memory handling (vectors)

mm.cpp

#include <iostream>

int main ()
{
    int sz = 0, unalloc_space = 1;
    int *elem, input = 0, *alloc_mem = nullptr, *temp_mem;

    while (std::cin >> input) {

        if (alloc_mem == nullptr) {
        ++unalloc_space;
        unalloc_space *= unalloc_space;
        alloc_mem = new int [unalloc_space];
        std::cout << "unalloc space " << unalloc_space << std::endl;
        }

        if (sz == unalloc_space) {

                std::cout << "allocating resources " << sz  << std::endl;
            unalloc_space *= unalloc_space;
            temp_mem = new int [unalloc_space];

            for (int i = 0; i != sz; ++i)
                *(temp_mem + i) = *(alloc_mem + i);

            delete alloc_mem;

            alloc_mem = new int [unalloc_space];

            for (int i = 0; i != sz; ++i)
                *(alloc_mem + i) = *(temp_mem + i);

            delete temp_mem;
        }


        *(alloc_mem + sz) = input;
          ++sz;
    }

    for (int i = 0; i != sz; ++i)
        std::cout << *(alloc_mem + i) << std::endl;

    delete alloc_mem;

    return 0;
}