分离链接散列表的实现

分离链接散列表的类型声明

#ifndef _HashSep_H

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

HashTable InitilizeTable(int TableSize);
void DestroyTable(HashTable H);
Position Find(ElementType Key,HashTable H);
void Insert(ElementType Key,HashTable H);
ElementType Retrieve(Position P);

#endif

struct ListNode
{
    ElementType Element;
    Position Next;
};
struct HashTbl
{
    int TableSize;
    List *TheLists;
};

分离链接散列表的初始化

HashTable InitializeTable(int TableSize)
{
    HashTable H;
    int i;
    
    if(TableSize < MinTableSize)
    {
        Error("Table size too small");
        return NULL;
    }
    H = malloc(sizeof(struct HashTbl));
    if(H == NULL)
        FatalError("Out of space!!!");
    H->TableSize = NextPrime(TableSize);
    H->TheLists = malloc(sizeof(Lisr)*H->TableSize);
    if(H->TheLists == NULL)
        FatalError("Out of space!!!");
    for(i = 0;i < H->TableSize; i++)
    {
        H->TheLists[i] = malloc(sizeof(struct ListNode));
        if(H->TheLists[i] == NULL)
            FatalError("Out of space!!!");
        else
            H->TheLists[i]->Next = NULL;
    }
    return H;
}

分离链接散列表的查找程序

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;
}

分离链接散列表的插入程序

void Insert(ElementType Key,HashTable H)
{
    Position Pos,NewCell;
    List L;
    Pos = Find(Key,H);
    if(Pos == NULL)
    {
        NewCell = malloc(sizeof(struct ListNode));
        if(NewCell == NULL)
            FatalError("Out of space!!!");
        else
        {
            L = H->TheLists[Hash(Key,H->TableSize)];
            NewCell->Next = L->Next;
            NewCell->Element = Key;
            L->Next = NewCell;
        }
    }
}