哈希表2

哈希表的初始化

void HashInit(HashTable* ht, HashFunc func)
{
    if(ht == NULL)
    {
        return;
    }
    ht -> size = 0;
    ht -> func = func;
    size_t i = 0;
    for(; i < MaxSize; i++)
    {
        ht -> data[i] = NULL;
    }
}

哈希表的結點創建

HashElem* CreateHashElemNode(KeyType key, ValueType value)
{
    HashElem* new_node = (HashElem*)malloc(sizeof(HashElem));
    new_node -> key = key;
    new_node -> value = value;
    new_node -> next = NULL;
    return new_node;
}

void DestroyHashElemNode(HashElem* node)
{
    if(node == NULL)
    {
        return;
    }
    free(node);
}

哈希表的銷燬

void HashDestroy(HashTable* ht)
{
    if(ht == NULL)
    {
        return;
    }
    ht -> size = 0;
    ht -> func = NULL;
    size_t i = 0;
    for(; i < MaxSize; i++)
    {
        HashElem* cur = ht -> data[i];
        while(cur != NULL)
        {
            HashElem* next = cur -> next;
            DestroyHashElemNode(cur);
            cur = next;
        }
    }
}

哈希表的查找

int HashBucketFind(HashElem* node, KeyType key)
{
    if(node == NULL)
    {
        return 0;
    }
    HashElem* cur = node;
    while(cur != NULL)
    {
        if(cur -> key == key)
        {
            return 1;
        }
        cur = cur -> next;
    }
    return 0;
}

int HashFind(HashTable* ht, KeyType key, ValueType* value)
{
    if(ht == NULL || value == NULL)
    {
        return 0;
    }
    size_t offset = ht -> func(key);
    HashElem* cur = ht -> data[offset];
    while(cur != NULL)
    {
        if(cur -> key == key)
        {
            *value = cur -> value;
            return 1;
        }
        cur = cur -> next;
    }
    return 0;
}

int HashBucketFindEx(HashElem* node, KeyType key, HashElem** cur_node, HashElem** prev_node)
{
    if(node == NULL)
    {
        return 0;
    }
    if(cur_node == NULL || prev_node == NULL)
    {
        return 0;
    }
    HashElem* cur = node;
    HashElem* prev = NULL;
    while(cur != NULL)
    {
        prev = cur;
        if(cur -> key == key)
        {
            break;
        }
        cur = cur -> next;
    }
    if(cur == NULL)
    {
        return 0;
    }
    *cur_node = cur;
    *prev_node = prev;
    return 1;
}

哈希表的插入

void HashInsert(HashTable* ht, KeyType key, ValueType value)
{
    if(ht == NULL)
    {
        return;
    }
    size_t offset = ht -> func(key);
    HashElem* new_node = CreateHashElemNode(key, value);
    int ret = HashBucketFind(ht -> data[offset], key);
    if(ret == 1)
    {
        return;
    }
    new_node -> next = ht -> data[offset];
    ht -> data[offset] = new_node;
    ht -> size++;
}

哈希表的刪除

void HashRemove(HashTable* ht, KeyType key)
{
    if(ht == NULL)
    {
        return;
    }
    if(ht -> size == 0)
    {
        return;
    }
    size_t offset = ht -> func(key);
    HashElem* cur = NULL;
    HashElem* prev = NULL;
    int ret = HashBucketFindEx(ht -> data[offset], key, &cur, &prev);
    if(ret == 0)
    {
        return;//沒有找到
    }
    if(prev == NULL)
    {
        ht -> data[offset] = cur -> next;
    }
    else
    {
        prev -> next = cur -> next;
    }
    DestroyHashElemNode(cur);
    cur = NULL;
    ht -> size--;
}