Stackoverflow Program

#include <iostream>
#include <fstream>
#include <ctime>
#include <cstdlib>

using namespace std;

class node
{
    public:
    int key;
    double d_variable;
    char ch_variable;
    node* next;
};
class my_list
{
    public:
    node * head;
    int size;

    my_list()
    {
        head = NULL;
        size = 0;
    }
    void AddOneElement(int value)   //adding one element with value provided by user
    {
        node* temp1,* temp2;
        node** temp3;
        temp3 = &head;
        temp1 = new node;
        temp1->key = value;
        temp1->d_variable = rand();
        temp1->ch_variable = 'T';
        temp2 = head;
        while (temp2 != NULL && temp2->key <= temp1->key)
        {
            if (temp2->key == temp1->key)
                return;
            temp3 = &temp2->next;
            temp2 = temp2->next;
        }
            *temp3 = temp1;
            temp1->next = temp2;
            size++;
    }
    void AddManyElements(int amount)    //adding many elements with random key value
    {
        for (int i = 0; i < amount; i++)
        {
        node* temp1,* temp2;
        node** temp3;
        temp3 = &head;
        temp1 = new node;
        temp1->key = ( 4  *rand()) % 99901 + 99;
        temp1->d_variable = rand();
        temp1->ch_variable = 'T';
        temp2 = head;
        while (temp2 != NULL && temp2->key <= temp1->key)
            {
                if (temp2->key == temp1->key)
                    {
                    temp1->key = (4 * rand()) % 99901 + 99;
                    temp2 = head;
                    }
                else
                    {
                    temp3 = &temp2->next;
                    temp2 = temp2->next;
                    }
            }
                *temp3 = temp1;
                temp1->next = temp2;
                size++;
        }
    }
    /*void ShowElements()               //function that shows all elements, thats for me for testing purposes
    {
        node* temp;
        temp = head;
        int i = 0;
        if(temp!=NULL)
        {
            while (temp!=NULL)
            {
                cout << "Key number "<<i+1<<" :" << temp->key << endl;
                temp = temp->next;
                i++;
            }
        }
        else    //case in which list is empty
        {
            cout << endl << "This list is empty!" << endl;
        }

    }*/
    void ListSize()
    {
        cout << endl << "Size:" << size<<endl;
    }
    void DeleteElement(int value)
    {
        node *temp1, *temp2,*temp3;
        temp1 = new node;
        temp3 = new node;
        temp1->key = value;
        temp2 = head;
        if (temp2 == NULL)      //list is empty
        {
            cout << "There is no list" << endl;
            return;
        }
        if (temp2 != NULL && temp2->key == temp1->key)  //element is on the first place
        {
            temp3 = temp2->next;
            delete temp2;
            head = temp3;
            size--;
            return;
        }
        while (temp2 != NULL && temp2->key != temp1->key)   //searching for the element through list
        {
            temp3 = temp2;
            temp2 = temp2->next;
        }
        if (temp2 == NULL)return;   //there is no element
        temp3->next = temp2->next;  //element has been found
        delete temp2;
        size--;
    }
    void DeleteList()
    {
        node* temp1;
        temp1 = head;
        if (temp1 == NULL)return;
        else
        {
            while (temp1 != NULL)
            {
                node* temp2;
                temp2 = temp1;
                temp1 = temp1->next;
                delete temp2;
                size--;
            }
            head = temp1;
        }
    }
    void ShowFirstElements(int value)
    {
        if (value > size)return;
        else
        {
            node* temp;
            temp = head;
            if (temp == NULL)return;
            else
            {
                for (int i = 0; i < value; i++)
                {
                    cout << "Key:" << temp->key << endl;
                    temp = temp->next;
                }
            }

        }
    }
    void ShowLastElements(int value)
    {
        node* temp;
        temp = head;
        if (head == NULL)return;
        if (value > size)return;
        int j = size - value;
        for (int i = 0; i <j; i++)
        {
            temp = temp->next;
        }
        while (temp != NULL)
        {
            cout << endl << "Key:" << temp->key;
            temp = temp->next;
        }
    }
    void FindKey(int value)
    {
        node* temp;
        temp = head;
        if (temp == NULL)
        {
            cout << endl << "List is empty" << endl;
        }
        else
        {
            while (temp != NULL && temp->key != value)
            {
                temp = temp->next;
            }
            if (temp == NULL)
            {
                cout << endl << "Element does not exist" << endl;
            }
            else
            {
                cout << endl << "Element does exist";
                cout<< endl << "key:" << temp->key;
                cout << endl << "d_variable:" << temp->d_variable;
                cout << endl << "ch_variable:" << temp->ch_variable;
            }
        }

    }
};

int main()
{
    clock_t begin, end;
    double time_spent;
    begin = clock();
    ifstream my_file;
    int amount=0, key1=0, key2=0, key3=0, key4=0, key5=0;
    my_list testing;
    srand(time(NULL));


    my_file.open("inlab02.txt");

    if (my_file.good())
    {
        cout << "File opened succesfully, loading variables..." << endl;
        my_file >> amount;
        my_file >> key1;
        my_file >> key2;
        my_file >> key3;
        my_file >> key4;
        my_file >> key5;
    }
    else
    {
        cout << endl << "Could not open the file, ending program..." << endl;
    }
    testing.FindKey(key1);
    testing.AddManyElements(amount);
    testing.ListSize();
    testing.ShowFirstElements(20);
    cout << endl;
    testing.AddOneElement(key2);
    cout << endl;
    testing.ShowFirstElements(20);
    testing.AddOneElement(key3);
    cout << endl;
    testing.ShowFirstElements(20);
    testing.AddOneElement(key4);
    cout << endl;
    testing.ShowFirstElements(20);
    testing.AddOneElement(key5);
    testing.DeleteElement(key3);
    cout << endl;
    testing.ShowFirstElements(20);
    testing.DeleteElement(key2);
    cout << endl;
    testing.ShowFirstElements(20);
    testing.DeleteElement(key5);
    testing.ListSize();
    testing.FindKey(key5);
    cout << endl;
    testing.ShowLastElements(11);
    testing.DeleteList();
    testing.ShowLastElements(11);
    testing.ListSize();
    my_file.close();
    end = clock();
    time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
    cout << endl << "Execution time:" << time_spent;
    return 0;
}