Write code to convert given number into words (eg 1234 as input should output one thousand two hundred and thirty four)

Question

Write C/C++/Java code to convert given number into words.

eg:- Input: 1234

Output: One thousand two hundred thirty-four.

Input: 10

Output: Ten

Answer 1

/* This Program will convert Numbers from -999,999,999 to 999,999,999 into words */

#include 
#include 
#include 
#include 

using namespace std;

const std::vector first14 = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen" };
const std::vector prefixes = { "twen", "thir", "for", "fif", "six", "seven", "eigh", "nine" };

std::string inttostr(const int number)
{
    if (number < 0)
    {
        return "minus " + inttostr(-number);
    }
    if (number <= 14)
        return first14.at(number);
    if (number < 20)
        return prefixes.at(number - 12) + "teen";
    if (number < 100) {
        unsigned int remainder = number - (static_cast(number / 10) * 10);
        return prefixes.at(number / 10 - 2) + (0 != remainder ? "ty " + inttostr(remainder) : "ty");
    }
    if (number < 1000) {
        unsigned int remainder = number - (static_cast(number / 100) * 100);
        return first14.at(number / 100) + (0 != remainder ? " hundred " + inttostr(remainder) : " hundred");
    }
    if (number < 1000000) {
        unsigned int thousands = static_cast(number / 1000);
        unsigned int remainder = number - (thousands * 1000);
        return inttostr(thousands) + (0 != remainder ? " thousand " + inttostr(remainder) : " thousand");
    }
    if (number < 1000000000) {
        unsigned int millions = static_cast(number / 1000000);
        unsigned int remainder = number - (millions * 1000000);
        return inttostr(millions) + (0 != remainder ? " million " + inttostr(remainder) : " million");
    }
    throw std::out_of_range("inttostr() value too large");
}

int main()
{
    int num;
    cout << "Enter a number to convert it into letters : ";
    cin >> num;
    cout << endl << num << " = " << inttostr(num) << endl;
    system("pause");
    return 0;
}