#Programming for the Puzzled -- Srini Devadas #You Can Read Minds (With a Little Calibration) #Five random cards are chosen and one of them is hidden. #Given four cards in a particular order, you can figure out what the fifth card is! #Deck is are a list of strings, each string is a card #The order of cards in the list matters. deck = ['A_C', 'A_D', 'A_H', 'A_S', '2_C', '2_D', '2_H', '2_S', '3_C', '3_D', '3_H', '3_S', '4_C', '4_D', '4_H', '4_S', '5_C', '5_D', '5_H', '5_S', '6_C', '6_D', '6_H', '6_S', '7_C', '7_D', '7_H', '7_S', '8_C', '8_D', '8_H', '8_S', '9_C', '9_D', '9_H', '9_S', '10_C', '10_D', '10_H', '10_S', 'J_C', 'J_D', 'J_H', 'J_S', 'Q_C', 'Q_D', 'Q_H', 'Q_S', 'K_C', 'K_D', 'K_H', 'K_S'] #Given 5 cards, Assistant hides an appropriate card #He/she reads out the remaining four cards after choosing their order carefully! def AssistantOrdersCards(): print ('Cards are character strings as shown below.') print ('Ordering is:', deck) #Initialization cards, cind, cardsuits, cnumbers = [], [], [], [] numsuits = [0, 0, 0, 0] #Take cards as input from user/audience #Various data structures are filled in for i in range(5): print ('Please give card', i+1, end = ' ') card = input('in above format:') cards.append(card) n = deck.index(card) cind.append(n) cardsuits.append(n % 4) cnumbers.append(n // 4) numsuits[n % 4] += 1 if numsuits[n % 4] > 1: pairsuit = n % 4 #Find two cards out of the 5 that have the same suit. Guaranteed to exist. cardh = [] for i in range(5): if cardsuits[i] == pairsuit: cardh.append(i) #Figure out which card needs to be hidden and what number to encode hidden, other, encode = outputFirstCard(cnumbers, cardh, cards) remindices = [] for i in range(5): if i != hidden and i != other: remindices.append(cind[i]) #Order the three cards in ascending order sortList(remindices) #Given the number that needs to be encoded, order the cards appropriately outputNext3Cards(encode, remindices) return #This procedure figures out which card should be hidden based on the distance #between the two cards that have the same suit. #It returns the hidden card, the first exposed card, and the distance def outputFirstCard(numbers, oneTwo, cards): encode = (numbers[oneTwo[0]] - numbers[oneTwo[1]]) % 13 if encode > 0 and encode <= 6: hidden = oneTwo[0] other = oneTwo[1] else: hidden = oneTwo[1] other = oneTwo[0] encode = (numbers[oneTwo[1]] - numbers[oneTwo[0]]) % 13 ## #The following print statement is just for debugging! ## print ('Hidden card is:', cards[hidden], 'and need to encode', encode) print ('First card is:', cards[other]) return hidden, other, encode #This procedure orders three cards depending on the number "code" that #needs to be encoded. def outputNext3Cards(code, ind): if code == 1: second, third, fourth = ind[0], ind[1], ind[2] elif code == 2: second, third, fourth = ind[0], ind[2], ind[1] elif code == 3: second, third, fourth = ind[1], ind[0], ind[2] elif code == 4: second, third, fourth = ind[1], ind[2], ind[0] elif code == 5: second, third, fourth = ind[2], ind[0], ind[1] else: second, third, fourth = ind[2], ind[1], ind[0] print ('Second card is:', deck[second]) print ('Third card is:', deck[third]) print ('Fourth card is:', deck[fourth]) #Sorts elements in tlist in ascending order. def sortList(tlist): for index in range(0, len(tlist)-1): ismall = index for i in range(index, len(tlist)): if tlist[ismall] > tlist[i]: ismall = i tlist[index], tlist[ismall] = tlist[ismall], tlist[index] return #This procedure takes four cards encoded properly and determines the hidden card. def MagicianGuessesCard(): print ('Cards are character strings as shown below.') print ('Ordering is:', deck) cards, cind = [], [] for i in range(4): print ('Please give card', i+1, end = ' ') card = input('in above format:') cards.append(card) n = deck.index(card) cind.append(n) if i == 0: suit = n % 4 number = n // 4 #Use the ordering of the last 3 cards to determine distance from 1st card if cind[1] < cind[2] and cind[1] < cind[3]: if cind[2] < cind[3]: encode = 1 else: encode = 2 elif ((cind[1] < cind[2] and cind[1] > cind[3]) or (cind[1] > cind[2] and cind[1] < cind[3])): if cind[2] < cind[3]: encode = 3 else: encode = 4 elif cind[1] > cind[2] and cind[1] > cind[3]: if cind[2] < cind[3]: encode = 5 else: encode = 6 #Knowing the number and the suit gives the card index and then string hiddennumber = (number + encode) % 13 index = hiddennumber * 4 + suit print ('Hidden card is:', deck[index]) #This procedure is similar to AssistantOrdersCards() except it #takes in a large number and "randomly" generates five cards. def ComputerAssistant(): print ('Cards are character strings as shown below.') print ('Ordering is:', deck) cards, cind, cardsuits, cnumbers = [], [], [], [] numsuits = [0, 0, 0, 0] number = 0 while number < 99999: number = int(input('Please give random number' + ' of at least 6 digits:')) for i in range(5): number = number * (i + 1) // (i + 2) n = number % 52 cards.append(deck[n]) cind.append(n) cardsuits.append(n % 4) cnumbers.append(n // 4) numsuits[n % 4] += 1 if numsuits[n % 4] > 1: pairsuit = n % 4 ## #Just for debugging ## print (cards) cardh = [] for i in range(5): if cardsuits[i] == pairsuit: cardh.append(i) hidden, other, encode = outputFirstCard(cnumbers, cardh, cards) remindices = [] for i in range(5): if i != hidden and i != other: remindices.append(cind[i]) sortList(remindices) outputNext3Cards(encode, remindices) guess = input('What is the hidden card?') if guess == cards[hidden]: print ('You are a Mind Reader Extraordinaire!') else: print ('Sorry, not impressed!') return