diff --git a/readme.md b/readme.md
index ea22c1a9b285520e80ec5b15bbffd550d561621b..268a2022a9b7871cb49be7d9dc5bf3383512082f 100644
--- a/readme.md
+++ b/readme.md
@@ -216,6 +216,7 @@ LeetCode 指南
 | 493 [Java](./code/lc493.java)
 | 494 [Java](./code/lc494.java)
 | 538 [Java](./code/lc538.java)
+| 542 [Java](./code/lc542.java)
 | 543 [Java](./code/lc543.java)
 | 559 [Java](./code/lc559.java)
 | 560 [Java](./code/lc543.java)