所以我的数据结构应该是一个哈希表,一个链表的数组。在每个链表中都有一个链表。在这些链接列表里面有一本书。一本书包含一本书名,以及一本藏书的链接列表库ID。在另一个结构中访问struct字段
我在链接列表中查找是否存在book->名称时遇到问题。 我知道如何访问所谓的“架子”,它是由:
int index = hashFunction(char* nameOfBook) % this->size;
,然后哈希阵列内搜索找到这样的:
this->chain[index]
但我怎么能访问Book结构一旦我在链接列表中?
在list.h
typedef struct NodeStruct {
void *data;
struct NodeStruct* next;
struct NodeStruct* prev;
} NodeStruct;
typedef struct ListStruct {
NodeStruct* first;
NodeStruct* last;
int elementType;
} ListStruct;
在hash.c:
typedef struct Book {
ListStruct* libID; // Each book has its own list of library IDs
char* name; // Each book has a name.
} Book;
// A hashset contains a linked list of books.
typedef struct HashStruct {
int size;
int load;
ListStruct **chain; //An array of Linked Lists.
} HashStruct;
下面是构造函数:
// Constructor for a new book.
Book *newBook(char* name) {
Book *this = malloc (sizeof (Book));
assert(this != NULL);
this->name = name;
this->libID = malloc(sizeof (ListStruct*));
this->libID = newList(sizeof(int));
return this;
}
HashHandle new_hashset(int size) {
HashHandle tempHash = malloc (sizeof (HashStruct));
assert (tempHash != NULL);
tempHash->size = size;
tempHash->load = 0;
tempHash->chain = malloc (sizeof (ListStruct));
assert(tempHash->chain != NULL);
// Each linked list holds a linked list.
for (int i = 0; i < size; ++i) {
tempHash->chain[i] = newList(sizeof(Book));
}
return tempHash;
}
编辑:我觉得我它得工作。还没有测试过。
bool has_hashset (HashHandle this, char *item) {
//Finds the index to look at.
int index = strhash(item) % this->size;
NodeStruct *cur = this->chain[index]->first;
while (cur != NULL) {
Book *tmp = cur->data;
if (strcmp(tmp->name, item) == 0)
return true;
cur = cur->next;
}
return false;
}
对不起,如果这是非常混乱。顺便说一句,链表的'数据'是通用的。 谢谢!
'for(int i = 0; i chain [i] = newList(sizeof(Book *));}'没有意义。也许:'for(int i = 0; i chain [i] = NULL;}'? –
wildplasser
嗨,为什么不初始化所有的链表?分别初始化每一个更好吗? – Mickey