Card* CardShuffler<Card>::PopRandom(Card** head, int size) {
//choose a card to return
int i = rand() % size;
//returning the top card
if (i == 0) {
Card* ret = *head;
(*head) = (*head)->GetNext();
return ret;
}
//find the prev of the card to return
Card* prev = *head;
while(--i) prev = prev->GetNext();
//pop this card
Card* ret = prev->GetNext();
prev->SetNext(ret->GetNext());
ret->SetNext(nullptr);
return ret;
}
void CardShuffler<Card>::operator()(Card** head) {
//count the number of cards
int size = 0;
Card* it = *head;
while (it) it = it->GetNext(), size++;
//shuffle the cards
Card* tmpHead = nullptr;
while(size) {
PushFront(&tmpHead, PopRandom(head, size));
size--;
}
*head = tmpHead;
}
