1. Write a program in C++ that can convert a given integer value into words. Assume the largest integer value to be 999 billion
For an input of say 1108 your out should be ONE THOUSAND
ONE HUNDRED AND EIGHT

Hope this works

#include <iostream>

   #include <string>

   #include <vector>

   using namespace std;

   string digitName(int digit);

   string teenName(int number);

   string tensName(int number);

   string intName(int number);

   vector<string> ones {"","one", "two", "three", "four", "five", "six", "seven", "eight", "nine"};

   vector<string> teens {"ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen","sixteen", "seventeen", "eighteen", "nineteen"};

   vector<string> tens {"", "", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"};

   string nameForNumber (long number) {

       if (number < 10) {

           return ones[number];

       } else if (number < 20) {

           return teens [number - 10];

       } else if (number < 100) {

           return tens[number / 10] + ((number % 10 != 0) ? " " + nameForNumber(number % 10) : "");

       } else if (number < 1000) {

           return nameForNumber(number / 100) + " hundred" + ((number % 100 != 0) ? " " + nameForNumber(number % 100) : "");

       } else if (number < 1000000) {

           return nameForNumber(number / 1000) + " thousand" + ((number % 1000 != 0) ? " " + nameForNumber(number % 1000) : "");

       } else if (number < 1000000000) {

           return nameForNumber(number / 1000000) + " million" + ((number % 1000000 != 0) ? " " + nameForNumber(number % 1000000) : "");

       } else if (number < 999000000001) {

           return nameForNumber(number / 1000000000) + " billion" + ((number % 1000000000 != 0) ? " " + nameForNumber(number % 1000000000) : "");

       }

       return "error";

   }

   int main()

   {

       long input;

       do

       {

           cout << "Please enter a positive integer: ";    

           cin >> input;

           cout << "\n" << nameForNumber(input) << endl;

           cout << "\n\n" << endl;

       }while (input > 0);

       return 0;

   }