diff --git a/problems/0738.单调递增的数字.md b/problems/0738.单调递增的数字.md
index 400dc90d..4a8a6e08 100644
--- a/problems/0738.单调递增的数字.md
+++ b/problems/0738.单调递增的数字.md
@@ -392,7 +392,33 @@ impl Solution {
     }
 }
 ```
+### C
+
+```c
+int monotoneIncreasingDigits(int n) {
+    char str[11];
+    // 将数字转换为字符串
+    sprintf(str, "%d", n);
+    int len = strlen(str);
+    int flag = strlen(str);
+    for(int i = len - 1; i > 0; i--){
+        if(str[i] < str[i - 1]){
+            str[i - 1]--;
+            flag = i;
+        }
+    }
+    for(int i = flag; i < len; i++){
+        str[i] = '9';
+    }
+    // 字符串转数字
+    return atoi(str);
+}
+```
+
+
+
 ### C#
+
 ```csharp
 public class Solution
 {
@@ -421,4 +447,3 @@ public class Solution
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">
   <img src="../pics/网站星球宣传海报.jpg" width="1000"/>
 </a>
-