hashtable.h

该程序用ＶＣ实现了一个小型文件压缩与解压缩功能的程序

#ifndef HashTable_H
#define HashTable_H
#include"Seqlist.h"
#include"LinkedList.h"

template<class T>
class HashTable
{
	private:
		int bucketNum;
		SeqList< LinkedList<T> > bucket;

		unsigned long (*hf)(const T& key);
	public:
	HashTable(int nbuckets,
		unsigned long hashf(const T& key));
	~HashTable();

	void Insert(const T& key);
	ListNode<T>* Find(T& key);
	void Delete(const T& key);
	void ClearList(void);
	void Update(const T& key);
	void Summary(char ch[],int freq[],int& m);
	friend ostream& operator << (ostream& os, const HashTable<T>& h);
};

template<class T>
HashTable<T>::HashTable(int nbuckets,
						   unsigned long hashf(const T& key))
						   :bucketNum(nbuckets), bucket(bucketNum),hf(hashf)
{}

template<class T>
HashTable<T>::~HashTable()
{
	ClearList();
}

template<class T>
void HashTable<T>::Insert(const T& key)
{
	int pos = int(hf(key));
	bucket[pos].InsertFront(key);
}

template<class T>
ListNode<T>* HashTable<T>::Find(T& key)
{
	int pos = int(hf(key));          
	int j = bucket[pos].Find(key);   
	return bucket[pos].Locate(j);   
}  

template<class T>
void HashTable<T>::Delete(const T& key)
{
	int pos = int(hf(key));
	bucket[pos].DeleteNode(key);
}

template<class T>
void HashTable<T>::ClearList(void)
{
	for(int i=0;i<bucketNum;i++)
		bucket[i].ClearList();
}

template<class T>
void HashTable<T>::Update(const T& key)
{
	int pos = int(hf(key));
	int j = bucket[pos].Find(key);
	(bucket[pos].Locate(j)->data)++;        
}

template<class T>
ostream& operator << (ostream& os, const HashTable<T>& h)
{
	for(int i=0;i<h.bucketNum;i++)
	{
		if(h.bucket[i].IsEmpty()) {os<<"bucket"<<" "<<i<<endl;continue;}
		os<<"bucket"<<" "<<i<<endl;
		os<<h.bucket[i];
	}
	return os;
}


template<class T>
void HashTable<T>::Summary(char ch[],int freq[],int& m)
{
	int j=0;
	for(int i=0;i<bucketNum;i++)
	{
		
		ListNode<T> *p = bucket[i].header;
		while(p!=NULL){
			ch[j] = (p->data).ch;
			freq[j++] = (p->data).fre;
			p = p->link;
			m++;
		}
	}
}
#endif