try to generate multiple arrays with random numbers but get the same array every time

I was trying to make a simulation of randomly picking number from 1-36, and to see how many time do I need to pick all the different 36 number. If I picked total of 10 duplicated number I can pick a number that has not been picked, and recount duplication. Anyway, my code works fine if I only create one array contains random numbers. But I add a for loop outside of the whole process and repeat it 100 times in order to find out on average how many time do I need. And the code create 100 of same arrays.

    #include "iostream"
    #include "stdlib.h"
    #include "time.h"

    using namespace std;

    class Lottery
    {
    private:
        int PickNonExistingNum()//pick a number that's not in num
        {   
            int pick;   
            pick = RandomNumber();
            for (int m = 0; m < 36; m++)
            {
                if (pick == num[m])
                {
                    pick = RandomNumber();
                    m = 0;
                    continue;
                }
            }
            return pick;
        }

    public:
        int check;
        int TimeOfPicking = 0;      //how many time we pick a number
        int num[36] = { 0 };        //array contains all the number
        bool same = false;          //flag that indicates consistency
        int accum = 0;              //how many time we pick a same number, when reach 10 we pick again
        bool IsRandomSeeded = false;

        int i = 0;                  //used to change i value in for loop of main loop

        int RandomNumber()//generate a number from 1 to 36
        {
            int number;
            number = rand() % 36 + 1;
            return number;
        }

        bool CheckExistingNum()
        {
            for (int k = 0; k < 36; k++)
            {
                if (check == num[k])
                {
                    if (accum < 10)//add 1 to accum each time when there's a same number
                    {
                        i--;
                        accum++;
                        same = true;
                        break;
                    }
                    else if (accum == 10)//pick again when accum reach 10
                    {
                        num[i] = DoubleCheckPick(PickNonExistingNum());
                        accum = 0;
                        same = true;
                        break;
                    }
                }
            }
            return same;
        }

        void Picking()
        {
            for (i; i < 36; i++)//finish the loop when player had picked all 36 numbers
            {
                check = RandomNumber();//give check a random value between 1 and 36
                TimeOfPicking++;    //add 1 time to the total time of picking
                same = false;       //set flag to false

                if (!CheckExistingNum())//give checked value to num if there's no same number
                {
                    num[i] = check;
                }
            }

            cout << "Pick " << TimeOfPicking << " time" << endl;//show results
            cout << "the numbers are:" << endl;
            for (int m = 0; m < 36; m++)
            {
                cout << num[m] << ", ";
            }
            cout << endl;
        }

        bool DoubleCheck()
        {
            for (int m = 0; m < 36; m++)
            {
                for (int k = m + 1; k < 36; k++)
                {
                    if (num[m] == num[k])
                    {
                        cout << "there's a same number: " << num[m] << endl << endl;
                        return false;
                    }
                }
            }
            cout << "no same number" << endl << endl;
            return true;
        }

        int DoubleCheckPick(int check)
        {
            for (int m = 0; m < 36; m++)
            {
                if (check == num[m])
                {
                    check = PickNonExistingNum();
                    m = 0;
                    continue;
                }
            }
            return check;
        }

        void reset()//reset all the value for multiple process
        {
            int TimeOfPicking = 0;      //how many time we pick a number
            int num[36] = { 0 };        //array contains all the number
            int same = false;           //flag that indicates consistency
            int accum = 0;              //how many time we pick a same number, when reach 10 we pick again
            int check = 0;

            int i = 0;                  //used to change i value in for loop of main loop
        }

    };


    int main()
    {   
        Lottery Num;

        //int t = 0;

        srand(time(NULL));              //set random generator

        int PickingTime[100] = { 0 };//an array contains all 100 times of data
        double sum = 0;              //the sum of all the data

        for (int i = 0; i < 100; i++)//run the program 100 times
        {
            cout << "the " << i + 1 << " process" << endl;

            int wait = clock();
            while (clock() <= (wait + 1000));//delay for 3000 unit time 

            Num.reset();
            Num.Picking();
            if (!Num.DoubleCheck())//if there's a same number
            {
                cout << "fail process" << endl;
                i--;            //redo the process
                continue;
            }
            else
            {
                PickingTime[i] = Num.TimeOfPicking;
            }
        }

        for (int i = 0; i < 100; i++)
        {
            sum += PickingTime[i];
        }

        cout << "the average picking time in 100 test is: " << sum / 100 << endl;

        return 0;
    }

and the result looks like this result all the arrays are the same. I guess it might be the rand() problem, but I can't find any solution that will work.