rolls.py

import math
import multiprocessing
import random

# Rolls 231 d4 and returns the total number of 1s
def roll():
    ones = 0
    for i in range(231):
        # Returns a 2 bit random binary number (00, 01, 10, 11) => 1, 2, 3, 4
        if random.getrandbits(2) == 0:
            ones += 1
    return ones


# Attempt *count* roll sessions and return the highest result
def attempt(count):
    maxOnes = 0
    for i in range(count):
        r = roll()
        if r > maxOnes:
            maxOnes = r
    return maxOnes


# Entry point of the program
def main():
    # 1 Billion
    goal = 1000000000

    # This number should be the number of cores on the machine
    # Most laptops have between 4 and 16
    cores_on_machine = 48

    # Set up parallel tasks. Put one task on each core
    pool = multiprocessing.Pool(processes=cores_on_machine)

    # Determine how much work per core, try to split evenly
    per_core = int(goal / cores_on_machine)

    # Goal might not be divisble by the number of core. Grab the missing count here
    extra_missing = goal - (per_core * cores_on_machine)

    # Assign the work to each core
    inputs = [per_core] * cores_on_machine
    inputs[0] = inputs[0] + extra_missing

    # Do the work
    outputs = pool.map(attempt, inputs)

    # Grab the max result from among all the cores
    maxOnes = max(outputs)

    # Print out the summary
    print("Highest Ones Roll:", maxOnes)
    print("Number of Roll Sessions: ", sum(inputs))


if __name__ == "__main__":
    main()