diff --git a/codes/c/CMakeLists.txt b/codes/c/CMakeLists.txt
index 8a58eaa92..6128fceba 100644
--- a/codes/c/CMakeLists.txt
+++ b/codes/c/CMakeLists.txt
@@ -5,7 +5,6 @@ set(CMAKE_C_STANDARD 11)
 
 include_directories(./include)
 
-add_subdirectory(include)
 add_subdirectory(chapter_computational_complexity)
 add_subdirectory(chapter_array_and_linkedlist)
 add_subdirectory(chapter_stack_and_queue)
diff --git a/codes/c/chapter_array_and_linkedlist/array.c b/codes/c/chapter_array_and_linkedlist/array.c
index 39bfd1bee..4bf8fff5f 100644
--- a/codes/c/chapter_array_and_linkedlist/array.c
+++ b/codes/c/chapter_array_and_linkedlist/array.c
@@ -4,7 +4,7 @@
  * Author: MolDuM (moldum@163.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 随机返回一个数组元素 */
 int randomAccess(int *nums, int size) {
diff --git a/codes/c/chapter_array_and_linkedlist/linked_list.c b/codes/c/chapter_array_and_linkedlist/linked_list.c
index af2ad758b..8550bfc6f 100644
--- a/codes/c/chapter_array_and_linkedlist/linked_list.c
+++ b/codes/c/chapter_array_and_linkedlist/linked_list.c
@@ -4,7 +4,7 @@
  * Author: Zero (glj0@outlook.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 在链表的节点 n0 之后插入节点 P */
 void insert(ListNode *n0, ListNode *P) {
diff --git a/codes/c/chapter_array_and_linkedlist/my_list.c b/codes/c/chapter_array_and_linkedlist/my_list.c
index fce465178..f8ab8f560 100644
--- a/codes/c/chapter_array_and_linkedlist/my_list.c
+++ b/codes/c/chapter_array_and_linkedlist/my_list.c
@@ -4,7 +4,7 @@
  * Author: Zero (glj0@outlook.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 列表类简易实现 */
 struct myList {
diff --git a/codes/c/chapter_binary_search/binary_search.c b/codes/c/chapter_binary_search/binary_search.c
index 2ec3a230a..250b04e60 100644
--- a/codes/c/chapter_binary_search/binary_search.c
+++ b/codes/c/chapter_binary_search/binary_search.c
@@ -4,7 +4,7 @@
  * Author: Guanngxu (446678850@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 二分查找（双闭区间） */
 int binarySearch(int *nums, int len, int target) {
diff --git a/codes/c/chapter_computational_complexity/space_complexity.c b/codes/c/chapter_computational_complexity/space_complexity.c
index 111ea2465..2c9df0eec 100644
--- a/codes/c/chapter_computational_complexity/space_complexity.c
+++ b/codes/c/chapter_computational_complexity/space_complexity.c
@@ -3,7 +3,7 @@
  * Created Time: 2023-04-15
  * Author: Gonglja (glj0@outlook.com)
  */
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 函数 */
 int func() {
diff --git a/codes/c/chapter_computational_complexity/time_complexity.c b/codes/c/chapter_computational_complexity/time_complexity.c
index ef551df8f..c9a2fd2d1 100644
--- a/codes/c/chapter_computational_complexity/time_complexity.c
+++ b/codes/c/chapter_computational_complexity/time_complexity.c
@@ -4,7 +4,7 @@
  * Author: sjinzh (sjinzh@gmail.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 常数阶 */
 int constant(int n) {
diff --git a/codes/c/chapter_computational_complexity/worst_best_time_complexity.c b/codes/c/chapter_computational_complexity/worst_best_time_complexity.c
index 68af78fec..ef00a7a52 100644
--- a/codes/c/chapter_computational_complexity/worst_best_time_complexity.c
+++ b/codes/c/chapter_computational_complexity/worst_best_time_complexity.c
@@ -4,7 +4,7 @@
  * Author: sjinzh (sjinzh@gmail.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 生成一个数组，元素为 { 1, 2, ..., n }，顺序被打乱 */
 int *randomNumbers(int n) {
diff --git a/codes/c/chapter_hashing/array_hash_map.c b/codes/c/chapter_hashing/array_hash_map.c
index 1159fc04a..9b2a0cf4d 100644
--- a/codes/c/chapter_hashing/array_hash_map.c
+++ b/codes/c/chapter_hashing/array_hash_map.c
@@ -4,7 +4,7 @@
  * Author: Guanngxu (446678850@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 哈希表默认数组大小 */
 # define HASH_MAP_DEFAULT_SIZE 100
diff --git a/codes/c/chapter_heap/my_heap.c b/codes/c/chapter_heap/my_heap.c
index 2b6cedf19..d9f7729ff 100644
--- a/codes/c/chapter_heap/my_heap.c
+++ b/codes/c/chapter_heap/my_heap.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 #define MAX_SIZE 5000
 
diff --git a/codes/c/chapter_searching/hashing_search.c b/codes/c/chapter_searching/hashing_search.c
index 24ad7b79b..826649087 100644
--- a/codes/c/chapter_searching/hashing_search.c
+++ b/codes/c/chapter_searching/hashing_search.c
@@ -4,7 +4,7 @@
  * Author: Gonglja (glj0@outlook.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 哈希表 */
 struct hashTable {
diff --git a/codes/c/chapter_searching/leetcode_two_sum.c b/codes/c/chapter_searching/leetcode_two_sum.c
index 969bee80d..d9088ee58 100644
--- a/codes/c/chapter_searching/leetcode_two_sum.c
+++ b/codes/c/chapter_searching/leetcode_two_sum.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 方法一：暴力枚举 */
 int *twoSumBruteForce(int *nums, int numsSize, int target, int *returnSize) {
diff --git a/codes/c/chapter_searching/linear_search.c b/codes/c/chapter_searching/linear_search.c
index 9261721b9..9c97cd104 100644
--- a/codes/c/chapter_searching/linear_search.c
+++ b/codes/c/chapter_searching/linear_search.c
@@ -4,7 +4,7 @@
  * Author: Guanngxu (446678850@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 线性查找（数组） */
 int linearSearchArray(int *nums, int len, int target) {
diff --git a/codes/c/chapter_sorting/bubble_sort.c b/codes/c/chapter_sorting/bubble_sort.c
index 5a21d767e..59181d3e0 100644
--- a/codes/c/chapter_sorting/bubble_sort.c
+++ b/codes/c/chapter_sorting/bubble_sort.c
@@ -4,7 +4,7 @@
  * Author: Listening (https://github.com/L-Super)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 冒泡排序 */
 void bubbleSort(int nums[], int size) {
diff --git a/codes/c/chapter_sorting/counting_sort.c b/codes/c/chapter_sorting/counting_sort.c
index 1510e641a..dea63303c 100644
--- a/codes/c/chapter_sorting/counting_sort.c
+++ b/codes/c/chapter_sorting/counting_sort.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com), Guanngxu (446678850@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 计数排序 */
 // 简单实现，无法用于排序对象
diff --git a/codes/c/chapter_sorting/insertion_sort.c b/codes/c/chapter_sorting/insertion_sort.c
index 632335ef8..32ca1e9b4 100644
--- a/codes/c/chapter_sorting/insertion_sort.c
+++ b/codes/c/chapter_sorting/insertion_sort.c
@@ -4,7 +4,7 @@
  * Author: Listening (https://github.com/L-Super)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 插入排序 */
 void insertionSort(int nums[], int size) {
diff --git a/codes/c/chapter_sorting/merge_sort.c b/codes/c/chapter_sorting/merge_sort.c
index 6b2916492..0a3b934af 100644
--- a/codes/c/chapter_sorting/merge_sort.c
+++ b/codes/c/chapter_sorting/merge_sort.c
@@ -4,7 +4,7 @@
  * Author: Guanngxu (446678850@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 合并左子数组和右子数组 */
 // 左子数组区间 [left, mid]
diff --git a/codes/c/chapter_sorting/quick_sort.c b/codes/c/chapter_sorting/quick_sort.c
index 66ded35e9..b1648eba3 100644
--- a/codes/c/chapter_sorting/quick_sort.c
+++ b/codes/c/chapter_sorting/quick_sort.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 元素交换 */
 void swap(int nums[], int i, int j) {
diff --git a/codes/c/chapter_sorting/radix_sort.c b/codes/c/chapter_sorting/radix_sort.c
index 65870a6a0..be74e6dbc 100644
--- a/codes/c/chapter_sorting/radix_sort.c
+++ b/codes/c/chapter_sorting/radix_sort.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 获取元素 num 的第 k 位，其中 exp = 10^(k-1) */
 int digit(int num, int exp) {
diff --git a/codes/c/chapter_stack_and_queue/array_deque.c b/codes/c/chapter_stack_and_queue/array_deque.c
index e7c4d8964..c27738999 100644
--- a/codes/c/chapter_stack_and_queue/array_deque.c
+++ b/codes/c/chapter_stack_and_queue/array_deque.c
@@ -4,7 +4,7 @@
  * Author: Gonglja (glj0@outlook.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 基于环形数组实现的双向队列 */
 struct arrayDeque {
diff --git a/codes/c/chapter_stack_and_queue/array_queue.c b/codes/c/chapter_stack_and_queue/array_queue.c
index 6aaedf410..da8fd27ab 100644
--- a/codes/c/chapter_stack_and_queue/array_queue.c
+++ b/codes/c/chapter_stack_and_queue/array_queue.c
@@ -4,7 +4,7 @@
  * Author: Zero (glj0@outlook.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 基于环形数组实现的队列 */
 struct arrayQueue {
diff --git a/codes/c/chapter_stack_and_queue/array_stack.c b/codes/c/chapter_stack_and_queue/array_stack.c
index c96c1ffb7..4eec6e3fe 100644
--- a/codes/c/chapter_stack_and_queue/array_stack.c
+++ b/codes/c/chapter_stack_and_queue/array_stack.c
@@ -4,7 +4,7 @@
  * Author: Zero (glj0@outlook.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 #define MAX_SIZE 5000
 
diff --git a/codes/c/chapter_stack_and_queue/linkedlist_deque.c b/codes/c/chapter_stack_and_queue/linkedlist_deque.c
index 170f524e6..186a1f4b0 100644
--- a/codes/c/chapter_stack_and_queue/linkedlist_deque.c
+++ b/codes/c/chapter_stack_and_queue/linkedlist_deque.c
@@ -4,7 +4,7 @@
  * Author: Gonglja (glj0@outlook.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 双向链表节点 */
 struct doublyListNode {
diff --git a/codes/c/chapter_stack_and_queue/linkedlist_queue.c b/codes/c/chapter_stack_and_queue/linkedlist_queue.c
index b5a208f48..b579b8271 100644
--- a/codes/c/chapter_stack_and_queue/linkedlist_queue.c
+++ b/codes/c/chapter_stack_and_queue/linkedlist_queue.c
@@ -4,7 +4,7 @@
  * Author: Gonglja (glj0@outlook.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 基于链表实现的队列 */
 struct linkedListQueue {
diff --git a/codes/c/chapter_stack_and_queue/linkedlist_stack.c b/codes/c/chapter_stack_and_queue/linkedlist_stack.c
index 92872b552..d47b29112 100644
--- a/codes/c/chapter_stack_and_queue/linkedlist_stack.c
+++ b/codes/c/chapter_stack_and_queue/linkedlist_stack.c
@@ -4,7 +4,7 @@
  * Author: Zero (glj0@outlook.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 基于链表实现的栈 */
 struct linkedListStack {
diff --git a/codes/c/chapter_tree/avl_tree.c b/codes/c/chapter_tree/avl_tree.c
index 4222482dd..7838a9fa4 100644
--- a/codes/c/chapter_tree/avl_tree.c
+++ b/codes/c/chapter_tree/avl_tree.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* AVL Tree */
 struct aVLTree {
diff --git a/codes/c/chapter_tree/binary_search_tree.c b/codes/c/chapter_tree/binary_search_tree.c
index 34f81b23b..7e7da8dd6 100644
--- a/codes/c/chapter_tree/binary_search_tree.c
+++ b/codes/c/chapter_tree/binary_search_tree.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 二叉搜索树 */
 struct binarySearchTree {
diff --git a/codes/c/chapter_tree/binary_tree.c b/codes/c/chapter_tree/binary_tree.c
index 4b6413eb4..1254d4538 100644
--- a/codes/c/chapter_tree/binary_tree.c
+++ b/codes/c/chapter_tree/binary_tree.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* Driver Code */
 int main() {
diff --git a/codes/c/chapter_tree/binary_tree_bfs.c b/codes/c/chapter_tree/binary_tree_bfs.c
index d20bc5430..8e770b491 100644
--- a/codes/c/chapter_tree/binary_tree_bfs.c
+++ b/codes/c/chapter_tree/binary_tree_bfs.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 层序遍历 */
 int *levelOrder(TreeNode *root, int *size) {
diff --git a/codes/c/chapter_tree/binary_tree_dfs.c b/codes/c/chapter_tree/binary_tree_dfs.c
index ab2977536..d82dcf5e8 100644
--- a/codes/c/chapter_tree/binary_tree_dfs.c
+++ b/codes/c/chapter_tree/binary_tree_dfs.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "../include/include.h"
+#include "../utils/common.h"
 
 /* 辅助数组，用于存储遍历序列 */
 int *arr;
diff --git a/codes/c/include/CMakeLists.txt b/codes/c/include/CMakeLists.txt
deleted file mode 100644
index ed9b851ad..000000000
--- a/codes/c/include/CMakeLists.txt
+++ /dev/null
@@ -1,5 +0,0 @@
-add_executable(include
-        include_test.c
-        include.h print_util.h
-        list_node.h tree_node.h
-        uthash.h)
\ No newline at end of file
diff --git a/codes/c/utils/CMakeLists.txt b/codes/c/utils/CMakeLists.txt
new file mode 100644
index 000000000..c1ece2e38
--- /dev/null
+++ b/codes/c/utils/CMakeLists.txt
@@ -0,0 +1,5 @@
+add_executable(utils
+        common_test.c
+        common.h print_util.h
+        list_node.h tree_node.h
+        uthash.h)
\ No newline at end of file
diff --git a/codes/c/include/include.h b/codes/c/utils/common.h
similarity index 96%
rename from codes/c/include/include.h
rename to codes/c/utils/common.h
index f08c75a11..e5565f8e0 100644
--- a/codes/c/include/include.h
+++ b/codes/c/utils/common.h
@@ -1,5 +1,5 @@
 /**
- * File: include.h
+ * File: common.h
  * Created Time: 2022-12-20
  * Author: MolDuM (moldum@163.com)、Reanon (793584285@qq.com)
  */
diff --git a/codes/c/include/include_test.c b/codes/c/utils/common_test.c
similarity index 97%
rename from codes/c/include/include_test.c
rename to codes/c/utils/common_test.c
index 282de9276..5a4942df2 100644
--- a/codes/c/include/include_test.c
+++ b/codes/c/utils/common_test.c
@@ -4,7 +4,7 @@
  * Author: Reanon (793584285@qq.com)
  */
 
-#include "include.h"
+#include "common.h"
 
 void testListNode() {
     int nums[] = {2, 3, 5, 6, 7};
diff --git a/codes/c/include/list_node.h b/codes/c/utils/list_node.h
similarity index 100%
rename from codes/c/include/list_node.h
rename to codes/c/utils/list_node.h
diff --git a/codes/c/include/print_util.h b/codes/c/utils/print_util.h
similarity index 100%
rename from codes/c/include/print_util.h
rename to codes/c/utils/print_util.h
diff --git a/codes/c/include/tree_node.h b/codes/c/utils/tree_node.h
similarity index 100%
rename from codes/c/include/tree_node.h
rename to codes/c/utils/tree_node.h
diff --git a/codes/c/include/uthash.h b/codes/c/utils/uthash.h
similarity index 100%
rename from codes/c/include/uthash.h
rename to codes/c/utils/uthash.h
diff --git a/codes/cpp/chapter_array_and_linkedlist/array.cpp b/codes/cpp/chapter_array_and_linkedlist/array.cpp
index b839ba719..0d909f664 100644
--- a/codes/cpp/chapter_array_and_linkedlist/array.cpp
+++ b/codes/cpp/chapter_array_and_linkedlist/array.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 随机返回一个数组元素 */
 int randomAccess(int *nums, int size) {
diff --git a/codes/cpp/chapter_array_and_linkedlist/linked_list.cpp b/codes/cpp/chapter_array_and_linkedlist/linked_list.cpp
index 0116a682b..ecf3615cd 100644
--- a/codes/cpp/chapter_array_and_linkedlist/linked_list.cpp
+++ b/codes/cpp/chapter_array_and_linkedlist/linked_list.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 在链表的节点 n0 之后插入节点 P */
 void insert(ListNode *n0, ListNode *P) {
diff --git a/codes/cpp/chapter_array_and_linkedlist/list.cpp b/codes/cpp/chapter_array_and_linkedlist/list.cpp
index 5c70746cf..d7ec60a62 100644
--- a/codes/cpp/chapter_array_and_linkedlist/list.cpp
+++ b/codes/cpp/chapter_array_and_linkedlist/list.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* Driver Code */
 int main() {
diff --git a/codes/cpp/chapter_array_and_linkedlist/my_list.cpp b/codes/cpp/chapter_array_and_linkedlist/my_list.cpp
index 0a659ecad..373393572 100644
--- a/codes/cpp/chapter_array_and_linkedlist/my_list.cpp
+++ b/codes/cpp/chapter_array_and_linkedlist/my_list.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 列表类简易实现 */
 class MyList {
diff --git a/codes/cpp/chapter_backtracking/permutations_i.cpp b/codes/cpp/chapter_backtracking/permutations_i.cpp
index 1f268fc60..41704cee4 100644
--- a/codes/cpp/chapter_backtracking/permutations_i.cpp
+++ b/codes/cpp/chapter_backtracking/permutations_i.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 回溯算法：全排列 I */
 void backtrack(vector<int> &state, const vector<int> &choices, vector<bool> &selected, vector<vector<int>> &res) {
diff --git a/codes/cpp/chapter_backtracking/permutations_ii.cpp b/codes/cpp/chapter_backtracking/permutations_ii.cpp
index b06b34fa3..a164f1288 100644
--- a/codes/cpp/chapter_backtracking/permutations_ii.cpp
+++ b/codes/cpp/chapter_backtracking/permutations_ii.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 回溯算法：全排列 II */
 void backtrack(vector<int> &state, const vector<int> &choices, vector<bool> &selected, vector<vector<int>> &res) {
diff --git a/codes/cpp/chapter_backtracking/preorder_traversal_i_compact.cpp b/codes/cpp/chapter_backtracking/preorder_traversal_i_compact.cpp
index 5e8bcaf8c..f18a5b9ce 100644
--- a/codes/cpp/chapter_backtracking/preorder_traversal_i_compact.cpp
+++ b/codes/cpp/chapter_backtracking/preorder_traversal_i_compact.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 vector<TreeNode *> res;
 
diff --git a/codes/cpp/chapter_backtracking/preorder_traversal_ii_compact.cpp b/codes/cpp/chapter_backtracking/preorder_traversal_ii_compact.cpp
index c3f78f19a..e1511256a 100644
--- a/codes/cpp/chapter_backtracking/preorder_traversal_ii_compact.cpp
+++ b/codes/cpp/chapter_backtracking/preorder_traversal_ii_compact.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 vector<TreeNode *> path;
 vector<vector<TreeNode *>> res;
diff --git a/codes/cpp/chapter_backtracking/preorder_traversal_iii_compact.cpp b/codes/cpp/chapter_backtracking/preorder_traversal_iii_compact.cpp
index 8e5d17332..26fe1f14e 100644
--- a/codes/cpp/chapter_backtracking/preorder_traversal_iii_compact.cpp
+++ b/codes/cpp/chapter_backtracking/preorder_traversal_iii_compact.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 vector<TreeNode *> path;
 vector<vector<TreeNode *>> res;
diff --git a/codes/cpp/chapter_backtracking/preorder_traversal_iii_template.cpp b/codes/cpp/chapter_backtracking/preorder_traversal_iii_template.cpp
index 6372b4a46..9c86422b2 100644
--- a/codes/cpp/chapter_backtracking/preorder_traversal_iii_template.cpp
+++ b/codes/cpp/chapter_backtracking/preorder_traversal_iii_template.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 判断当前状态是否为解 */
 bool isSolution(vector<TreeNode *> &state) {
diff --git a/codes/cpp/chapter_binary_search/binary_search.cpp b/codes/cpp/chapter_binary_search/binary_search.cpp
index 3e1d60d32..8d7c41597 100644
--- a/codes/cpp/chapter_binary_search/binary_search.cpp
+++ b/codes/cpp/chapter_binary_search/binary_search.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 二分查找（双闭区间） */
 int binarySearch(vector<int> &nums, int target) {
diff --git a/codes/cpp/chapter_computational_complexity/space_complexity.cpp b/codes/cpp/chapter_computational_complexity/space_complexity.cpp
index e8f499501..d0e284e0b 100644
--- a/codes/cpp/chapter_computational_complexity/space_complexity.cpp
+++ b/codes/cpp/chapter_computational_complexity/space_complexity.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 函数 */
 int func() {
diff --git a/codes/cpp/chapter_computational_complexity/time_complexity.cpp b/codes/cpp/chapter_computational_complexity/time_complexity.cpp
index 426fa0144..253605cea 100644
--- a/codes/cpp/chapter_computational_complexity/time_complexity.cpp
+++ b/codes/cpp/chapter_computational_complexity/time_complexity.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 常数阶 */
 int constant(int n) {
diff --git a/codes/cpp/chapter_computational_complexity/worst_best_time_complexity.cpp b/codes/cpp/chapter_computational_complexity/worst_best_time_complexity.cpp
index 3090fd769..0a6e562f1 100644
--- a/codes/cpp/chapter_computational_complexity/worst_best_time_complexity.cpp
+++ b/codes/cpp/chapter_computational_complexity/worst_best_time_complexity.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 生成一个数组，元素为 { 1, 2, ..., n }，顺序被打乱 */
 vector<int> randomNumbers(int n) {
diff --git a/codes/cpp/chapter_graph/graph_adjacency_list.cpp b/codes/cpp/chapter_graph/graph_adjacency_list.cpp
index 5b0c49a3f..0fad9ac7d 100644
--- a/codes/cpp/chapter_graph/graph_adjacency_list.cpp
+++ b/codes/cpp/chapter_graph/graph_adjacency_list.cpp
@@ -4,7 +4,7 @@
  * Author: what-is-me (whatisme@outlook.jp), Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 基于邻接表实现的无向图类 */
 class GraphAdjList {
diff --git a/codes/cpp/chapter_graph/graph_adjacency_matrix.cpp b/codes/cpp/chapter_graph/graph_adjacency_matrix.cpp
index 781d9adc6..1b36bd507 100644
--- a/codes/cpp/chapter_graph/graph_adjacency_matrix.cpp
+++ b/codes/cpp/chapter_graph/graph_adjacency_matrix.cpp
@@ -4,7 +4,7 @@
  * Author: what-is-me (whatisme@outlook.jp)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 基于邻接矩阵实现的无向图类 */
 class GraphAdjMat {
diff --git a/codes/cpp/chapter_graph/graph_bfs.cpp b/codes/cpp/chapter_graph/graph_bfs.cpp
index 62b849c28..9106df884 100644
--- a/codes/cpp/chapter_graph/graph_bfs.cpp
+++ b/codes/cpp/chapter_graph/graph_bfs.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 #include "./graph_adjacency_list.cpp"
 
 /* 广度优先遍历 BFS */
diff --git a/codes/cpp/chapter_graph/graph_dfs.cpp b/codes/cpp/chapter_graph/graph_dfs.cpp
index 71ab4f21d..d32811240 100644
--- a/codes/cpp/chapter_graph/graph_dfs.cpp
+++ b/codes/cpp/chapter_graph/graph_dfs.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 #include "./graph_adjacency_list.cpp"
 
 /* 深度优先遍历 DFS 辅助函数 */
diff --git a/codes/cpp/chapter_hashing/array_hash_map.cpp b/codes/cpp/chapter_hashing/array_hash_map.cpp
index 5f78191ed..b52db1733 100644
--- a/codes/cpp/chapter_hashing/array_hash_map.cpp
+++ b/codes/cpp/chapter_hashing/array_hash_map.cpp
@@ -4,7 +4,7 @@
  * Author: msk397 (machangxinq@gmail.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 键值对 int->String */
 struct Entry {
diff --git a/codes/cpp/chapter_hashing/hash_map.cpp b/codes/cpp/chapter_hashing/hash_map.cpp
index 4a4e42707..1f295ec7b 100644
--- a/codes/cpp/chapter_hashing/hash_map.cpp
+++ b/codes/cpp/chapter_hashing/hash_map.cpp
@@ -4,7 +4,7 @@
  * Author: msk397 (machangxinq@gmail.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* Driver Code */
 int main() {
diff --git a/codes/cpp/chapter_heap/heap.cpp b/codes/cpp/chapter_heap/heap.cpp
index 558269d50..d7fa44f52 100644
--- a/codes/cpp/chapter_heap/heap.cpp
+++ b/codes/cpp/chapter_heap/heap.cpp
@@ -4,7 +4,7 @@
  * Author: LoneRanger(836253168@qq.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 void testPush(priority_queue<int> &heap, int val) {
     heap.push(val); // 元素入堆
diff --git a/codes/cpp/chapter_heap/my_heap.cpp b/codes/cpp/chapter_heap/my_heap.cpp
index 272c5d243..526d0050c 100644
--- a/codes/cpp/chapter_heap/my_heap.cpp
+++ b/codes/cpp/chapter_heap/my_heap.cpp
@@ -4,7 +4,7 @@
  * Author: LoneRanger (836253168@qq.com), what-is-me (whatisme@outlook.jp)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 大顶堆 */
 class MaxHeap {
diff --git a/codes/cpp/chapter_searching/hashing_search.cpp b/codes/cpp/chapter_searching/hashing_search.cpp
index 7373f51ce..606c0a538 100644
--- a/codes/cpp/chapter_searching/hashing_search.cpp
+++ b/codes/cpp/chapter_searching/hashing_search.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 哈希查找（数组） */
 int hashingSearchArray(unordered_map<int, int> map, int target) {
diff --git a/codes/cpp/chapter_searching/leetcode_two_sum.cpp b/codes/cpp/chapter_searching/leetcode_two_sum.cpp
index 38b76f778..ecbce4b8c 100644
--- a/codes/cpp/chapter_searching/leetcode_two_sum.cpp
+++ b/codes/cpp/chapter_searching/leetcode_two_sum.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 方法一：暴力枚举 */
 vector<int> twoSumBruteForce(vector<int> &nums, int target) {
diff --git a/codes/cpp/chapter_searching/linear_search.cpp b/codes/cpp/chapter_searching/linear_search.cpp
index d0680a0bb..72f232c5e 100644
--- a/codes/cpp/chapter_searching/linear_search.cpp
+++ b/codes/cpp/chapter_searching/linear_search.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 线性查找（数组） */
 int linearSearchArray(vector<int> &nums, int target) {
diff --git a/codes/cpp/chapter_sorting/bubble_sort.cpp b/codes/cpp/chapter_sorting/bubble_sort.cpp
index ca8399302..9e268085c 100644
--- a/codes/cpp/chapter_sorting/bubble_sort.cpp
+++ b/codes/cpp/chapter_sorting/bubble_sort.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 冒泡排序 */
 void bubbleSort(vector<int> &nums) {
diff --git a/codes/cpp/chapter_sorting/bucket_sort.cpp b/codes/cpp/chapter_sorting/bucket_sort.cpp
index 4eb1212d9..8e5cb472b 100644
--- a/codes/cpp/chapter_sorting/bucket_sort.cpp
+++ b/codes/cpp/chapter_sorting/bucket_sort.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 桶排序 */
 void bucketSort(vector<float> &nums) {
diff --git a/codes/cpp/chapter_sorting/counting_sort.cpp b/codes/cpp/chapter_sorting/counting_sort.cpp
index e56f503e8..d01ded6b9 100644
--- a/codes/cpp/chapter_sorting/counting_sort.cpp
+++ b/codes/cpp/chapter_sorting/counting_sort.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 计数排序 */
 // 简单实现，无法用于排序对象
diff --git a/codes/cpp/chapter_sorting/insertion_sort.cpp b/codes/cpp/chapter_sorting/insertion_sort.cpp
index 5444716e6..1d37acb80 100644
--- a/codes/cpp/chapter_sorting/insertion_sort.cpp
+++ b/codes/cpp/chapter_sorting/insertion_sort.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 插入排序 */
 void insertionSort(vector<int> &nums) {
diff --git a/codes/cpp/chapter_sorting/merge_sort.cpp b/codes/cpp/chapter_sorting/merge_sort.cpp
index 3e75507c0..fefb625d1 100644
--- a/codes/cpp/chapter_sorting/merge_sort.cpp
+++ b/codes/cpp/chapter_sorting/merge_sort.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 合并左子数组和右子数组 */
 // 左子数组区间 [left, mid]
diff --git a/codes/cpp/chapter_sorting/quick_sort.cpp b/codes/cpp/chapter_sorting/quick_sort.cpp
index 3c604f49d..327600f0a 100644
--- a/codes/cpp/chapter_sorting/quick_sort.cpp
+++ b/codes/cpp/chapter_sorting/quick_sort.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 快速排序类 */
 class QuickSort {
diff --git a/codes/cpp/chapter_sorting/radix_sort.cpp b/codes/cpp/chapter_sorting/radix_sort.cpp
index b687bc9db..0b52cc4e7 100644
--- a/codes/cpp/chapter_sorting/radix_sort.cpp
+++ b/codes/cpp/chapter_sorting/radix_sort.cpp
@@ -5,7 +5,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 获取元素 num 的第 k 位，其中 exp = 10^(k-1) */
 int digit(int num, int exp) {
diff --git a/codes/cpp/chapter_stack_and_queue/array_deque.cpp b/codes/cpp/chapter_stack_and_queue/array_deque.cpp
index dd7924a2c..248e13a37 100644
--- a/codes/cpp/chapter_stack_and_queue/array_deque.cpp
+++ b/codes/cpp/chapter_stack_and_queue/array_deque.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 基于环形数组实现的双向队列 */
 class ArrayDeque {
diff --git a/codes/cpp/chapter_stack_and_queue/array_queue.cpp b/codes/cpp/chapter_stack_and_queue/array_queue.cpp
index 80be294ae..ea83bf770 100644
--- a/codes/cpp/chapter_stack_and_queue/array_queue.cpp
+++ b/codes/cpp/chapter_stack_and_queue/array_queue.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 基于环形数组实现的队列 */
 class ArrayQueue {
diff --git a/codes/cpp/chapter_stack_and_queue/array_stack.cpp b/codes/cpp/chapter_stack_and_queue/array_stack.cpp
index ff926a050..02df352c8 100644
--- a/codes/cpp/chapter_stack_and_queue/array_stack.cpp
+++ b/codes/cpp/chapter_stack_and_queue/array_stack.cpp
@@ -4,7 +4,7 @@
  * Author: qualifier1024 (2539244001@qq.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 基于数组实现的栈 */
 class ArrayStack {
diff --git a/codes/cpp/chapter_stack_and_queue/deque.cpp b/codes/cpp/chapter_stack_and_queue/deque.cpp
index 014739039..080c60281 100644
--- a/codes/cpp/chapter_stack_and_queue/deque.cpp
+++ b/codes/cpp/chapter_stack_and_queue/deque.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* Driver Code */
 int main() {
diff --git a/codes/cpp/chapter_stack_and_queue/linkedlist_deque.cpp b/codes/cpp/chapter_stack_and_queue/linkedlist_deque.cpp
index 7f4a40b28..d1217a130 100644
--- a/codes/cpp/chapter_stack_and_queue/linkedlist_deque.cpp
+++ b/codes/cpp/chapter_stack_and_queue/linkedlist_deque.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 双向链表节点 */
 struct DoublyListNode {
diff --git a/codes/cpp/chapter_stack_and_queue/linkedlist_queue.cpp b/codes/cpp/chapter_stack_and_queue/linkedlist_queue.cpp
index 80a307c47..400072d3e 100644
--- a/codes/cpp/chapter_stack_and_queue/linkedlist_queue.cpp
+++ b/codes/cpp/chapter_stack_and_queue/linkedlist_queue.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 基于链表实现的队列 */
 class LinkedListQueue {
diff --git a/codes/cpp/chapter_stack_and_queue/linkedlist_stack.cpp b/codes/cpp/chapter_stack_and_queue/linkedlist_stack.cpp
index 543ad6d32..1ec5bee47 100644
--- a/codes/cpp/chapter_stack_and_queue/linkedlist_stack.cpp
+++ b/codes/cpp/chapter_stack_and_queue/linkedlist_stack.cpp
@@ -4,7 +4,7 @@
  * Author: qualifier1024 (2539244001@qq.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 基于链表实现的栈 */
 class LinkedListStack {
diff --git a/codes/cpp/chapter_stack_and_queue/queue.cpp b/codes/cpp/chapter_stack_and_queue/queue.cpp
index 140fad067..b94ba40dd 100644
--- a/codes/cpp/chapter_stack_and_queue/queue.cpp
+++ b/codes/cpp/chapter_stack_and_queue/queue.cpp
@@ -4,7 +4,7 @@
  * Author: qualifier1024 (2539244001@qq.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* Driver Code */
 int main() {
diff --git a/codes/cpp/chapter_stack_and_queue/stack.cpp b/codes/cpp/chapter_stack_and_queue/stack.cpp
index c3d820139..18743bfbb 100644
--- a/codes/cpp/chapter_stack_and_queue/stack.cpp
+++ b/codes/cpp/chapter_stack_and_queue/stack.cpp
@@ -4,7 +4,7 @@
  * Author: qualifier1024 (2539244001@qq.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* Driver Code */
 int main() {
diff --git a/codes/cpp/chapter_tree/avl_tree.cpp b/codes/cpp/chapter_tree/avl_tree.cpp
index 82e01d448..5aaca253f 100644
--- a/codes/cpp/chapter_tree/avl_tree.cpp
+++ b/codes/cpp/chapter_tree/avl_tree.cpp
@@ -4,7 +4,7 @@
  * Author: what-is-me (whatisme@outlook.jp)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* AVL 树 */
 class AVLTree {
diff --git a/codes/cpp/chapter_tree/binary_search_tree.cpp b/codes/cpp/chapter_tree/binary_search_tree.cpp
index 022afeca3..8b8e83bfa 100644
--- a/codes/cpp/chapter_tree/binary_search_tree.cpp
+++ b/codes/cpp/chapter_tree/binary_search_tree.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 二叉搜索树 */
 class BinarySearchTree {
diff --git a/codes/cpp/chapter_tree/binary_tree.cpp b/codes/cpp/chapter_tree/binary_tree.cpp
index 3d7075de4..55d1ef777 100644
--- a/codes/cpp/chapter_tree/binary_tree.cpp
+++ b/codes/cpp/chapter_tree/binary_tree.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* Driver Code */
 int main() {
diff --git a/codes/cpp/chapter_tree/binary_tree_bfs.cpp b/codes/cpp/chapter_tree/binary_tree_bfs.cpp
index abc7846d8..dad366439 100644
--- a/codes/cpp/chapter_tree/binary_tree_bfs.cpp
+++ b/codes/cpp/chapter_tree/binary_tree_bfs.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 /* 层序遍历 */
 vector<int> levelOrder(TreeNode *root) {
diff --git a/codes/cpp/chapter_tree/binary_tree_dfs.cpp b/codes/cpp/chapter_tree/binary_tree_dfs.cpp
index 2ccae4dbd..a756d33e7 100644
--- a/codes/cpp/chapter_tree/binary_tree_dfs.cpp
+++ b/codes/cpp/chapter_tree/binary_tree_dfs.cpp
@@ -4,7 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../include/include.hpp"
+#include "../utils/common.hpp"
 
 // 初始化列表，用于存储遍历序列
 vector<int> vec;
diff --git a/codes/cpp/include/CMakeLists.txt b/codes/cpp/include/CMakeLists.txt
deleted file mode 100644
index c9bc76ab8..000000000
--- a/codes/cpp/include/CMakeLists.txt
+++ /dev/null
@@ -1,4 +0,0 @@
-add_executable(include
-        include.hpp PrintUtil.hpp
-        ListNode.hpp TreeNode.hpp
-        Vertex.hpp)
\ No newline at end of file
diff --git a/codes/cpp/utils/CMakeLists.txt b/codes/cpp/utils/CMakeLists.txt
new file mode 100644
index 000000000..775a55869
--- /dev/null
+++ b/codes/cpp/utils/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_executable(utils
+        common.hpp print_utils.hpp
+        list_node.hpp tree_node.hpp
+        vertex.hpp)
\ No newline at end of file
diff --git a/codes/cpp/include/include.hpp b/codes/cpp/utils/common.hpp
similarity index 74%
rename from codes/cpp/include/include.hpp
rename to codes/cpp/utils/common.hpp
index d0b925dcd..1f557d437 100644
--- a/codes/cpp/include/include.hpp
+++ b/codes/cpp/utils/common.hpp
@@ -1,5 +1,5 @@
 /**
- * File: PrintUtil.hpp
+ * File: common.hpp
  * Created Time: 2021-12-19
  * Author: Krahets (krahets@163.com)
  */
@@ -20,9 +20,9 @@
 #include <unordered_set>
 #include <vector>
 
-#include "ListNode.hpp"
-#include "PrintUtil.hpp"
-#include "TreeNode.hpp"
-#include "Vertex.hpp"
+#include "list_node.hpp"
+#include "print_utils.hpp"
+#include "tree_node.hpp"
+#include "vertex.hpp"
 
 using namespace std;
diff --git a/codes/cpp/include/ListNode.hpp b/codes/cpp/utils/list_node.hpp
similarity index 97%
rename from codes/cpp/include/ListNode.hpp
rename to codes/cpp/utils/list_node.hpp
index 583ad01a5..0e2d94977 100644
--- a/codes/cpp/include/ListNode.hpp
+++ b/codes/cpp/utils/list_node.hpp
@@ -1,5 +1,5 @@
 /**
- * File: PrintUtil.hpp
+ * File: list_node.hpp
  * Created Time: 2021-12-19
  * Author: Krahets (krahets@163.com)
  */
diff --git a/codes/cpp/include/PrintUtil.hpp b/codes/cpp/utils/print_utils.hpp
similarity index 98%
rename from codes/cpp/include/PrintUtil.hpp
rename to codes/cpp/utils/print_utils.hpp
index 840043e64..2edba56ba 100644
--- a/codes/cpp/include/PrintUtil.hpp
+++ b/codes/cpp/utils/print_utils.hpp
@@ -1,13 +1,13 @@
 /**
- * File: PrintUtil.hpp
+ * File: print_utils.hpp
  * Created Time: 2021-12-19
  * Author: Krahets (krahets@163.com), msk397 (machangxinq@gmail.com), LoneRanger(836253168@qq.com)
  */
 
 #pragma once
 
-#include "ListNode.hpp"
-#include "TreeNode.hpp"
+#include "list_node.hpp"
+#include "tree_node.hpp"
 #include <climits>
 #include <iostream>
 #include <sstream>
diff --git a/codes/cpp/include/TreeNode.hpp b/codes/cpp/utils/tree_node.hpp
similarity index 98%
rename from codes/cpp/include/TreeNode.hpp
rename to codes/cpp/utils/tree_node.hpp
index 3d4460159..827ab9fdf 100644
--- a/codes/cpp/include/TreeNode.hpp
+++ b/codes/cpp/utils/tree_node.hpp
@@ -1,5 +1,5 @@
 /**
- * File: PrintUtil.hpp
+ * File: tree_node.hpp
  * Created Time: 2021-12-19
  * Author: Krahets (krahets@163.com)
  */
diff --git a/codes/cpp/include/Vertex.hpp b/codes/cpp/utils/vertex.hpp
similarity index 96%
rename from codes/cpp/include/Vertex.hpp
rename to codes/cpp/utils/vertex.hpp
index b043d015e..447ffc266 100644
--- a/codes/cpp/include/Vertex.hpp
+++ b/codes/cpp/utils/vertex.hpp
@@ -1,5 +1,5 @@
 /**
- * File: PrintUtil.hpp
+ * File: vertex.hpp
  * Created Time: 2023-03-02
  * Author: Krahets (krahets@163.com)
  */
diff --git a/codes/csharp/include/Vertex.cs b/codes/csharp/include/Vertex.cs
index 19b89e8d0..45085817c 100644
--- a/codes/csharp/include/Vertex.cs
+++ b/codes/csharp/include/Vertex.cs
@@ -1,5 +1,5 @@
 /**
- * File: graph_adjacency_list.cs
+ * File: Vertex.cs
  * Created Time: 2023-02-06
  * Author: zjkung1123 (zjkung1123@gmail.com), krahets (krahets@163.com)
  */
diff --git a/codes/dart/utils/list_node.dart b/codes/dart/utils/list_node.dart
index fefd542c4..163f9179b 100644
--- a/codes/dart/utils/list_node.dart
+++ b/codes/dart/utils/list_node.dart
@@ -1,5 +1,5 @@
 /**
- * File: ListNode
+ * File: list_node.dart
  * Created Time: 2023-01-23
  * Author: Jefferson (JeffersonHuang77@gmail.com)
  */
diff --git a/codes/dart/utils/print_util.dart b/codes/dart/utils/print_util.dart
index 5d56b096d..82ac38b06 100644
--- a/codes/dart/utils/print_util.dart
+++ b/codes/dart/utils/print_util.dart
@@ -1,5 +1,5 @@
 /**
- * File: PrintUtil
+ * File: print_util.dart
  * Created Time: 2023-01-23
  * Author: Jefferson (JeffersonHuang77@gmail.com)
  */
diff --git a/codes/java/chapter_array_and_linkedlist/linked_list.java b/codes/java/chapter_array_and_linkedlist/linked_list.java
index 8ec57e28e..d88411f07 100644
--- a/codes/java/chapter_array_and_linkedlist/linked_list.java
+++ b/codes/java/chapter_array_and_linkedlist/linked_list.java
@@ -6,7 +6,7 @@
 
 package chapter_array_and_linkedlist;
 
-import include.*;
+import utils.*;
 
 public class linked_list {
     /* 在链表的节点 n0 之后插入节点 P */
diff --git a/codes/java/chapter_backtracking/preorder_traversal_i_compact.java b/codes/java/chapter_backtracking/preorder_traversal_i_compact.java
index 38b6ac7e9..d36c0b76c 100644
--- a/codes/java/chapter_backtracking/preorder_traversal_i_compact.java
+++ b/codes/java/chapter_backtracking/preorder_traversal_i_compact.java
@@ -6,7 +6,7 @@
 
 package chapter_backtracking;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 public class preorder_traversal_i_compact {
diff --git a/codes/java/chapter_backtracking/preorder_traversal_ii_compact.java b/codes/java/chapter_backtracking/preorder_traversal_ii_compact.java
index 3622bf696..a412aefce 100644
--- a/codes/java/chapter_backtracking/preorder_traversal_ii_compact.java
+++ b/codes/java/chapter_backtracking/preorder_traversal_ii_compact.java
@@ -6,7 +6,7 @@
 
 package chapter_backtracking;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 public class preorder_traversal_ii_compact {
diff --git a/codes/java/chapter_backtracking/preorder_traversal_iii_compact.java b/codes/java/chapter_backtracking/preorder_traversal_iii_compact.java
index 325551520..4ffbb6217 100644
--- a/codes/java/chapter_backtracking/preorder_traversal_iii_compact.java
+++ b/codes/java/chapter_backtracking/preorder_traversal_iii_compact.java
@@ -6,7 +6,7 @@
 
 package chapter_backtracking;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 public class preorder_traversal_iii_compact {
diff --git a/codes/java/chapter_backtracking/preorder_traversal_iii_template.java b/codes/java/chapter_backtracking/preorder_traversal_iii_template.java
index 998050f49..27685a1ec 100644
--- a/codes/java/chapter_backtracking/preorder_traversal_iii_template.java
+++ b/codes/java/chapter_backtracking/preorder_traversal_iii_template.java
@@ -6,7 +6,7 @@
 
 package chapter_backtracking;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 public class preorder_traversal_iii_template {
diff --git a/codes/java/chapter_computational_complexity/space_complexity.java b/codes/java/chapter_computational_complexity/space_complexity.java
index 0ccf7711f..e7c0872f1 100644
--- a/codes/java/chapter_computational_complexity/space_complexity.java
+++ b/codes/java/chapter_computational_complexity/space_complexity.java
@@ -6,7 +6,7 @@
 
 package chapter_computational_complexity;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 public class space_complexity {
diff --git a/codes/java/chapter_graph/graph_adjacency_list.java b/codes/java/chapter_graph/graph_adjacency_list.java
index a9afd70ba..28e1d8f94 100644
--- a/codes/java/chapter_graph/graph_adjacency_list.java
+++ b/codes/java/chapter_graph/graph_adjacency_list.java
@@ -7,7 +7,7 @@
 package chapter_graph;
 
 import java.util.*;
-import include.*;
+import utils.*;
 
 /* 基于邻接表实现的无向图类 */
 class GraphAdjList {
diff --git a/codes/java/chapter_graph/graph_adjacency_matrix.java b/codes/java/chapter_graph/graph_adjacency_matrix.java
index 071574cac..1a9b03f90 100644
--- a/codes/java/chapter_graph/graph_adjacency_matrix.java
+++ b/codes/java/chapter_graph/graph_adjacency_matrix.java
@@ -6,7 +6,7 @@
 
 package chapter_graph;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 /* 基于邻接矩阵实现的无向图类 */
diff --git a/codes/java/chapter_graph/graph_bfs.java b/codes/java/chapter_graph/graph_bfs.java
index bc58ae12a..ffcf6d0da 100644
--- a/codes/java/chapter_graph/graph_bfs.java
+++ b/codes/java/chapter_graph/graph_bfs.java
@@ -7,7 +7,7 @@
 package chapter_graph;
 
 import java.util.*;
-import include.*;
+import utils.*;
 
 public class graph_bfs {
     /* 广度优先遍历 BFS */
diff --git a/codes/java/chapter_graph/graph_dfs.java b/codes/java/chapter_graph/graph_dfs.java
index 8182fbe70..035b3fbec 100644
--- a/codes/java/chapter_graph/graph_dfs.java
+++ b/codes/java/chapter_graph/graph_dfs.java
@@ -7,7 +7,7 @@
 package chapter_graph;
 
 import java.util.*;
-import include.*;
+import utils.*;
 
 public class graph_dfs {
     /* 深度优先遍历 DFS 辅助函数 */
diff --git a/codes/java/chapter_hashing/hash_map.java b/codes/java/chapter_hashing/hash_map.java
index 0dd400b32..469cf5a5d 100644
--- a/codes/java/chapter_hashing/hash_map.java
+++ b/codes/java/chapter_hashing/hash_map.java
@@ -7,7 +7,7 @@
 package chapter_hashing;
 
 import java.util.*;
-import include.*;
+import utils.*;
 
 public class hash_map {
     public static void main(String[] args) {
diff --git a/codes/java/chapter_heap/heap.java b/codes/java/chapter_heap/heap.java
index 13b7ab647..86679d829 100644
--- a/codes/java/chapter_heap/heap.java
+++ b/codes/java/chapter_heap/heap.java
@@ -6,7 +6,7 @@
 
 package chapter_heap;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 public class heap {
diff --git a/codes/java/chapter_heap/my_heap.java b/codes/java/chapter_heap/my_heap.java
index 03ff3c320..f136dbb85 100644
--- a/codes/java/chapter_heap/my_heap.java
+++ b/codes/java/chapter_heap/my_heap.java
@@ -6,7 +6,7 @@
 
 package chapter_heap;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 /* 大顶堆 */
diff --git a/codes/java/chapter_searching/hashing_search.java b/codes/java/chapter_searching/hashing_search.java
index 0ba50db14..9e5a479f7 100644
--- a/codes/java/chapter_searching/hashing_search.java
+++ b/codes/java/chapter_searching/hashing_search.java
@@ -6,7 +6,7 @@
 
 package chapter_searching;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 public class hashing_search {
diff --git a/codes/java/chapter_searching/linear_search.java b/codes/java/chapter_searching/linear_search.java
index 1a4ffa626..4dd93eb15 100644
--- a/codes/java/chapter_searching/linear_search.java
+++ b/codes/java/chapter_searching/linear_search.java
@@ -6,7 +6,7 @@
 
 package chapter_searching;
 
-import include.*;
+import utils.*;
 
 public class linear_search {
     /* 线性查找（数组） */
diff --git a/codes/java/chapter_stack_and_queue/linkedlist_stack.java b/codes/java/chapter_stack_and_queue/linkedlist_stack.java
index 0e0ec73c9..b214596b8 100644
--- a/codes/java/chapter_stack_and_queue/linkedlist_stack.java
+++ b/codes/java/chapter_stack_and_queue/linkedlist_stack.java
@@ -7,7 +7,7 @@
 package chapter_stack_and_queue;
 
 import java.util.*;
-import include.*;
+import utils.*;
 
 /* 基于链表实现的栈 */
 class LinkedListStack {
diff --git a/codes/java/chapter_tree/avl_tree.java b/codes/java/chapter_tree/avl_tree.java
index aea19fa5c..967483fbd 100644
--- a/codes/java/chapter_tree/avl_tree.java
+++ b/codes/java/chapter_tree/avl_tree.java
@@ -6,7 +6,7 @@
 
 package chapter_tree;
 
-import include.*;
+import utils.*;
 
 /* AVL 树 */
 class AVLTree {
diff --git a/codes/java/chapter_tree/binary_search_tree.java b/codes/java/chapter_tree/binary_search_tree.java
index 1806c0ca7..056542294 100644
--- a/codes/java/chapter_tree/binary_search_tree.java
+++ b/codes/java/chapter_tree/binary_search_tree.java
@@ -7,7 +7,7 @@
 package chapter_tree;
 
 import java.util.*;
-import include.*;
+import utils.*;
 
 /* 二叉搜索树 */
 class BinarySearchTree {
diff --git a/codes/java/chapter_tree/binary_tree.java b/codes/java/chapter_tree/binary_tree.java
index d71e1f8d2..1f4d2c354 100644
--- a/codes/java/chapter_tree/binary_tree.java
+++ b/codes/java/chapter_tree/binary_tree.java
@@ -6,7 +6,7 @@
 
 package chapter_tree;
 
-import include.*;
+import utils.*;
 
 public class binary_tree {
     public static void main(String[] args) {
diff --git a/codes/java/chapter_tree/binary_tree_bfs.java b/codes/java/chapter_tree/binary_tree_bfs.java
index 2fb060ad8..cdf57ac68 100644
--- a/codes/java/chapter_tree/binary_tree_bfs.java
+++ b/codes/java/chapter_tree/binary_tree_bfs.java
@@ -6,7 +6,7 @@
 
 package chapter_tree;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 public class binary_tree_bfs {
diff --git a/codes/java/chapter_tree/binary_tree_dfs.java b/codes/java/chapter_tree/binary_tree_dfs.java
index e04c691cd..b11c64a75 100644
--- a/codes/java/chapter_tree/binary_tree_dfs.java
+++ b/codes/java/chapter_tree/binary_tree_dfs.java
@@ -6,7 +6,7 @@
 
 package chapter_tree;
 
-import include.*;
+import utils.*;
 import java.util.*;
 
 public class binary_tree_dfs {
diff --git a/codes/java/include/ListNode.java b/codes/java/include/ListNode.java
deleted file mode 100755
index ee65d0ede..000000000
--- a/codes/java/include/ListNode.java
+++ /dev/null
@@ -1,36 +0,0 @@
-/**
- * File: ListNode.java
- * Created Time: 2022-11-25
- * Author: Krahets (krahets@163.com)
- */
-
-package include;
-
-/* Definition for a singly-linked list node */
-public class ListNode {
-    public int val;
-    public ListNode next;
-
-    public ListNode(int x) {
-        val = x;
-    }
-
-    /* Generate a linked list with an array */
-    public static ListNode arrToLinkedList(int[] arr) {
-        ListNode dum = new ListNode(0);
-        ListNode head = dum;
-        for (int val : arr) {
-            head.next = new ListNode(val);
-            head = head.next;
-        }
-        return dum.next;
-    }
-
-    /* Get a list node with specific value from a linked list */
-    public static ListNode getListNode(ListNode head, int val) {
-        while (head != null && head.val != val) {
-            head = head.next;
-        }
-        return head;
-    }
-}
diff --git a/codes/java/include/PrintUtil.java b/codes/java/include/PrintUtil.java
deleted file mode 100755
index 8dd576e7e..000000000
--- a/codes/java/include/PrintUtil.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/**
- * File: PrintUtil.java
- * Created Time: 2022-11-25
- * Author: Krahets (krahets@163.com)
- */
-
-package include;
-
-import java.util.*;
-
-class Trunk {
-    Trunk prev;
-    String str;
-
-    Trunk(Trunk prev, String str) {
-        this.prev = prev;
-        this.str = str;
-    }
-};
-
-public class PrintUtil {
-
-    /* Print a matrix (Array) */
-    public static <T> void printMatrix(T[][] matrix) {
-        System.out.println("[");
-        for (T[] row : matrix) {
-            System.out.println("  " + row + ",");
-        }
-        System.out.println("]");
-    }
-
-    /* Print a matrix (List) */
-    public static <T> void printMatrix(List<List<T>> matrix) {
-        System.out.println("[");
-        for (List<T> row : matrix) {
-            System.out.println("  " + row + ",");
-        }
-        System.out.println("]");
-    }
-
-    /* Print a linked list */
-    public static void printLinkedList(ListNode head) {
-        List<String> list = new ArrayList<>();
-        while (head != null) {
-            list.add(String.valueOf(head.val));
-            head = head.next;
-        }
-        System.out.println(String.join(" -> ", list));
-    }
-
-    /**
-     * The interface of the tree printer
-     * This tree printer is borrowed from TECHIE DELIGHT
-     * https://www.techiedelight.com/c-program-print-binary-tree/
-     */
-    public static void printTree(TreeNode root) {
-        printTree(root, null, false);
-    }
-
-    /* Print a binary tree */
-    public static void printTree(TreeNode root, Trunk prev, boolean isLeft) {
-        if (root == null) {
-            return;
-        }
-
-        String prev_str = "    ";
-        Trunk trunk = new Trunk(prev, prev_str);
-
-        printTree(root.right, trunk, true);
-
-        if (prev == null) {
-            trunk.str = "———";
-        } else if (isLeft) {
-            trunk.str = "/———";
-            prev_str = "   |";
-        } else {
-            trunk.str = "\\———";
-            prev.str = prev_str;
-        }
-
-        showTrunks(trunk);
-        System.out.println(" " + root.val);
-
-        if (prev != null) {
-            prev.str = prev_str;
-        }
-        trunk.str = "   |";
-
-        printTree(root.left, trunk, false);
-    }
-
-    /* Helper function to print branches of the binary tree */
-    public static void showTrunks(Trunk p) {
-        if (p == null) {
-            return;
-        }
-
-        showTrunks(p.prev);
-        System.out.print(p.str);
-    }
-
-    /* Print a hash map */
-    public static <K, V> void printHashMap(Map<K, V> map) {
-        for (Map.Entry<K, V> kv : map.entrySet()) {
-            System.out.println(kv.getKey() + " -> " + kv.getValue());
-        }
-    }
-
-    /* Print a heap (PriorityQueue) */
-    public static void printHeap(Queue<Integer> queue) {
-        List<Integer> list = new ArrayList<>(queue);
-        System.out.print("堆的数组表示：");
-        System.out.println(list);
-        System.out.println("堆的树状表示：");
-        TreeNode root = TreeNode.listToTree(list);
-        printTree(root);
-    }
-}
diff --git a/codes/java/include/TreeNode.java b/codes/java/include/TreeNode.java
deleted file mode 100644
index de583ff10..000000000
--- a/codes/java/include/TreeNode.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/**
- * File: TreeNode.java
- * Created Time: 2022-11-25
- * Author: Krahets (krahets@163.com)
- */
-
-package include;
-
-import java.util.*;
-
-/* Definition for a binary tree node. */
-public class TreeNode {
-    public int val; // 节点值
-    public int height; // 节点高度
-    public TreeNode left; // 左子节点引用
-    public TreeNode right; // 右子节点引用
-
-    public TreeNode(int x) {
-        val = x;
-    }
-
-    /* Generate a binary tree given an array */
-    public static TreeNode listToTree(List<Integer> list) {
-        int size = list.size();
-        if (size == 0)
-            return null;
-
-        TreeNode root = new TreeNode(list.get(0));
-        Queue<TreeNode> queue = new LinkedList<>() {{ add(root); }};
-        int i = 0;
-        while (!queue.isEmpty()) {
-            TreeNode node = queue.poll();
-            if (++i >= size)
-                break;
-            if (list.get(i) != null) {
-                node.left = new TreeNode(list.get(i));
-                queue.add(node.left);
-            }
-            if (++i >= size)
-                break;
-            if (list.get(i) != null) {
-                node.right = new TreeNode(list.get(i));
-                queue.add(node.right);
-            }
-        }
-        return root;
-    }
-
-    /* Serialize a binary tree to a list */
-    public static List<Integer> treeToList(TreeNode root) {
-        List<Integer> list = new ArrayList<>();
-        if (root == null)
-            return list;
-        Queue<TreeNode> queue = new LinkedList<>() {{ add(root); }};
-        while (!queue.isEmpty()) {
-            TreeNode node = queue.poll();
-            if (node != null) {
-                list.add(node.val);
-                queue.add(node.left);
-                queue.add(node.right);
-            } else {
-                list.add(null);
-            }
-        }
-        return list;
-    }
-}
diff --git a/codes/java/include/Vertex.java b/codes/java/include/Vertex.java
deleted file mode 100644
index 5696a2fe9..000000000
--- a/codes/java/include/Vertex.java
+++ /dev/null
@@ -1,36 +0,0 @@
-/**
- * File: Vertex.java
- * Created Time: 2023-02-15
- * Author: Krahets (krahets@163.com)
- */
-
-package include;
-
-import java.util.*;
-
-/* 顶点类 */
-public class Vertex {
-    public int val;
-
-    public Vertex(int val) {
-        this.val = val;
-    }
-
-    /* 输入值列表 vals ，返回顶点列表 vets */
-    public static Vertex[] valsToVets(int[] vals) {
-        Vertex[] vets = new Vertex[vals.length];
-        for (int i = 0; i < vals.length; i++) {
-            vets[i] = new Vertex(vals[i]);
-        }
-        return vets;
-    }
-
-    /* 输入顶点列表 vets ，返回值列表 vals */
-    public static List<Integer> vetsToVals(List<Vertex> vets) {
-        List<Integer> vals = new ArrayList<>();
-        for (Vertex vet : vets) {
-            vals.add(vet.val);
-        }
-        return vals;
-    }
-}
diff --git a/docs/chapter_backtracking/permutations_problem.md b/docs/chapter_backtracking/permutations_problem.md
index 0edfde64d..c09ce9803 100644
--- a/docs/chapter_backtracking/permutations_problem.md
+++ b/docs/chapter_backtracking/permutations_problem.md
@@ -2,7 +2,7 @@
 
 全排列问题是回溯算法的一个典型应用。它的定义是在给定一个集合（如一个数组或字符串）的情况下，找出这个集合中元素的所有可能的排列。
 
-如下表所示，展示了输入数组和对应的所有排列。
+如下表所示，列举了几个示例数组和其对应的所有排列。
 
 <div class="center-table" markdown>