分离链表法散列ADT

分离链表法解决冲突的散列表ADT实现

数据结构定义如下：

struct ListNode;
typedef struct ListNode *Position;
struct HashTbl;
typedef struct HashTbl *HashTable;

HashTable InitializeTable(int TableSize);
void DestroyTable(HashTable H);
Position Find(ElementType Key, HashTable H);
void Insert(ElementType Key, HashTable H);

struct ListNode{
    ElementType Element;
    Position Next;
};

typedef Position List;

struct HashTbl{
    int TableSize;
    List *TheLists;
};

初始化散列表实现代码如下：

HashTable InitializeTable(int TableSize){
    HashTable H;
    int i;

    if(TableSize < MinTableSize){
        printf("Table size too small
");
        return NULL;
    }
    H = malloc(sizeof(struct HashTbl));
    H->TableSize = TableSize;
    H->TheLists = malloc(H->TableSize * sizeof(List));
    for(i=0; i<H->TableSize; i++){
        H->TheLists[i] = malloc(sizeof(struct ListNode));
        H->TheLists[i]->Next = NULL;
    }
    return H;    
}

Find的实现代码如下：

Position Find(ElementType Key, HashTable H){
    Position P;
    List L;
    L = H->TheLists[Hash(Key, H->TableSize)];
    P = L->Next;
    while(P!=NULL && P->Element!=Key)
        P = P->Next;
    return P;
}

Insert的实现代码如下：

void Insert(ElementType Key, HashTable H){
    Position Pos, NewCell;
    List L;

    Pos = Find(Key, H);
    if(Pos != NULL){
        NewCell = malloc(sizeof(struct ListNode));
        L = H->TheLists[Hash(Key, H->TableSize)];
        NewCell->Element = Key;
        NewCell->Next = L->Next;
        L->Next = NewCell;
    }
}

Delete的实现代码如下：

void Delete(ElementType Key, HashTable H){
    Position P;
    List L;

    L = H->TheLists[Hash(Key, H->TableSize)];
    while(L->Next!=NULL && L->Next->Element!=Key)
        L = L->Next;
    
    if(L->Next == NULL)
        printf("Key not in the hashtable
");
    else{
        P = L->Next;
        L->Next = P->Next;
        free(P);
    }
}