// PRE: len is the length of the memory block that starts at array
void test1(int* array, int len){
    int* fourth = array + 3;
    if (len > 3){
        std::cout << *fourth << std::endl;
    }

    for (int* p = array; p != array + len; ++p){
        std::cout << *p << std::endl;
    }
}