3x+1 demo

#include <iostream>
//#include <vector>
#include <Windows.h>


using namespace std;

class list {
public:
    unsigned long long size;
    bool* masterlist;
    list() {
        masterlist = new bool[1];
        size = 1;
    }
    list(unsigned long long ull) {
        masterlist = new bool[ull];
        size = ull;
    }
    ~list() {
        if (masterlist) {
            delete masterlist;
        }
    }

    void Realloc(unsigned long long ull) {
        bool* m = new bool[ull];
        ZeroMemory(m, ull);
        //good place for a size check
        memcpy(m, masterlist, size);
        delete masterlist;
        masterlist = m;
        size = ull;
    }

    bool& operator[](unsigned long long ull) {
        if (ull > size - 1) { Realloc(ull + 1); }
        return masterlist[ull];
    }
    void print() {
        for (unsigned long long ull = 0; ull < size; ull++) {
            if(masterlist[ull])
                cout << ull << '\n';
        }
    }
};

class node {
public:
    node* prev;
    node* next;
    int num;

    node() :prev{ nullptr }, next{ nullptr }, num{ 0 }{}
    node(int num=0,node* prev = nullptr, node* next = nullptr) :prev{ prev }, next{ next }, num{ num }{}
    node(node* prev) : num{ 0 }, prev{ prev }, next{ nullptr }{}

    node* Next() { return next; }
    node* Prev() { return prev; }


};

unsigned long long xPlusOne(unsigned long long ull) {
    if (ull & 1) { return (ull * 3) + 1; } //0dd
    return ull >> 1; //bitwise operations... beastmode unlocked
}

int main() {

    unsigned long long in = 3;
    list l;
    do {
        in = xPlusOne(in);
        l[in] = true;
    } while (in != 1);
    l.print();
}