double_hash_hash_table.cpp File Reference

Storage mechanism using double-hashed keys. More...

#include <iostream>
#include <memory>
#include <vector>

Include dependency graph for double_hash_hash_table.cpp:

Classes
struct	double_hashing::Entry

Namespaces
namespace	double_hashing
	An implementation of hash table using double hashing algorithm.

Typedefs
using	double_hashing::Entry = struct Entry

Functions
bool	double_hashing::putProber (const Entry &entry, int key)
bool	double_hashing::searchingProber (const Entry &entry, int key)
void	double_hashing::add (int key)
size_t	double_hashing::hashFxn (int key)
	Hash a key. Uses the STL library's std::hash() function.
size_t	double_hashing::otherHashFxn (int key)
	Used for second hash function.
int	double_hashing::doubleHash (int key, bool searching)
	Performs double hashing to resolve collisions.
void	double_hashing::display ()
void	double_hashing::rehash ()
void	double_hashing::remove (int key)
void	double_hashing::addInfo (int key)
void	double_hashing::removalInfo (int key)
int	main ()

Variables
int	double_hashing::notPresent
std::vector< Entry >	double_hashing::table
int	double_hashing::totalSize
int	double_hashing::tomb = -1
int	double_hashing::size
bool	double_hashing::rehashing

Detailed Description

Storage mechanism using double-hashed keys.

Author

achance6

Krishna Vedala

Note

The implementation can be optimized by using OOP style.

Function Documentation

main()

int main

(

void

)

Main program

Returns

0 on success

           {
    int cmd = 0, hash = 0, key = 0;
    std::cout << "Enter the initial size of Hash Table. = ";
    std::cin >> totalSize;
    table = std::vector<Entry>(totalSize);
    bool loop = true;
    while (loop) {
        std::cout << std::endl;
        std::cout << "PLEASE CHOOSE -" << std::endl;
        std::cout << "1. Add key. (Numeric only)" << std::endl;
        std::cout << "2. Remove key." << std::endl;
        std::cout << "3. Find key." << std::endl;
        std::cout << "4. Generate Hash. (Numeric only)" << std::endl;
        std::cout << "5. Display Hash table." << std::endl;
        std::cout << "6. Exit." << std::endl;
        std::cin >> cmd;
        switch (cmd) {
            case 1:
                std::cout << "Enter key to add = ";
                std::cin >> key;
                double_hashing::addInfo(key);
                break;
            case 2:
                std::cout << "Enter key to remove = ";
                std::cin >> key;
                double_hashing::removalInfo(key);
                break;
            case 3: {
                std::cout << "Enter key to search = ";
                std::cin >> key;
                Entry entry = table[double_hashing::doubleHash(key, true)];
                if (entry.key == double_hashing::notPresent) {
                    std::cout << "Key not present";
                }
                break;
            }
            case 4:
                std::cout << "Enter element to generate hash = ";
                std::cin >> key;
                std::cout << "Hash of " << key
                          << " is = " << double_hashing::hashFxn(key);
                break;
            case 5:
                double_hashing::display();
                break;
            default:
                loop = false;
                break;
                // delete[] table;
        }
        std::cout << std::endl;
    }
    return 0;
}

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