Fix some errors of cmake build and add hashing_search.c (#458)

* fix(codes/cpp): Memory leak fix: the space was not freed when pop removed the element.

* fix(codes/cpp): Fix access error when printArray(arr, 0)

* Update PrintUtil.hpp

* fix(codes/c): Fix some errors of cmake build

* feat(codes/c): Add hashing_search.c

---------

Co-authored-by: Yudong Jin <krahets@163.com>

codes/c/CMakeLists.txt

@@ -12,3 +12,4 @@ add_subdirectory(chapter_sorting)
 add_subdirectory(chapter_tree)
 add_subdirectory(chapter_stack_and_queue)
 add_subdirectory(chapter_heap)
+add_subdirectory(chapter_searching)

codes/c/chapter_searching/CMakeLists.txt

@@ -1,2 +1,3 @@
 add_executable(binary_search binary_search.c )
 add_executable(linear_search linear_search.c)
+add_executable(hashing_search hashing_search.c)

codes/c/chapter_searching/hashing_search.c

@@ -0,0 +1,146 @@
+/**
+ * File: hashing_search.c
+ * Created Time: 2023-04-15
+ * Author: Gonglja (glj0@outlook.com)
+ */
+
+#include "../include/include.h"
+
+/* 哈希表 */
+struct hashTable {
+    int key;    // key 为 int 型
+    void* val;  // val 为 void * 型
+    UT_hash_handle hh; // 借助 uthash 实现的哈希表
+};
+
+typedef struct hashTable hashTable;
+
+/* 打印哈希表（当 hashTable 中 val 为 int 型使用这个） */
+void printHashTableVal(hashTable **ht) {
+    struct hashTable *s;
+    for (s = *ht; s != NULL; s = s->hh.next) {
+      printf("key: %d: val: %d\n", s->key, *(int *)(s->val));
+    }
+}
+
+/* 打印哈希表（当 hashTable 中 val 为 ListNode* 型使用这个） */
+void printHashTableLinklist(hashTable **ht) {
+  struct hashTable *s;
+  for (s = *ht; s != NULL; s = s->hh.next) {
+    printf("key: %d: val: %d\n", s->key, ((ListNode *)s->val)->val);
+  }
+}
+
+/* 哈希表查找 */
+hashTable* find(hashTable *ht, int k) {
+    hashTable *s;
+    HASH_FIND_INT(ht, &k, s);
+    return s;
+}
+
+/* 添加 k、v 到哈希表 ht 中，v 为 int 类型 */
+void addInt(hashTable **ht, int k, int v) {
+    hashTable *s;
+    HASH_FIND_INT(*ht, &k, s);
+    if (s == NULL) {
+        s = malloc (sizeof(*s));
+        s->key = k;
+        HASH_ADD_INT(*ht, key, s);
+    }
+    int *tmp = malloc(sizeof(*s->val));
+    *tmp = v;
+    s->val = tmp;
+}
+
+/* 添加 k、v 到哈希表 ht 中，v 为 ListNode* 类型 */
+void addLinkNode(hashTable **ht, int k, ListNode* v) {
+    hashTable *s;
+    HASH_FIND_INT(*ht, &k, s);
+    if (s == NULL) {
+        s = malloc (sizeof(*s));
+        s->key = k;
+        HASH_ADD_INT(*ht, key, s);
+    }
+    s->val = (void *)v;
+}
+
+/* 删除 ht 中所有元素 */
+void deleteAll(hashTable **ht) {
+    hashTable *curr, *tmp;
+    HASH_ITER(hh, *ht, curr, tmp) {
+        HASH_DEL(*ht, curr);
+        free(curr);
+    }
+}
+
+/* 通过 key 访问哈希表，返回 int 类型 */
+int accessInt(hashTable **h, int key) {
+    hashTable *s;
+    int ret=-1;
+    if (s = find(*h, key)) {
+        ret = *(int *)s->val;
+    }
+    return ret;
+}
+
+/* 通过 key 访问哈希表，返回 ListNode* 类型 */
+ListNode* accessLinkNode(hashTable **h, int key) {
+    hashTable *s;
+    ListNode *res=NULL;
+    if (s = find(*h, key)) {
+        res = (ListNode *)s->val;
+    }
+    return res;
+}
+
+/* 哈希查找（数组） */
+int hashingSearchArray(hashTable **ht, int target) {
+    // 哈希表的 key: 目标元素，value: 索引
+    // 若哈希表中无此 key ，返回 -1
+    if (find(*ht, target) == NULL)
+        return -1;
+    return accessInt(ht, target);
+}
+
+/* 哈希查找（链表） */
+ListNode *hashingSearchLinkedList(hashTable **ht, int target) {
+    // 哈希表的 key: 目标节点值，value: 节点对象
+    // 若哈希表中无此 key ，返回 nullptr
+    if (find(*ht, target) == NULL)
+        return NULL;
+    return accessLinkNode(ht, target);
+}
+
+/* Driver Code */
+int main() {
+    int target = 3;
+
+    /* 哈希查找（数组） */
+    int nums[] = {1, 5, 3, 2, 4, 7, 5, 9, 10, 8};
+    // 初始化哈希表
+    hashTable** ht = malloc(sizeof(*ht));
+    *ht = NULL;
+    for (int i = 0; i < sizeof(nums)/sizeof(nums[0]); i++) {
+      addInt(ht, nums[i], i); // key: 元素，value: 索引
+    }
+    int index = hashingSearchArray(ht, target);
+    printf("目标元素 3 的索引 = %d\r\n", index);
+    deleteAll(ht);
+
+    /* 哈希查找（链表） */
+    ListNode *head = arrToLinkedList(nums, sizeof(nums)/sizeof(nums[0]));
+    // 初始化哈希表
+    hashTable** ht1 = malloc(sizeof(*ht));
+    *ht1 = NULL;
+
+    while (head != NULL) {
+        addLinkNode(ht1, head->val, head); // key: 节点值，value: 节点
+        head = head->next;
+    }
+
+    ListNode *node = hashingSearchLinkedList(ht1, target);
+    if (node)
+        printf("目标节点值 3 的对应节点对象为 %#p val: %d\r\n", node, node->val);
+    deleteAll(ht1);
+    return 0;
+}

codes/c/chapter_tree/CMakeLists.txt

@@ -1,5 +1,5 @@
 add_executable(avl_tree avl_tree.c)
-add_executable(binary_search binary_tree.c)
+add_executable(binary_tree binary_tree.c)
 add_executable(binary_tree_bfs binary_tree_bfs.c)
 add_executable(binary_tree_dfs binary_tree_dfs.c)
 add_executable(binary_search_tree binary_search_tree.c)