diff --git a/problems/0001.两数之和.md b/problems/0001.两数之和.md
index 5b840acf..f8c9da5f 100644
--- a/problems/0001.两数之和.md
+++ b/problems/0001.两数之和.md
@@ -62,7 +62,7 @@ std::unordered_map 底层实现为哈希表，std::map 和std::multimap 的底
 
 C++代码：
 
-```C++
+```CPP
 class Solution {
 public:
     vector<int> twoSum(vector<int>& nums, int target) {