#!/usr/bin/env python
#-*- coding:utf-8 -*-
#
"""
Demonstrate number of hands needed to pick Ace of Spades
from a shuffled pack of cards. The best case is 1, the worst
is infinity. Lets see....
"""

try:
    import sys
    from random import Random
    r = Random()
except Exception,rand_load:
    print "Some error occured in random init\n%s" % (
        rand_load)
    sys.exit()

def shuffle_pack():
    """
    Generate an unmixed deck and shuffle it.
    """
    cards = ['spades_ace', 'spades_two', 'spades_three', 'spades_four', 'spades_five', 'spades_six', 'spades_seven', 'spades_eight', 'spades_nine', 'spades_ten', 'spades_jack', 'spades_queen', 'spades_king', 'hearts_ace', 'hearts_two', 'hearts_three', 'hearts_four', 'hearts_five', 'hearts_six', 'hearts_seven', 'hearts_eight', 'hearts_nine', 'hearts_ten', 'hearts_jack', 'hearts_queen', 'hearts_king', 'clubs_ace', 'clubs_two', 'clubs_three', 'clubs_four', 'clubs_five', 'clubs_six', 'clubs_seven', 'clubs_eight', 'clubs_nine', 'clubs_ten', 'clubs_jack', 'clubs_queen', 'clubs_king', 'diamonds_ace', 'diamonds_two', 'diamonds_three', 'diamonds_four', 'diamonds_five', 'diamonds_six', 'diamonds_seven', 'diamonds_eight', 'diamonds_nine', 'diamonds_ten', 'diamonds_jack', 'diamonds_queen', 'diamonds_king']
    shuffled = []
    while not len( shuffled ) == 52:
        shuffled.append( cards.pop( r.randint( 0, len( cards ) - 1 ) ) )
    return shuffled

def pick_card( pack ):
    """
    Keep picking cards from random positions
    until you hit the Ace of Spades.
    Return the hands needed
    """
    count, result = 0, 0
    while result == 0:
        if pack[ r.randint( 0, 51 ) ] == 'spades_ace':
            return count
        else:
            count += 1

if __name__ == '__main__':
    average, lowest, highest = 0, 999999, 0
    for i in range( 1000 ):
        iterations = pick_card( shuffle_pack() )
        average += iterations
        if iterations < lowest:
            lowest = iterations
        if iterations > highest:
            highest = iterations

    print "Iterations: 1000\nHighest: %s\nLowest: %s\nAverage: %s" % (
        highest + 1, lowest + 1, average / 1000 )