Frog Riddle

frog_riddle.py

#!/usr/bin/env python
import random
# Frog 0 for female, 1 for male

def create_frog():
    return random.randint(0, 1)

def has_croak(pairs):  # also male
    return 1 in pairs

def has_female(frogs):
    return 0 in frogs

def choose_without_croak(choose_two):
    frogs = [create_frog() for i in range(3)]
    # first frog at the right side
    # second and third at the left side

    if choose_two:
        return has_female(frogs[1:])  # choose two frogs

    return has_female(frogs[0:1])

def main():
    total = 10000
    correct = 0
    for i in range(total):
        correct += choose_without_croak(True)
    print('Just choose two frogs. Total: {}, correct: {}. P = {}'.format(total, correct, correct / total))

    correct = 0
    for i in range(total):
        correct += choose_without_croak(False)
    print('Just choose one frog. Total: {}, correct: {}. P = {}'.format(total, correct, correct / total))

# The exact question is,
# "What is the probability of the frogs in the pair has female,
# given that one of them is male?"
def exact_calculation():
    total = 10000
    croak = 0
    correct = 0
    for i in range(total):
        frogs = [create_frog() for i in range(3)]
        if has_croak(frogs[1:]):
            croak += 1
            if has_female(frogs[1:]):
                correct += 1
    print('Total croak: {}, correct: {}. P = {}'.format(croak, correct, correct / croak))

main()
exact_calculation()