HashTable-with-template-expanded

// ConsoleApplication1.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include "pch.h"
#include <iostream>
#include <string>

template <typename K, typename V>
struct Node
{
    K key;
    V value;

    Node<K, V> *next;

    Node(K k, V v)
    {
        key = k;
        value = v;
        next = nullptr;
    }
};

template <typename K, typename V>
struct HashTable
{
    int partitions_size;
    Node<K, V> **partitions;

    HashTable(int ps)
    {
        partitions_size = ps;

        partitions = new Node<K, V> *[partitions_size];

        for (int i = 0; i < partitions_size; i++)
        {
            partitions[i] = nullptr;
        }
    }

    ~HashTable()
    {
        delete[] partitions;
    }

    void insert(K key, V value)
    {
        int hash = hash_function(key);

        if (partitions[hash] == nullptr)
        {
            partitions[hash] = new Node<K, V>(key, value);
        }
        else
        {
            Node<K, V> *p = partitions[hash];

            while (p->next != nullptr)
            {
                p = p->next;
            }

            p->next = new Node<K, V>(key, value);
        }
    }

    void display()
    {
        int ct = 0;

        for (int i = 0; i < partitions_size; i++)
        {
            int c = 0;

            std::cout << "partitia " << i << ": ";

            if (partitions[i] == nullptr)
            {
                std::cout << "(empty) ";
            }
            else
            {
                Node<K, V> *p = partitions[i];

                while (p != nullptr)
                {
                    c++;

                    std::cout << "(k: " << p->key << ", v: " << p->value << ") ";

                    p = p->next;
                }

                c = c - 1;
            }

            std::cout << "- " << c << " coliziuni" << std::endl;

            ct += c;
        }

        std::cout << ct << " coliziuni in total" << std::endl;
    }

    int hash_function(int key)
    {
        return key % partitions_size;
    }

    int hash_function(std::string key)
    {
        int hash = 0;

        for (int i = 0; i < key.length(); i++)
        {
            hash = hash ^ key[i];
        }

        return hash % partitions_size;
    }
};

int main()
{
    HashTable<int, std::string> test1(5);

    test1.insert(1, "value 1");
    test1.insert(2, "value 2");
    test1.insert(3, "value 3");

    test1.display();

    HashTable<std::string, std::string> test2(5);

    test2.insert("key 1", "value 1");
    test2.insert("key 2", "value 2");
    test2.insert("key 3", "value 3");

    test2.display();
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

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