From 533d488192723aca693cb8800dfd4b6b4cd51e5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9C=B1=E9=AA=8F=E6=9D=B0?= <zhujunjie@sundear.com>
Date: Tue, 28 Sep 2021 15:10:36 +0800
Subject: [PATCH] =?UTF-8?q?finish=20=E7=BB=84=E5=90=88?=
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---
 .../github/hcsp/inheritance/CountingSet.java  | 25 ++++++++++++++-----
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/main/java/com/github/hcsp/inheritance/CountingSet.java b/src/main/java/com/github/hcsp/inheritance/CountingSet.java
index 9311eaf..a524fff 100644
--- a/src/main/java/com/github/hcsp/inheritance/CountingSet.java
+++ b/src/main/java/com/github/hcsp/inheritance/CountingSet.java
@@ -4,20 +4,33 @@
 import java.util.Collection;
 import java.util.HashSet;
 
-public class CountingSet extends HashSet<Object> {
-    /** 统计"有史以来"向该集合中添加过的元素个数 */
+public class CountingSet {
+    /**
+     * 统计"有史以来"向该集合中添加过的元素个数
+     */
+    HashSet<Object> set = new HashSet<>();
     private int count = 0;
 
-    @Override
+    public boolean remove(Object obj) {
+        return set.remove(obj);
+    }
+
     public boolean add(Object obj) {
         count++;
-        return super.add(obj);
+        return set.add(obj);
     }
 
-    @Override
     public boolean addAll(Collection c) {
         count += c.size();
-        return super.addAll(c);
+        return set.addAll(c);
+    }
+
+    public int size() {
+        return set.size();
+    }
+
+    public Boolean removeAll(Collection c) {
+        return set.removeAll(c);
     }
 
     public int getCount() {