C++ program to implement Hash Table

#include <iostream.h>
#include <stdlib.h>
#include<constream.h>
template<class E, class K>
class HashTable {
public:
HashTable(int divisor = 11);
~HashTable() {delete [] ht;
delete [] empty;}
int Search(const K& k, E& e) const;
HashTable<E,K>& Insert(const E& e);
void Output();// output the hash table
void del(E e);
private:
int hSearch(const K& k) const;
int D; // hash function divisor
E *ht; // hash table array
int *empty; // 1D array
};
template<class E, class K>
HashTable<E,K>::HashTable(int divisor)
{// Constructor.
D = divisor;
ht = new E [D];
empty = new int [D];
 
for (int i = 0; i < D; i++)
empty[i] = 1;
}
template<class E, class K>
int HashTable<E,K>::hSearch(const K& k) const
{
int i = k % D;  
int j = i;     
do {
if (empty[j] || ht[j] == k) return j;
j = (j + 1) % D;  // next bucket
} while (j != i); // returned to home?
return j;  // table full
}
template<class E, class K>
void HashTable<E,K>::del(E e)
{
int b=hSearch(e);
if( !empty[b] && ht[b]==e)
{
ht[b]=0;
empty[b]=1;
}
else
cout<<"element not found";
 
}
template<class E, class K>
int HashTable<E,K>::Search(const K& k, E& e) const
{
int b = hSearch(k);
if (empty[b] || ht[b] != k) return 0;
e = ht[b];
return 1;
}
template<class E, class K>
HashTable<E,K>& HashTable<E,K>::Insert(const E& e)
{// Hash table insert.
K k = e; // extract key
int b = hSearch(k);
if (empty[b]) {empty[b] = 0;
ht[b] = e;
return *this;
 
}
if (ht[b] == k) { cout<<"bad input"; return *this; } // duplicate
cout<<"No memory";// table full
return *this;
}
 
template<class E, class K>
void HashTable<E,K>::Output()
{
cout<<endl;
for (int i = 0; i< D; i++) {
if (empty[i]) cout << "0 ";
else cout << ht[i]<<" ";}
cout<<endl;
}
class element {
friend void main(void);
public:
operator long() const {return key;}
private:
int data;
long key;
};
void main(void)
{
clrscr();
HashTable<int , int > h(11);
int e;
e = 80;
h.Insert(e);
e = 40;
h.Insert(e);
e = 65;
h.Insert(e);
cout<<"After inserting 80,40,65:";
h.Output();
cout<<endl;
h.del(40);
cout<<"After deleting 40:";
h.Output();
cout<<endl;
e = 58;
h.Insert(e);
e = 24;
h.Insert(e);
cout<<"after appending 58, 24:";
h.Output();
cout<<"Trying to delete element 25:";
h.del(25);
h.Output();
e = 2;
h.Insert(e);
e = 13;
h.Insert(e);
e = 46;
h.Insert(e);
e = 16;
h.Insert(e);
e = 7;
h.Insert(e);
e = 21;
h.Insert(e);
h.Insert(10);
cout <<"After inserting more values:" << endl;
h.Output();
e = 99;
cout<<"trying to insert 99:";
h.Insert(e);
h.Output();
getch();
}
Editorial Team
Editorial Team

We are a group of young techies trying to provide the best study material for all Electronic and Computer science students. We are publishing Microcontroller projects, Basic Electronics, Digital Electronics, Computer projects and also c/c++, java programs.

Leave a Reply

Your email address will not be published. Required fields are marked *

Get the latest updates on your inbox

Be the first to receive the latest updates from Codesdoc by signing up to our email subscription.

    StudentProjects.in