Algorithms For Dummies

 Challenging Difficult Problems

card, which amounts to 1 after picking all the cards: (1/52) * 52 = 1. Instead, you 

can change this simple random algorithm by discarding the cards that you’ve seen 

from your possible choices:

from random import choice

my_cards = deck.copy()

guessed = 0

for card in deck:

    if card == choice(my_cards):

        guessed 

+= 1

    else:

        my_cards.pop(my_cards.index(card))

print ('Guessed %i card(s)' % guessed)

Guessed 1 card(s)

Now, on average, you’ll guess the right card more often because as the deck 

decreases, your chances of guessing increases and you’ll likely guess correctly 

more often when nearing the end of the game. (Your chances are 1 divided by the 

number of cards left in the deck).

Counting cards can provide an advantage in card games. A team of MIT students 

used card counting and probability estimates to win huge amounts in Las Vegas 

until the practice was banned from Casinos. The story even inspired a 2008 film 

entitled 21, starring Kevin Spacey. You can read more about the story at: 

http:// 

www.bbc.com/news/magazine-27519748.