十进制数字转换为二进制

a = int(input('请输入要转换的数：'))


def _(a: int):
    b = ''
    while a >= 1:
        if a == 1 or a % 2:
            b += "1"
        else:
            b += "0"
        a = a // 2
    return b[::-1]


print(_(a))