如何实现青少年将数字转换为单词的逻辑

# 数字到单词的映射表
number_to_word = {
    1: "one",
    2: "two",
    3: "three",
    4: "four",
    5: "five",
    6: "six",
    7: "seven",
    8: "eight",
    9: "nine"
}

# 特殊情况的映射表
special_cases = {
    10: "ten",
    11: "eleven",
    12: "twelve",
    13: "thirteen",
    14: "fourteen",
    15: "fifteen",
    16: "sixteen",
    17: "seventeen",
    18: "eighteen",
    19: "nineteen"
}

def convert_number_to_word(number):
    # 输入验证
    if not isinstance(number, int) or number < 1 or number > 19:
        return "Invalid input"

    # 特殊情况处理
    if number in special_cases:
        return special_cases[number]

    # 数字转换为单词
    return number_to_word[number]

# 测试用例
print(convert_number_to_word(5))  # 输出: five
print(convert_number_to_word(13))  # 输出: thirteen
print(convert_number_to_word(20))  # 输出: Invalid input