may solve build issue

Sosuke23 · Sosuke23 · commit 0df0a0398640 · 2025-11-26T08:04:03.000+05:30
diff --git a/src/data_structures/fenwick.md b/src/data_structures/fenwick.md
@@ -165,7 +165,7 @@ Also this implementation supports two constructors.
 You can create a Fenwick tree initialized with zeros, or you can convert an existing array into the Fenwick form.
 
 === "C++"
-    ```cpp
+    ```{.cpp file=fenwick_sum}
     struct FenwickTree {
         vector<int> bit;  // binary indexed tree
         int n;
@@ -253,7 +253,7 @@ Additionally, each time a value is `update`'d, the new value has to be smaller t
 Both significant limitations are because the $min$ operation together with the set of integers doesn't form a group, as there are no inverse elements.
 
 === "C++"
-    ```cpp
+    ```{.cpp file=fenwick_min}
     struct FenwickTreeMin {
         vector<int> bit;
         int n;
@@ -436,7 +436,7 @@ As you can see, the main benefit of this approach is that the binary operations
 The following implementation can be used like the other implementations, however it uses one-based indexing internally.
 
 === "C++"
-    ```cpp
+    ```{.cpp file=fenwick_sum_onebased}
     struct FenwickTreeOneBasedIndexing {
         vector<int> bit;  // binary indexed tree
         int n;
