diff --git a/notes/算法.md b/notes/算法.md
index 4d818bad..58f49e4a 100644
--- a/notes/算法.md
+++ b/notes/算法.md
@@ -446,52 +446,6 @@ public class ListQueue<Item> implements MyQueue<Item> {
 }
 ```
 
-```java
-public class Queue<Item> {
-    private Node first;
-    private Node last;
-    int N = 0;
-
-    private class Node {
-        Item item;
-        Node next;
-    }
-
-    public boolean isEmpty() {
-        return N == 0;
-    }
-
-    public int size() {
-        return N;
-    }
-
-    public void add(Item item) {
-        Node newNode = new Node();
-        newNode.item = item;
-        newNode.next = null;
-        if (isEmpty()) {
-            last = newNode;
-            first = newNode;
-        } else {
-            last.next = newNode;
-            last = newNode;
-        }
-        N++;
-    }
-
-    public Item remove() throws Exception {
-        if (isEmpty())
-            throw new Exception("queue is empty");
-        Node node = first;
-        first = first.next;
-        N--;
-        if (isEmpty())
-            last = null;
-        return node.item;
-    }
-}
-```
-
 # 三、排序
 
 待排序的元素需要实现 Java 的 Comparable 接口，该接口有 compareTo() 方法，可以用它来判断两个元素的大小关系。