C#

List<uint> deck = new List<uint>();
uint[] cards = new uint[52];

Random rnd = new Random();
DateTime st = DateTime.Now;
for (int i = 0; i < 1000000; i++)
{
    deck.Clear();
    deck.AddRange(cards);

    //remove 5 cards
    deck.RemoveAt(rnd.Next(0, deck.Count - 1));
    deck.RemoveAt(rnd.Next(0, deck.Count - 1));
    deck.RemoveAt(rnd.Next(0, deck.Count - 1));
    deck.RemoveAt(rnd.Next(0, deck.Count - 1));
    deck.RemoveAt(rnd.Next(0, deck.Count - 1));
}
DateTime ed = DateTime.Now;</uint></uint>

public class Deck {

	private int[] _cards;
	private int _used;
	private Random _rnd;

	public Deck() {
		_cards = new int[52];
		_used = 0;
		_rnd = new Random();
	}

	public void Init() {
		for (int i = 0; i < 52; i++) {
			_cards[i] = i;
		}
		_used = 52;
	}

	public void GetHand(int[] hand) {
		for (int i=0;i<5;i++) {
			int index = _rnd.Next(_used);
			hand[i] = _cards[index];
			_used--;
			_cards[index] = _cards[_used];
		}
	}

}

Deck deck = new Deck();
int[] hand = new int[5];
for (int i = 0; i < 1000000; i++) {
	deck.Init();
	deck.GetHand(hand);
}

Luc Pattyn wrote:

If on the other hand, you decide to stick with the collection, there is no real need to build it over and over; once done, you can add the chosen items back to the collection.