Algo2

#include <iostream>
#include <ctime>
#include <stdio.h>
#include <stdlib.h>
using namespace std;
class Node
{
    public:
    int key;
    double d_variable;
    char ch_variable;
    Node** forward;
    //node constructor
    Node(int key, int level)
    {
        this->key = key;
        this->d_variable = rand();
        this->ch_variable = 'T';
        forward = new Node * [level + 1];
        for (int i = 0; i < level + 1; i++)
        {
            forward[i] = NULL;
        }
    }
};
class Skiplist
{
    public:
    Node* HEADER;
    unsigned int MAX_LEVEL;
    int level;
    float PROB;

    //constructor
    Skiplist(int MAX_LEVEL,float PROB)
    {
        this->MAX_LEVEL = MAX_LEVEL;
        this->PROB = PROB;
        level =0;
        HEADER = new Node(-1,MAX_LEVEL);
    }

    //creates new node
    Node* createNode(int key,int level)
    {
        Node* new_node = new Node(key, level);
        return new_node;
    }

    //generates random level including probability
    int randomLevel()
    {
        int level = 0;
        int r = rand() % 100;
        while ((r < PROB * 100) && (level < MAX_LEVEL))
        {
            level++;
            r = rand() % 100;
        }
        return level;
    }

    //inserts one element to the list
    void insertElement(int key)
    {
        Node* current = HEADER;
        Node** update=new Node*[MAX_LEVEL+1];
        for (int i = 0; i <MAX_LEVEL+1; i++)
        {
            update[i] = NULL;
        }
        for (int i = level; i >= 0; i--)
        {
            while ((current->forward[i] != NULL) && (current->forward[i]->key < key))
            {
                current = current->forward[i];
            }
                update[i] = current;

        }
        current = current->forward[0];
        if (current == NULL || current->key != key)
        {
            int r_level = randomLevel();
            if (r_level > level)
            {
                for (int i = level + 1; i < r_level + 1; i++)
                {
                    update[i] = HEADER;
                }
                level = r_level;
            }
            Node* new_node = createNode(key, r_level);
            for (int i = 0; i < r_level+1; i++)
            {
                new_node->forward[i] = update[i]->forward[i];
                update[i]->forward[i] = new_node;
            }
            cout << "Yikes" << endl;
        }

    }
    void showAll()
    {
        Node* current = HEADER->forward[0];
        while (current != NULL)
        {
            cout << endl << "Key value:" << current->key<<endl;
            current = current->forward[0];
        }
    }

    //inserts many elements to the list
    void insertManyElements()
    {}

    //finds element in a list
    void findElement()
    {}

    //returns an array of how many nodes there are in particular levels
    int howManyNodes()
    {}

    //shows X first elements
    void showFirstElements()
    {}

    //shows Y last elements
    void showLastElements()
    {}

    //deletes an element from a list
    void deleteElement()
    {}

    //deletes entire list
    void deleteList()
    {}

};
int main()
{
    srand(time(NULL));
    Skiplist my_list(5, 0.5);
    my_list.insertElement(6);
    my_list.insertElement(11);
    my_list.insertElement(4);
    my_list.insertElement(1);
    my_list.insertElement(2);
    my_list.insertElement(20);
    my_list.showAll();


    return 0;
}