#ifndef HashTable_SEEN__
#define HashTable_SEEN__
///////    File: HashTable.h    ///////

// Each entry of table has a key which is a string
// The key string is unique: two entries are regarded to
//     be the same if they have the same key
// A function getkey that extracts a key from an entry must
//     also be defined
// Usage:  HashTable<empolyee> ht(n)
//    gives a hash table of employees, size 2^n, [n=8]
//    getkey can return the SS No. for example

#include "List.h"
#define CS const
typedef unsigned Uint;

template <class T>
class HashTable
{ public:
    enum {noe, H_MULT=2640025017u};// no entry and default multiplier
    HashTable(Uint k = 8,          // constructor
               Uint m = H_MULT);
    void put(T& a);                // enters record a
    int get(CS char *key, T& r);   // returns record in rval
    int rid(CS char* key);         // removes a record
    int is_on(char* key);          // checks if record is on table
    Uint length() { return len; }  // returns length of table
    ~HashTable();
  private:
     List<T>** ht;                 // table of linked lists
     Uint hash(CS char*);          // builtin hash function 
     static int on_list            // record on list l?
        (List<T>& l, char* key);
     Uint len;                     // No. of entries on table
     Uint mult;                    // hash multiplier
     Uint bits;                    // hash table 2^bits
};

template <class T>
char* getkey(T& item);             // supplied key function

Uint str_to_u(const char *str);    // common utility function
#endif