Выделение памяти

// ConsoleApplication62.cpp : Defines the entry point for the console application.
//
 
#include "stdafx.h"
#include "stdlib.h"
#include "iostream"
#include <ctime>
 
struct Item
{
public: 
    int theProperty; 
    Item* tail;
};
 
void _tmain()
{
    Item* i = nullptr;
    std::cout << sizeof(Item) << "\n";
    Item* list = (Item*)malloc(sizeof(Item));
    list->theProperty = -1;
    list->tail = NULL;
    unsigned start = clock();
    for (int i = 0; i < 100000000; i++)
    {
        Item* temp = (Item*)malloc(sizeof(Item));
        temp->theProperty = rand();
        temp->tail = list;
        list = temp;
    }
 
    std::cout << clock()-start << "\n";
    Item* p = list;
    float result = 0;
    start = clock();
 
    while (p->tail != NULL)
    {
        result += p->theProperty;
        p = p->tail;
    }
 
    std::cout << clock()-start << "\n";
    p = list;
    start = clock();
    while (p->tail != NULL)
    {
        Item* temp = p->tail;
        free(p);
        p = temp;
    }
    std::cout << clock()-start << "\n";
}