diff --git a/source/_posts/homework.md b/source/_posts/homework.md
index e82f85c..19bc27f 100644
--- a/source/_posts/homework.md
+++ b/source/_posts/homework.md
@@ -21,3 +21,8 @@ tags:
 * [题目](/~zhaozuohong/homework3/)
 * [答案](/~zhaozuohong/answer3)
 * [测试数据](/~zhaozuohong/test3)
+
+# 第四次作业
+
+* [题目](/~zhaozuohong/homework4/)
+