Description
Convert a non-negative integer to its english words representation. Given input is guaranteed to be less than 231 - 1.
Example 1:
Input: 123
Output: "One Hundred Twenty Three"
Example 2:
Input: 12345
Output: "Twelve Thousand Three Hundred Forty Five"
Example 3:
Input: 1234567
Output: "One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven"
Example 4:
Input: 1234567891
Output: "One Billion Two Hundred Thirty Four Million Five Hundred Sixty Seven Thousand Eight Hundred Ninety One"
描述
将非负整数转换为其对应的英文表示。可以保证给定输入小于 231 - 1 。
示例 1:
输入: 123
输出: "One Hundred Twenty Three"
示例 2:
输入: 12345
输出: "Twelve Thousand Three Hundred Forty Five"
示例 3:
输入: 1234567
输出: "One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven"
示例 4:
输入: 1234567891
输出: "One Billion Two Hundred Thirty Four Million Five Hundred Sixty Seven Thousand Eight Hundred Ninety One"
思路
- 数字三个为一节，我们每三个数字做一个分段，对其用用英文表达出来，在加上对应节所在的单位即可.
# -*- coding: utf-8 -*- # @Author: 何睿 # @Create Date: 2019-02-04 19:25:43 # @Last Modified by: 何睿 # @Last Modified time: 2019-02-04 20:31:32 class Solution: def numberToWords(self, num): """ :type num: int :rtype: str """ # 维护一个数字到英语的转换字典 self.IntEng = { "0": 'Zero', "1": 'One', "2": 'Two', "3": 'Three', "4": 'Four', "5": 'Five', "6": 'Six', "7": 'Seven', "8": 'Eight', "9": 'Nine', "10": 'Ten', "11": 'Eleven', "12": 'Twelve', "13": 'Thirteen', "14": 'Fourteen', "15": 'Fifteen', "16": 'Sixteen', "17": 'Seventeen', "18": 'Eighteen', "19": 'Nineteen', "20": 'Twenty', "30": 'Thirty', "40": 'Forty', "50": 'Fifty', "60": 'Sixty', "70": 'Seventy', "80": 'Eighty', "90": 'Ninety', "100": 'Hundred', } # 没三节为一个单位，2^31最大用到的单位为Billion units = ['', 'Thousand', 'Million', 'Billion'] res = '' # 将数字转换成为字符串 _str = str(num) # count:字符串中字符个数，i:数字三个为一节，当前数字所在节 count, i = len(_str), 0 while count - (i + 1) * 3 >= 0: # 取出三个数字 _num = _str[count - (i + 1) * 3:count - i * 3] # 三个数字都不为0进行计算 if not _num == "000": s = self.__readthree(_num) res = s + " " + units[i] + " " + res # 进入下一节 i += 1 # 如果最后一节不足三个数，处理剩下的数 if count - (i * 3): s = self.__readthree(_str[0:count - (i * 3)]) res = s + " " + units[i] + " " + res # 返回结果，去掉最后的空格 return res.strip() # 私有函数，读一节（三个数字）数 def __readthree(self, _str): _str = str(int(_str)) if len(_str) == 1: return self.IntEng[_str] if len(_str) == 2: return self.__readtwo(_str) if len(_str) == 3: res = self.IntEng[_str[0]] + " " + "Hundred" if int(_str) % 100: return res + " " + self.__readtwo(_str[1:]) else: return res # 私有函数，读两位数，辅助读一节数字 def __readtwo(self, _str): _str = str(int(_str)) if int(_str) <= 20 or _str[1] == "0": return self.IntEng[_str] else: return self.IntEng[_str[0] + '0'] + " " + self.IntEng[_str[1]]
源代码文件在这里.
