diff --git a/.gitignore b/.gitignore
index c795b05..df516c5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
-build
\ No newline at end of file
+build
+compile_commands.json
+.cache
\ No newline at end of file
diff --git a/2138/2138.cpp b/2138/2138.cpp
new file mode 100644
index 0000000..afb5b34
--- /dev/null
+++ b/2138/2138.cpp
@@ -0,0 +1,44 @@
+#include <algorithm>
+#include <string>
+#include <vector>
+
+namespace {
+    class Solution {
+    public:
+        std::vector<std::string> divideString(std::string s, int k, char fill) {
+            std::vector<std::string> res;
+            for (size_t i = 0; i < s.length(); i += k) {
+                auto substr = s.substr(i, std::min<size_t>(k, s.length() - i));
+                if (substr.length() < k) {
+                    auto n = substr.length();
+                    substr.resize(k);
+                    std::fill_n(substr.begin() + n, k - n, fill);
+                }
+                res.emplace_back(substr);
+            }
+            return res;
+        }
+    };
+}
+
+#include <gtest/gtest.h>
+
+TEST(P2138, 1) {
+    std::string input = "abcdefghi";
+    std::vector<std::string> expected = { "abc","def","ghi" };
+    int k = 3;
+    char fill = 'x';
+    Solution s;
+    auto res = s.divideString(input, k, fill);
+    EXPECT_EQ(res, expected);
+}
+
+TEST(P2138, 2) {
+    std::string input = "abcdefghij";
+    std::vector<std::string> expected = { "abc","def","ghi","jxx" };
+    int k = 3;
+    char fill = 'x';
+    Solution s;
+    auto res = s.divideString(input, k, fill);
+    EXPECT_EQ(res, expected);
+}
\ No newline at end of file
diff --git a/justfile b/justfile
index 2f640a5..2013873 100644
--- a/justfile
+++ b/justfile
@@ -1,5 +1,5 @@
 build:
-    cmake -B ./build -S .
+    cmake -B ./build -S . -DCMAKE_EXPORT_COMPILE_COMMANDS=1
     cmake --build ./build --config Debug --target all -j 20 --
 
 test: build