*** THIS CODE IS FOR INT ONLY, I NEED TO IMPLEMENT FOR STRINGS #include<iostream

ID: 3710661 • Letter: #

Question

*** THIS CODE IS FOR INT ONLY, I NEED TO IMPLEMENT FOR STRINGS

#include<iostream>

#include<cstdlib>

#include<string>

#include<cstdio>

using namespace std;

const int TABLE_SIZE = 128;

* HashEntry Class Declaration

class HashEntry

{

public:

int key;

int value;

HashEntry(int key, int value)

{

this->key = key;

this->value = value;

}

};

* HashMap Class Declaration

class HashMap

{

private:

HashEntry **table;

public:

HashMap()

{

table = new HashEntry * [TABLE_SIZE];

for (int i = 0; i< TABLE_SIZE; i++)

{

table[i] = NULL;

}

* Hash Function

int HashFunc(int key)

{

return key % TABLE_SIZE;

}

* Insert Element at a key

void Insert(int key, int value)

{

int hash = HashFunc(key);

while (table[hash] != NULL && table[hash]->key != key)

{

hash = HashFunc(hash + 1);

}

if (table[hash] != NULL)

delete table[hash];

table[hash] = new HashEntry(key, value);

}

* Search Element at a key

int Search(int key)

{

int hash = HashFunc(key);

while (table[hash] != NULL && table[hash]->key != key)

{

hash = HashFunc(hash + 1);

}

if (table[hash] == NULL)

return -1;

else

return table[hash]->value;

}

* Remove Element at a key

void Remove(int key)

{

int hash = HashFunc(key);

while (table[hash] != NULL)

{

if (table[hash]->key == key)

break;

hash = HashFunc(hash + 1);

}

if (table[hash] == NULL)

{

cout<<"No Element found at key "<<key<<endl;

return;

}

else

{

delete table[hash];

}

cout<<"Element Deleted"<<endl;

}

~HashMap()

{

for (int i = 0; i < TABLE_SIZE; i++)

{

if (table[i] != NULL)

delete table[i];

delete[] table;

}

};

int main()

{

HashMap hash;

int key, value;

int choice;

while (true)

{

cout<<" ----------------------"<<endl;

cout<<"Operations on Hash Table"<<endl;

cout<<" ----------------------"<<endl;

cout<<"1.Insert element into the table"<<endl;

cout<<"2.Search element from the key"<<endl;

cout<<"3.Delete element at a key"<<endl;

cout<<"4.Exit"<<endl;

cout<<"Enter your choice: ";

cin>>choice;

switch(choice)

{

case 1:

cout<<"Enter 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<<"Enter key of the element to be searched: ";

cin>>key;

if (hash.Search(key) == -1)

{

cout<<"No element found at key "<<key<<endl;

continue;

}

else

{

cout<<"Element at key "<<key<<" : ";

cout<<hash.Search(key)<<endl;

}

break;

case 3:

cout<<"Enter key of the element to be deleted: ";

cin>>key;

hash.Remove(key);

break;

case 4:

exit(1);

default:

cout<<" Enter correct option ";

}

return 0;

}

Task 1: HardCode a C Hash Table that Will Accept a Key as String and Map to String Value. First Name Jane" "John" "Susan" Last Name "Smith" "Do" "Collins" "Rodgers" Jones" "Wright" "Bader" "Eric" "Mike" Create Methods to Insert: insert(key, value) insert("First", "Last") Findvalue("First")-> Method will return value Delete("First") - Method will delete key and value

Explanation / Answer

#include<iostream>
#include<cstdlib>
#include<string>
#include<cstdio>
using namespace std;
const int TABLE_SIZE = 128;

/*
* HashEntry Class Declaration
*/
class HashEntry
{
public:
// To store key value as first name
string keyFirstName;
// To store the value as last name
string valueLastName;

// Parameterized constructor to assign parameter values to data member
HashEntry(string keyFirstName, string valueLastName)
{
this->keyFirstName = keyFirstName;
this->valueLastName = valueLastName;
}// End of constructor
};// End of class

/*
* HashMap Class Declaration
*/
class HashMap
{
private:
// Creates a pointer to pointer type of HashEntry class
HashEntry **table;
public:
// Default constructor
HashMap()
{
// Dynamically allocates memory to table of size TABLE_SIZE which is 128
table = new HashEntry * [TABLE_SIZE];

// Loops till TABLE_SIZE
for (int i = 0; i < TABLE_SIZE; i++)
// Assigns NULL to each element
table[i] = NULL;
}// End of function

/*
* Hash Function
*/
int HashFunc(int key)
{
// Returns remainder
return key % TABLE_SIZE;
}// End of function

/*
* Insert Element at a key
*/
void Insert(string key, string value)
{
// Calls the function to get the position based on the first character of key
int hash = HashFunc((int)key.at(0));

// Loops till table's hash index position is not NULL and table's keyFirstName is not equals to parameter key
while (table[hash] != NULL && table[hash]->keyFirstName != key)
// Calls the function with next of hash value
hash = HashFunc(hash + 1);

// Checks if table's hash index position is not null
if (table[hash] != NULL)
// Delete the table's hash index position data
delete table[hash];

// Creates a new object of class HashEntry using parameterized constructor and assigns it to table's hash index position
table[hash] = new HashEntry(key, value);
}// End of function

/*
* Search Element at a key
*/
string Search(string key)
{
// Calls the function to get the position based on the first character of key
int hash = HashFunc((int)key.at(0));
// Loops till table's hash index position is not NULL and table's keyFirstName is not equals to parameter key
while (table[hash] != NULL && table[hash]->keyFirstName != key)
// Calls the function with next of hash value
hash = HashFunc(hash + 1);

// Checks if table's hash index position is null then returns null
if (table[hash] == NULL)
return " ";
// Otherwise
else
// returns the table's hash index position data
return table[hash]->valueLastName;
}// End of function

/*
* Remove Element at a key
*/
void Remove(string key)
{
// Calls the function to get the position based on the first character of key
int hash = HashFunc((int)key.at(0));

// Loops till table's hash index position is not NULL
while (table[hash] != NULL)
{
// Checks if table's keyFirstName is equals to parameter key then come out of the loop
if (table[hash]->keyFirstName == key)
break;
// Otherwise, Calls the function with next of hash value
hash = HashFunc(hash + 1);
}// End of while loop

// Checks if table's hash index position is null then key not found
if (table[hash] == NULL)
{
cout<<"No Element found at key "<<key<<endl;
return;
}// End of if condition

// Otherwise, key found
else

{
// Delete the key located at table's hash index position
delete table[hash];

// Assign null to the deleted position

table[hash] = NULL;

}

cout<<"Element Deleted"<<endl;
}// End of function

// Destructor definition
~HashMap()
{
// Loops till TABLE_SIZE
for (int i = 0; i < TABLE_SIZE; i++)
{
// Checks if table's i index position is not NULL
if (table[i] != NULL)
// Delete the data
delete table[i];
// Delete the complete table
delete[] table;
}// End of for loop
}// End of destructor
};// End of class

// main function definition
int main()
{
// Creates an object of class HashMap
HashMap hash;
// To store the key and value entered by the user
string key, value;
// To store user choice
int choice;

// Loops till user choice is not 4
while (true)
{
// Displays menu
cout<<" ----------------------"<<endl;
cout<<"Operations on Hash Table"<<endl;
cout<<" ----------------------"<<endl;
cout<<"1.Insert element into the table"<<endl;
cout<<"2.Search element from the key"<<endl;
cout<<"3.Delete element at a key"<<endl;
cout<<"4.Exit"<<endl;
// Accepts user choice
cout<<"Enter your choice: ";
cin>>choice;
// Checks the choice using switch and calls appropriate function
switch(choice)
{
case 1:
cout<<"Enter First name as value to be inserted: ";
cin>>value;
cout<<"Enter Last name as key at which element to be inserted: ";
cin>>key;
hash.Insert(key, value);
break;
case 2:
cout<<"Enter Last name as key of the element to be searched: ";
cin>>key;
if (hash.Search(key) == " ")
{
cout<<"No element found at key "<<key<<endl;
continue;
}
else
{
cout<<"Element at key "<<key<<" : ";
cout<<hash.Search(key)<<endl;
}
break;
case 3:
cout<<"Enter Last name as key of the element to be deleted: ";
cin>>key;
hash.Remove(key);
break;
case 4:
exit(1);
default:
cout<<" Enter correct option ";
}// End of switch - case
}// End of while loop
return 0;
}// End of main function

Sample Output: