from random import choice

def flipCoin() -> str:
    return choice("HT")

def estimateProbability(trials: int) -> float:
    heads = 0
    for _ in range(trials):
        tosses: list[str] = []
        for _ in range(5):
            tosses.append(flipCoin())
        if len([h for h in tosses if h == "H"]) == 2:
            heads += 1
    else:
        return heads / trials


def testTwoHeadsInFiveFlipsProblem():
    print('Testing the twoHeadsInFiveFlips Problem...', end='')
    trials = 10**5
    p = estimateProbability(trials)
    print(p)
    assert(0.30 <= p <= 0.32) # actual answer is about 0.313
    print('Passed!')

def main():
    testTwoHeadsInFiveFlipsProblem()

main()