1. Remove Pair class from hash coliision code.

2. Fix the comment in my_list code.
3. Add a Q&A to the summary of sorting.

codes/cpp/chapter_array_and_linkedlist/my_list.cpp

@@ -67,7 +67,7 @@ class MyList {
         // 元素数量超出容量时，触发扩容机制
         if (size() == capacity())
             extendCapacity();
-        // 索引 i 以及之后的元素都向后移动一位
+        // 将索引 index 以及之后的元素都向后移动一位
         for (int j = size() - 1; j >= index; j--) {
             nums[j + 1] = nums[j];
         }

codes/cpp/chapter_backtracking/CMakeLists.txt

@@ -5,3 +5,6 @@ add_executable(preorder_traversal_iii_template preorder_traversal_iii_template.c
 add_executable(permutations_i permutations_i.cpp)
 add_executable(permutations_ii permutations_ii.cpp)
 add_executable(n_queens n_queens.cpp)
+add_executable(subset_sum_i_naive subset_sum_i_naive.cpp)
+add_executable(subset_sum_i subset_sum_i.cpp)
+add_executable(subset_sum_ii subset_sum_ii.cpp)

codes/cpp/chapter_graph/graph_adjacency_list.cpp

@@ -87,4 +87,4 @@ class GraphAdjList {
     }
 };
 
-// GraphAdjList 的测试样例在 graph_adjacency_list_test.cpp 文件中
+// 测试样例请见 graph_adjacency_list_test.cpp

codes/cpp/chapter_hashing/CMakeLists.txt

@@ -1,2 +1,6 @@
-add_executable(array_hash_map array_hash_map.cpp)
 add_executable(hash_map hash_map.cpp)
+add_executable(array_hash_map_test array_hash_map_test.cpp)
+add_executable(hash_map_chaining hash_map_chaining.cpp)
+add_executable(hash_map_open_addressing hash_map_open_addressing.cpp)
+add_executable(simple_hash simple_hash.cpp)
+add_executable(built_in_hash built_in_hash.cpp)

codes/cpp/chapter_hashing/array_hash_map.cpp

@@ -107,47 +107,4 @@ class ArrayHashMap {
     }
 };
 
-/* Driver Code */
-int main() {
-    /* 初始化哈希表 */
-    ArrayHashMap map = ArrayHashMap();
-
-    /* 添加操作 */
-    // 在哈希表中添加键值对 (key, value)
-    map.put(12836, "小哈");
-    map.put(15937, "小啰");
-    map.put(16750, "小算");
-    map.put(13276, "小法");
-    map.put(10583, "小鸭");
-    cout << "\n添加完成后，哈希表为\nKey -> Value" << endl;
-    map.print();
-
-    /* 查询操作 */
-    // 向哈希表输入键 key ，得到值 value
-    string name = map.get(15937);
-    cout << "\n输入学号 15937 ，查询到姓名 " << name << endl;
-
-    /* 删除操作 */
-    // 在哈希表中删除键值对 (key, value)
-    map.remove(10583);
-    cout << "\n删除 10583 后，哈希表为\nKey -> Value" << endl;
-    map.print();
-
-    /* 遍历哈希表 */
-    cout << "\n遍历键值对 Key->Value" << endl;
-    for (auto kv : map.pairSet()) {
-        cout << kv->key << " -> " << kv->val << endl;
-    }
-
-    cout << "\n单独遍历键 Key" << endl;
-    for (auto key : map.keySet()) {
-        cout << key << endl;
-    }
-
-    cout << "\n单独遍历值 Value" << endl;
-    for (auto val : map.valueSet()) {
-        cout << val << endl;
-    }
-
-    return 0;
-}
+// 测试样例请见 array_hash_map_test.cpp

codes/cpp/chapter_hashing/array_hash_map_test.cpp

@@ -0,0 +1,52 @@
+/**
+ * File: array_hash_map_test.cpp
+ * Created Time: 2022-12-14
+ * Author: msk397 (machangxinq@gmail.com)
+ */
+
+#include "./array_hash_map.cpp"
+
+/* Driver Code */
+int main() {
+    /* 初始化哈希表 */
+    ArrayHashMap map = ArrayHashMap();
+
+    /* 添加操作 */
+    // 在哈希表中添加键值对 (key, value)
+    map.put(12836, "小哈");
+    map.put(15937, "小啰");
+    map.put(16750, "小算");
+    map.put(13276, "小法");
+    map.put(10583, "小鸭");
+    cout << "\n添加完成后，哈希表为\nKey -> Value" << endl;
+    map.print();
+
+    /* 查询操作 */
+    // 向哈希表输入键 key ，得到值 value
+    string name = map.get(15937);
+    cout << "\n输入学号 15937 ，查询到姓名 " << name << endl;
+
+    /* 删除操作 */
+    // 在哈希表中删除键值对 (key, value)
+    map.remove(10583);
+    cout << "\n删除 10583 后，哈希表为\nKey -> Value" << endl;
+    map.print();
+
+    /* 遍历哈希表 */
+    cout << "\n遍历键值对 Key->Value" << endl;
+    for (auto kv : map.pairSet()) {
+        cout << kv->key << " -> " << kv->val << endl;
+    }
+
+    cout << "\n单独遍历键 Key" << endl;
+    for (auto key : map.keySet()) {
+        cout << key << endl;
+    }
+
+    cout << "\n单独遍历值 Value" << endl;
+    for (auto val : map.valueSet()) {
+        cout << val << endl;
+    }
+
+    return 0;
+}

codes/cpp/chapter_hashing/hash_map_chaining.cpp

@@ -4,18 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../utils/common.hpp"
-
-/* 键值对 */
-struct Pair {
-  public:
-    int key;
-    string val;
-    Pair(int key, string val) {
-        this->key = key;
-        this->val = val;
-    }
-};
+#include "./array_hash_map.cpp"
 
 /* 链式地址哈希表 */
 class HashMapChaining {

codes/cpp/chapter_hashing/hash_map_open_addressing.cpp

@@ -4,16 +4,7 @@
  * Author: Krahets (krahets@163.com)
  */
 
-#include "../utils/common.hpp"
-
-/* 键值对 */
-struct Pair {
-    int key;
-    string val;
-
-    Pair(int k, string v) : key(k), val(v) {
-    }
-};
+#include "./array_hash_map.cpp"
 
 /* 开放寻址哈希表 */
 class HashMapOpenAddressing {