/solution.java	
@@ -0,0 +1,28 @@
+// [문제 링크]: https://school.programmers.co.kr/learn/courses/30/lessons/17684
+
+import java.util.*;
+class Solution {
+    public int[] solution(String msg) {
+        ArrayList<Integer> al = new ArrayList<>();
+        int idx = 27;
+        HashMap<String,Integer> hm = new HashMap<>();
+         for(char a = 'A'; a <= 'Z'; a++){
+            String t = String.valueOf(a);
+            hm.put(t,a-64);
+        }
+        for(int a = 0; a < msg.length();){
+            int i = 1, res = 0;
+            while(a+i<= msg.length()){
+                if(hm.containsKey(msg.substring(a,a+i))){
+              res = hm.get(msg.substring(a,a+i++));
+                } else{
+                    hm.put( msg.substring(a,a+i--), idx++ );
+                    break;
+                }
+            }
+            al.add(res);
+            a += i;
+        }
+        return al.stream().mapToInt(x -> x).toArray();
+    }
+}
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