Skip to content

Instantly share code, notes, and snippets.

@ShiangYong

ShiangYong/main.py

Last active Dec 4, 2016
Embed
What would you like to do?
Python code to solve the Lonesome King problem, http://fivethirtyeight.com/features/the-puzzle-of-the-lonesome-king/
import statistics
import random
import numpy as np
import time
def repeated_cull_sim(initial_size, runs):
sum = 0
init_time = time.time()
for j in range(runs):
sum += repeated_cull(initial_size)
print("N=", initial_size, " runs =", runs, " num_lonely=", runs-sum, " prob_lonely=", (runs-sum)/runs,
' run time (hr) = {0:.3f}'.format((time.time() - init_time)/3600.0))
def repeated_cull(initial_size):
size = int(initial_size)
prob = [1.0, 0.0, 1.0, 0.25, 0.4074074074074074, 0.53125, 0.5838577777777778, 0.5611357992938068, 0.5109616766040821]
while size >= len(prob):
size = cull(size)
return np.random.random() > prob[size]
def cull(start_num):
subjects = np.ones(start_num, dtype=np.int)
rand = np.random.randint(0, start_num-1, start_num)
for i in range(start_num):
if rand[i] >= i:
rand[i] += 1
subjects[rand] = 0
return np.sum(subjects)
# main program
# first parameter is initial population size and the second is the number of simulations to run
repeated_cull_sim(56000, 1000*1000)
@ShiangYong

This comment has been minimized.

Copy link
Owner Author

@ShiangYong ShiangYong commented Dec 4, 2016

Running a million simulations with N = 56000 took about 10 hours on my machine.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment