isSimilar retainAll change

long-article-recommend-service/src/main/java/com/tzld/longarticle/recommend/server/util/TitleSimilarCheckUtil.java

@@ -58,11 +58,13 @@ public class TitleSimilarCheckUtil {
         if (titleA.isEmpty() || titleB.isEmpty()) {
             return false;
         }
-        int minLen = Math.min(titleA.size(), titleB.size());
-        // since retainAll is an in-place operation, copy it first
-        titleA = new HashSet<>(titleA);
-        titleA.retainAll(titleB);
-        double rate = titleA.size() / (double) minLen;
+        int commonCount = 0;
+        for (Character c : titleA) {
+            if (titleB.contains(c)) {
+                commonCount++;
+            }
+        }
+        double rate = commonCount / (double) Math.min(titleA.size(), titleB.size());
         return rate >= threshold;
     }