gistfile1.py

""" 
MIT License
----------------------------------------------------------------
Copyright (c) 2009 David Lyon

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
-----------------------------------------------------------------
About:
Simulates a drunk person walking on a pier up to a given limit for sizes.  Prints out the size then the average time it took for the drunk to fall off of the pier.  For more trials, change the 'trials' variable in drunkGuy.  Defaults to 1000 trials.  More is better, but takes MUCH longer.
"""

import random

def theTap(size):
    """ theTap is a generator that returns points.  It stops when x or y exceed the size, or hit -1."""
    loc = [int(size/2), int(size/2)] #where my drunk at? holds an 'x,y' pair
    while( -1 < loc[0] < size and -1 < loc[1] < size):
        loc = [x + random.randint(-1,1) for x in loc]
        yield loc
    

def drunkGuy(piersize=20):
    """ Takes a max pier size and tests 1 up to piersize to see how long on average a drunk guy will stay on the pier"""
    trials = 1000
    for x in range(1, piersize+1):
        time = 0 #holds the number of iterations, or 'time'
        for y in range(0, trials):
            points = [] # a list of points we've been to, a list of lists of points [x,y]
            [points.append(p) for p in theTap(x)] #keep going back to the tap until you fall off the pier
            time = time + len(points)
        print("%02d" % (x), "   ", "AVG", "   ",time/trials) 

drunkGuy(50)