careercup-中等难度 17.7

17.7 给定一个整数，打印该整数的英文描述（例如“One Thousand，Two Hundred Thirty Four”）。

解法：

举个例子，在转换19 323 984时，我们可以考虑分段处理，没三位转换一次，并在适当的地方插入“thousand”（千）和“million”（百万）。也即，

convert（19 323 984）=convert（19）+ “ million ”+convert（323）+“ thousand ”+convert（984）；

C++实现代码：

#include<iostream>
#include<string>
using namespace std;

string digits[]={"One","Two","Three","Four","Five","Six","Seven","Eight","Nine"};

string teens[]={"Eleven","Twelve","Thirteen","Fourteen","Fifteen","Sixteen","Seventeen","Eighteen","Nineteen"};

string tens[]={"Ten","Twenty","Thirty","Forty","Fifty","Sixty","Seventy","Eighty","Ninety"};

string big[]={"","Thousand","Million"};

string numToString100(int number)
{
    string str;
    if(number>)
    {
        str+=digits[number/-]+" Hundred ";
    }
    number%=;
    if(number>=&&number<=)
    {
        return str+teens[number-]+" ";
    }
    else if(number==||number>=)
    {
        str+=tens[number/-]+" ";
        number%=;
    }
    if(number>=&&number<=)
    {
        str+=digits[number-]+" ";
    }
    return str;
}
string  numToString(int number)
{
    if(number==)
    {
        return "Zero";
    }
    else if(number<)
    {
        return " Negative "+numToString(-*number);
    }
    int count=;
    string str=" ";
    while(number>)
    {
        if(number%)
        {
            str=numToString100(number%)+big[count]+" "+str;
        }
        number/=;
        count++;
    }
    return str;
}

int main()
{
    cout<<numToString();
}