题解 | 24点游戏算法

def choose2(nums: list[float]):
    n = len(nums)
    d = set(range(n))
    for i in range(n):
        for j in range(i + 1, n):
            yield nums[i], nums[j], [nums[k] for k in d.difference([i, j])]


def calcs(a: float, b: float):
    yield a + b
    yield a - b
    yield b - a
    yield a * b
    if b != 0:
        yield a / b
    if a != 0:
        yield b / a


def solve(nums: list[float]):
    if len(nums) == 1 and abs(nums[0] - 24) < 1e-6:
        return True
    for a, b, c in choose2(nums):
        for x in calcs(a, b):
            # if abs(x - 24) < 1e-6:
            #     print(a, b, x, c)
            if solve([x] + c):
                return True
    return False


print("true" if solve(list(map(int, input().split()))) else "false")