diff --git a/.clang-format b/.clang-format
index fa6e7ac..40ce86b 100644
--- a/.clang-format
+++ b/.clang-format
@@ -7,7 +7,6 @@ AllowShortBlocksOnASingleLine: Always
 AlwaysBreakTemplateDeclarations: 'Yes'
 BasedOnStyle: LLVM
 ColumnLimit: 120
-IfMacros: [ONLY, ONCE, TWICE, EVERY]
 IndentWidth: 4
 InsertNewlineAtEOF: true
 SpaceBeforeParens: ControlStatementsExceptControlMacros
diff --git a/leetcode/0001/solution.hpp b/leetcode/0001/solution.hpp
index dbea879..345bc7a 100644
--- a/leetcode/0001/solution.hpp
+++ b/leetcode/0001/solution.hpp
@@ -1,3 +1,4 @@
+#pragma once
 #include <cstdlib>
 #include <unordered_map>
 #include <vector>
diff --git a/leetcode/0001/test.cpp b/leetcode/0001/test.cpp
index e30cf4a..b224515 100644
--- a/leetcode/0001/test.cpp
+++ b/leetcode/0001/test.cpp
@@ -1,5 +1,5 @@
-#include "test.hpp"
 #include "solution.hpp"
+#include "test_utility.hpp"
 
 using namespace testing;
 namespace {
diff --git a/leetcode/0392/solution.hpp b/leetcode/0392/solution.hpp
index 8341eeb..2d15c2f 100644
--- a/leetcode/0392/solution.hpp
+++ b/leetcode/0392/solution.hpp
@@ -1,3 +1,4 @@
+#pragma once
 #include <string>
 
 // 方法1：双指针
diff --git a/leetcode/0392/test.cpp b/leetcode/0392/test.cpp
index b57c67d..2e4ed6c 100644
--- a/leetcode/0392/test.cpp
+++ b/leetcode/0392/test.cpp
@@ -1,5 +1,5 @@
-#include "test.hpp"
 #include "solution.hpp"
+#include "test_utility.hpp"
 
 using namespace testing;
 namespace {
diff --git a/leetcode/2011/solution.hpp b/leetcode/2011/solution.hpp
index 88906e6..f239b2e 100644
--- a/leetcode/2011/solution.hpp
+++ b/leetcode/2011/solution.hpp
@@ -1,3 +1,4 @@
+#pragma once
 #include <algorithm>
 #include <string>
 #include <vector>
diff --git a/leetcode/2011/test.cpp b/leetcode/2011/test.cpp
index 67b4bc1..5537561 100644
--- a/leetcode/2011/test.cpp
+++ b/leetcode/2011/test.cpp
@@ -1,5 +1,5 @@
-#include "test.hpp"
 #include "solution.hpp"
+#include "test_utility.hpp"
 
 using namespace testing;
 namespace {
diff --git a/leetcode/3346/solution.hpp b/leetcode/3346/solution.hpp
index 931c13f..f7d22db 100644
--- a/leetcode/3346/solution.hpp
+++ b/leetcode/3346/solution.hpp
@@ -1,3 +1,4 @@
+#pragma once
 #include <algorithm>
 #include <ranges>
 #include <vector>
diff --git a/leetcode/3346/test.cpp b/leetcode/3346/test.cpp
index 71117b5..5c1293e 100644
--- a/leetcode/3346/test.cpp
+++ b/leetcode/3346/test.cpp
@@ -1,5 +1,5 @@
-#include "test.hpp"
 #include "solution.hpp"
+#include "test_utility.hpp"
 
 using namespace testing;
 namespace {
diff --git a/leetcode/3347/solution.hpp b/leetcode/3347/solution.hpp
index 5690cfc..49b81be 100644
--- a/leetcode/3347/solution.hpp
+++ b/leetcode/3347/solution.hpp
@@ -1,3 +1,4 @@
+#pragma once
 #include <algorithm>
 #include <ranges>
 #include <vector>
diff --git a/leetcode/3347/test.cpp b/leetcode/3347/test.cpp
index 1eeb6fa..51b7637 100644
--- a/leetcode/3347/test.cpp
+++ b/leetcode/3347/test.cpp
@@ -1,5 +1,5 @@
-#include "test.hpp"
 #include "solution.hpp"
+#include "test_utility.hpp"
 
 using namespace testing;
 namespace {
diff --git a/leetcode/3397-maximum-number-of-distinct-elements-after-operations/solution.hpp b/leetcode/3397-maximum-number-of-distinct-elements-after-operations/solution.hpp
deleted file mode 100644
index 6503298..0000000
--- a/leetcode/3397-maximum-number-of-distinct-elements-after-operations/solution.hpp
+++ /dev/null
@@ -1,18 +0,0 @@
-#include <algorithm>
-#include <vector>
-
-class Solution {
-public:
-    int maxDistinctElements(std::vector<int> &nums, int k) {
-        std::sort(nums.begin(), nums.end());
-        int count = 1;
-        int min_v = nums[0] - k + 1;
-        for (int i{1}; i < nums.size(); ++i) {
-            if (nums[i] + k >= min_v) {
-                min_v = std::max(min_v, nums[i] - k) + 1;
-                count++;
-            }
-        }
-        return count;
-    }
-};
diff --git a/leetcode/3397/solution.hpp b/leetcode/3397/solution.hpp
new file mode 100644
index 0000000..d5859e4
--- /dev/null
+++ b/leetcode/3397/solution.hpp
@@ -0,0 +1,20 @@
+#pragma once
+#include <algorithm>
+#include <ranges>
+#include <vector>
+
+// 方法1：贪心
+struct Solution {
+    static int maxDistinctElements(std::vector<int> nums, int k) {
+        std::ranges::sort(nums);
+        int res{1}, prev{nums[0] - k};
+        for (std::size_t i{1}; i < nums.size(); ++i) {
+            if (nums[i] + k > prev) {
+                // 每个数都取可能的最小值
+                prev = std::max(prev + 1, nums[i] - k);
+                ++res;
+            }
+        }
+        return res;
+    }
+};
diff --git a/leetcode/3397/test.cpp b/leetcode/3397/test.cpp
new file mode 100644
index 0000000..d08a9ad
--- /dev/null
+++ b/leetcode/3397/test.cpp
@@ -0,0 +1,39 @@
+#include "solution.hpp"
+#include "test_utility.hpp"
+
+using namespace testing;
+namespace {
+using SolutionList = TypeList<Solution>;
+struct TestCase {
+    TestCase(const YAML::Node &node) {
+        Decode(node["input"]["nums"], input.nums);
+        Decode(node["input"]["k"], input.k);
+        Decode(node["expected"], expected);
+    }
+    struct {
+        std::vector<int> nums;
+        int k;
+    } input;
+    int expected;
+};
+
+template <typename Solution>
+void RunTest(const std::vector<int> &nums, const int k, const int expected) {
+    // 检查约束条件
+    ASSERT_THAT(nums.size(), AllOf(Ge(1), Le(E<5>))); // 1 <= nums.length <= 10^5
+    ASSERT_THAT(nums, Each(AllOf(Ge(1), Le(E<9>))));  // 1 <= nums[i] <= 10^9
+    ASSERT_THAT(k, AllOf(Ge(1), Le(E<9>)));           // 0 <= k <= 10^9
+
+    // 测试目标函数
+    Solution solution;
+    EXPECT_EQ(solution.maxDistinctElements(nums, k), expected);
+}
+
+template <typename Solution>
+void RunTest(const TestCase &tc) {
+    RunTest<Solution>(tc.input.nums, tc.input.k, tc.expected);
+}
+
+TEST_Y(LeetCode3397, Example1);
+TEST_Y(LeetCode3397, Example2);
+} // namespace
diff --git a/leetcode/3397/test_suite.yaml b/leetcode/3397/test_suite.yaml
new file mode 100644
index 0000000..b4c9c2c
--- /dev/null
+++ b/leetcode/3397/test_suite.yaml
@@ -0,0 +1,11 @@
+example1:
+  input:
+    nums: [1,2,2,3,3,4]
+    k: 2
+  expected: 6
+
+example2:
+  input:
+    nums: [4,4,4,4]
+    k: 1
+  expected: 3
diff --git a/leetcode/3397/title.txt b/leetcode/3397/title.txt
new file mode 100644
index 0000000..48788ee
--- /dev/null
+++ b/leetcode/3397/title.txt
@@ -0,0 +1 @@
+maximum-number-of-distinct-elements-after-operations
diff --git a/leetcode/3461/solution.hpp b/leetcode/3461/solution.hpp
index e52db2a..0e61d39 100644
--- a/leetcode/3461/solution.hpp
+++ b/leetcode/3461/solution.hpp
@@ -1,3 +1,4 @@
+#pragma once
 #include <string>
 
 struct Solution {
diff --git a/leetcode/3461/test.cpp b/leetcode/3461/test.cpp
index 02ed0cd..7214a9d 100644
--- a/leetcode/3461/test.cpp
+++ b/leetcode/3461/test.cpp
@@ -1,5 +1,5 @@
-#include "test.hpp"
 #include "solution.hpp"
+#include "test_utility.hpp"
 
 using namespace testing;
 namespace {
diff --git a/leetcode/CMakeLists.txt b/leetcode/CMakeLists.txt
index 2e8b71f..6d9e7f4 100644
--- a/leetcode/CMakeLists.txt
+++ b/leetcode/CMakeLists.txt
@@ -1,5 +1,5 @@
 # 构建测试对象库
-file(GLOB_RECURSE TEST_SRC "*/test.cpp")
+file(GLOB_RECURSE TEST_SRC "*.cpp")
 add_library(test_leetcode_o OBJECT ${TEST_SRC})
 target_include_directories(test_leetcode_o PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/test)
 target_compile_definitions(test_leetcode_o PRIVATE PROBLEM_PATH=\"${CMAKE_CURRENT_SOURCE_DIR}\")
diff --git a/leetcode/test/test.cpp b/leetcode/test/test_utility.cpp
similarity index 96%
rename from leetcode/test/test.cpp
rename to leetcode/test/test_utility.cpp
index dbb9948..0e38d74 100644
--- a/leetcode/test/test.cpp
+++ b/leetcode/test/test_utility.cpp
@@ -1,4 +1,4 @@
-#include "test.hpp"
+#include "test_utility.hpp"
 
 #include <cctype>
 #include <filesystem>
diff --git a/leetcode/test/test.hpp b/leetcode/test/test_utility.hpp
similarity index 99%
rename from leetcode/test/test.hpp
rename to leetcode/test/test_utility.hpp
index 157d3b5..4534698 100644
--- a/leetcode/test/test.hpp
+++ b/leetcode/test/test_utility.hpp
@@ -1,3 +1,4 @@
+#pragma once
 #include "yaml-cpp/yaml.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"