较难 通过率：23.96% 时间限制：1秒 空间限制：32M
描述
Jessi初学英语，为了快速读出一串数字，编写程序将数字转换成英文：
具体规则如下:
1.在英语读法中三位数字看成一整体，后面再加一个计数单位。从最右边往左数，三位一单位，例如12,345 等
2.每三位数后记得带上计数单位 分别是thousand, million, billion.
3.公式：百万以下千以上的数 X thousand X, 10亿以下百万以上的数：X million X thousand X, 10 亿以上的数：X billion X million X thousand X. 每个X分别代表三位数或两位数或一位数。
4.在英式英语中百位数和十位数之间要加and，美式英语中则会省略，我们这个题目采用加上and，百分位为零的话，这道题目我们省略and
下面再看几个数字例句：
1,234: one thousand two hundred and thirty four
8,088: eight thousand (and) eighty eight (注:这个and可加可不加，这个题目我们选择不加)
486,669: four hundred and eighty six thousand six hundred and sixty nine
1,652,510: one million six hundred and fifty two thousand five hundred and ten
说明：
数字为正整数，不考虑小数，转化结果为英文小写；
保证输入的数据合法
具体规则如下:
1.在英语读法中三位数字看成一整体，后面再加一个计数单位。从最右边往左数，三位一单位，例如12,345 等
2.每三位数后记得带上计数单位 分别是thousand, million, billion.
3.公式：百万以下千以上的数 X thousand X, 10亿以下百万以上的数：X million X thousand X, 10 亿以上的数：X billion X million X thousand X. 每个X分别代表三位数或两位数或一位数。
4.在英式英语中百位数和十位数之间要加and，美式英语中则会省略，我们这个题目采用加上and，百分位为零的话，这道题目我们省略and
下面再看几个数字例句：
22: twenty two
100: one hundred
145: one hundred and forty five1,234: one thousand two hundred and thirty four
8,088: eight thousand (and) eighty eight (注:这个and可加可不加，这个题目我们选择不加)
486,669: four hundred and eighty six thousand six hundred and sixty nine
1,652,510: one million six hundred and fifty two thousand five hundred and ten
说明：
数字为正整数，不考虑小数，转化结果为英文小写；
保证输入的数据合法
关键字提示：and，billion，million，thousand，hundred。
数据范围：1 \le n \le 2000000 \
输入描述：
输入一个long型整数
输出描述：
输出相应的英文写法
示例1
输入：
22输出：
twenty two
using System;
using System.Collections.Generic;
class Program
{
static void Main(string[] args)
{
string line;
while ((line = System.Console.ReadLine()) != null)
{ // 注意 while 处理多个 case
string[] groupNames = new string[] { "", "thousand", "million", "billion" };
var dic = GetDic();
string res = ReadNumber(line,dic,groupNames);
Console.WriteLine(res);
continue;
}
}
static string ReadNumber(string number, Dictionary<string, string> dic, string[] groupNames)
{
string res = string.Empty;
List<string> groups = new List<string>();
for (int i = number.Length - 3; i > -3; i -= 3)
{
if (i < 0)
{
groups.Add(number.Substring(0, 3 + i));
}
else
{
groups.Add(number.Substring(i, 3));
}
}
string group = string.Empty;
for (int i = 0; i < groups.Count; i++)
{
group = string.Empty;
if (groups[i].Length==3)
{
group = ReadThree(groups[i][0].ToString(), groups[i][1].ToString(), groups[i][2].ToString(), dic);
}
else if (groups[i].Length == 2)
{
group = ReadTwo(groups[i][0].ToString(), groups[i][1].ToString(), dic);
}
else if (groups[i].Length == 1)
{
group = ReadOne(groups[i], dic);
}
if (group != string.Empty )
{
if (i >= 1)
{
group += " " + groupNames[i];
if (res != string.Empty)
{
group += " ";
}
}
res = res.Insert(0, group);
}
}
return res;
}
static string ReadThree(string n1, string n2, string n3, Dictionary<string, string> dic)
{
string res = string.Empty;
string two = ReadTwo(n2, n3, dic);
if (n1 != "0")
{
res += dic[n1];
res += " hundred";
if (two != string.Empty)
{
res += " and " + two;
}
}
else
{
res += two;
}
return res;
}
static string ReadTwo(string n1, string n2, Dictionary<string, string> dic)
{
string res = string.Empty;
if (n1 == "0")
{
res += dic[n2];
}
else if (n1 == "1")
{
res += dic[n1 + n2];
}
else
{
res += dic[n1 + "0"];
if (n2 != "0")
{
res += " " + dic[n2];
}
}
return res;
}
static string ReadOne(string n, Dictionary<string, string> dic)
{
return dic[n];
}
static Dictionary<string, string> GetDic()
{
var dic = new Dictionary<string, string>();
dic.Add("0", "");
dic.Add("1", "one");
dic.Add("2", "two");
dic.Add("3", "three");
dic.Add("4", "four");
dic.Add("5", "five");
dic.Add("6", "six");
dic.Add("7", "seven");
dic.Add("8", "eight");
dic.Add("9", "nine");
dic.Add("10", "ten");
dic.Add("11", "eleven");
dic.Add("12", "twelve");
dic.Add("13", "thirteen");
dic.Add("14", "foutteen");
dic.Add("15", "fifteen");
dic.Add("16", "sixteen");
dic.Add("17", "seventeen");
dic.Add("18", "eighteen");
dic.Add("19", "nineteen");
dic.Add("20", "twenty");
dic.Add("30", "thirty");
dic.Add("40", "forty");
dic.Add("50", "fifty");
dic.Add("60", "sixty");
dic.Add("70", "seventy");
dic.Add("80", "eighty");
dic.Add("90", "ninety");
return dic;
}
}