Question

This week you worked with hash tables and a variety of ways to handle collisions. For this lab, please implement a hash table that uses a linked list to handle chaining for collision avoidance. You can be creative with your implementation, what I will grade on this lab is your effective hash table implementation ( linked list and chaining ).

Answer 1

Following is the required code:

#include<iostream>
#include<cstdlib>
#include<string>
#include<cstdio>
using namespace std;
class node
{
public:
int key;
int value;
node* next;
node(int key, int value)
{
this->key = key;
this->value = value;
this->next = NULL;
}
};
class map
{
private:
node** hash_table;
public:
map()
{
hash_table = new node*[100];
for (int i = 0; i < 100; i++)
hash_table[i] = NULL;
}
~map()
{
for (int i = 0; i < 100; ++i)
{
node* add_e = hash_table[i];
while (add_e != NULL)
{
node* previous = add_e;
add_e = add_e->next;
delete previous;
}
}
delete[] hash_table;
}
int hash_function(int key)
{
return key % 100;
}
void Insert(int key, int value)
{
int hash_value_e = hash_function(key);
node* previous = NULL;
node* add_e = hash_table[hash_value_e];
while (add_e != NULL)
{
previous = add_e;
add_e = add_e->next;
}
if (add_e == NULL)
{
add_e = new node(key, value);
if (previous == NULL)
{
hash_table[hash_value_e] = add_e;
}
else
{
previous->next = add_e;
}
}
else
{
add_e->value = value;
}
}
int search_e(int key)
{
bool flag = false;
int hash_value_e = hash_function(key);
node* add_e = hash_table[hash_value_e];
while (add_e != NULL)
{
if (add_e->key == key)
{
cout<<add_e->value<<" ";
flag = true;
}
add_e = add_e->next;
}
if (!flag)
return -1;
}
};
int main()
{
map hash;
int key, value;
int ch;
while (1)
{
cout<<"\n1.Insert element into the table"<<endl;
cout<<"2.search_e element from the key"<<endl;
cout<<"3.Exit"<<endl;
cout<<"Enter your choice: ";
cin>>ch;
switch(ch)
{
case 1:
cout<<"\nEnter element to be inserted: ";
cin>>value;
cout<<"Enter key at which element to be inserted: ";
cin>>key;
hash.Insert(key, value);
break;
case 2:
cout<<"\nEnter key of the element to be searched: ";
cin>>key;
cout<<"Element at key "<<key<<" : ";
if (hash.search_e(key) == -1)
{
cout<<"No element found at key "<<key<<endl;
continue;
}
break;
case 3:
exit(1);
default:
cout<<"\nEnter correct option\n";
}
}
return 0;
}

The output is shown below: