帮我写一个C++ HashMap的代码

以下是一个C语言实现的HashMap的简单示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define TABLE_SIZE 100

typedef struct Node {
    char* key;
    char* value;
    struct Node* next;
} Node;

typedef struct {
    Node* head;
} Bucket;

typedef struct {
    Bucket* buckets;
} HashMap;

int hash(char* key) {
    int hash = 0;
    int len = strlen(key);
    for (int i = 0; i < len; i++) {
        hash += key[i];
    }
    return hash % TABLE_SIZE;
}

Node* create_node(char* key, char* value) {
    Node* node = (Node*) malloc(sizeof(Node));
    node->key = key;
    node->value = value;
    node->next = NULL;
    return node;
}

void insert(HashMap* map, char* key, char* value) {
    int index = hash(key);
    Node* node = create_node(key, value);
    if (map->buckets[index].head == NULL) {
        map->buckets[index].head = node;
    } else {
        Node* cur = map->buckets[index].head;
        while (cur->next) {
            cur = cur->next;
        }
        cur->next = node;
    }
}

char* search(HashMap* map, char* key) {
    int index = hash(key);
    Node* cur = map->buckets[index].head;
    while (cur) {
        if (strcmp(cur->key, key) == 0) {
            return cur->value;
        }
        cur = cur->next;
    }
    return NULL;
}

void destroy_map(HashMap* map) {
    for (int i = 0; i < TABLE_SIZE; i++) {
        Node* cur = map->buckets[i].head;
        while (cur) {
            Node* temp = cur;
            cur = cur->next;
            free(temp->key);
            free(temp->value);
            free(temp);
        }
    }
    free(map->buckets);
    free(map);
}

int main() {
    HashMap* map = (HashMap*) malloc(sizeof(HashMap));
    map->buckets = (Bucket*) malloc(sizeof(Bucket) * TABLE_SIZE);

    insert(map, "name", "Tom");
    insert(map, "age", "18");
    insert(map, "gender", "male");

    printf("name: %s\n", search(map, "name"));
    printf("age: %s\n", search(map, "age"));
    printf("gender: %s\n", search(map, "gender"));

    destroy_map(map);

    return 0;
}

这个HashMap使用了链表解决冲突，实现了插入和查找操作。当然，这个实现还可以更完善，比如增加删除操作，缩小哈希表空间等等。