Project #4 – Hash Table Indexing Solved

The HashTable class
Your hash table should be implemented as an array of MAXHASH objects of class Slot. A Slot contains an integer key (the student's UID), and a value, which can be of any type. The implementaiton of class Slot will be provided for you in the file Slot.h. The value of MAXHASH should initially be #defined to 1000.

Your hash table should accept integer keys, and any type of value. To implement the hash table, you should create a class template called HashTable, implemented inline in the file HashTable.h. Your class should support the following operations (for any class T):

bool HashTable<T::insert(int key, T value, int& collisions) – Insert a new key/value pair into the table. Duplicate keys are not allowed. This function should return true if the key/value pair is successfully inserted into the hash table, and false if the pair could not be inserted (for example, due to a duplicate key already found in the table). If the insertion is successful, the number of collisions occuring during the insert operation should be returned in collisions.

 

bool HashTable<T::remove(int key) – If there is a record with the given key in the hash table, it is deleted and the function returns true; otherwise the function returns false.

 

bool HashTable<T::find(int key, T& value) – If a record with the given key is found in the hash table, the function returns true and a copy of the value is returned in value. Otherwise the function returns false.

 

 float HashTable<T::alpha() ‐ returns the current loading factor, α, of the hash table.

 

Your hash table should also overload operator<< such that cout << myHashTable prints all the key/value pairs in the table, along with their hash table slot, to cout.

 

The hash and probe functions
Because this is a closed hash, you will need both a hash function and a probe function. You are free to implement any hash function you like. For example, you may choose to implement some form of the ELFhash, given in Chapter 9 of your textbook, or any other hash function that will work on integer keys. Remember to cite your source if you use code written by anyone other than yourself!

Your hash should use pseudo-random probing to resolve collisions.

Implementing your database
Your hash table should be used as an index for a database of student records. Each student record should contain the student's last name, first name, UID, major, and year (freshman, sophomore, etc.). Student record objects should be stored in the hash table.

Main program
You should use your student database in a main program that allows a user to insert, search, and delete from the database.

Example program operation

Would you like to (I)nsert or (D)elete a record, or (S)earch for a record, or (Q)uit?

Enter action:  I

Inserting a new record.

Last name:  Doe

First name:  Jane

UID: 1234 Year:  Junior

Record inserted.

 

Would you like to (I)nsert or (D)elete a record, or (S)earch for a record, or (Q)uit?

Enter action:  S

Enter UID to search for: 1234

Searching... record found

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Last name:  Doe

First name:  Jane

UID: 1234

Year:  Junior

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Would you like to (I)nsert or (D)elete a record, or (S)earch for a record, or (Q)uit?

Enter action:  S

Enter UID to search for: 2345 Searching... record not found

 
Would you like to (I)nsert or (D)elete a record, or (S)earch for a record, or (Q)uit?

Enter action:  Q Exiting.