Number to word conversion

This algorithm will convert a given number into English words. Like 564 will be Five Hundred and Sixty-Four. 

For this algorithm, some predefined strings are given, from that list, it will get the proper words to make into words.

The lists are like

•  Units: it will hold all words for (0 to 9) like Zero, One…Nine
•  twoDigits: it will hold all numbers from (10 - 19), like Ten, eleven…Nineteen
• tenMul: For ten multiples, (20-90), like Twenty, Thirty, … Ninety.
• tenPower: It is for Hundred and Thousands as power 2 and 3 of 10

Input and Output

Input:
The number: 568
Output:
Five Hundred And Sixty Eight

Algorithm

numToWord(num)

there are some lists which hold the words for different integers

Input: The number.

Output: Represent number into words.

Begin
   if n >= 0 and n < 10, then
      display units(n) into words
   else if n >= 10 and n < 20, then
      display twoDigitNum(n) into words         //It is from ten to nineteen
   else if n >= 20 and n <100, then
      display tensMultiple(n/10), into words
      if n mod 10 ≠ 0, then
         numToWord(n mod 10)
   else if n >= 100 and n < 1000, then
      display units(n/100), into words
      display “Hundred”, into words      //Hundred
      if n mod 100 ≠ 0, then
         display “And”
         numToWord(n mod 100)
      else if n >= 1000 and n <= 32767, then
         numToWord(n/1000)
         display “Thousand”
         if n mod 1000 ≠ 0, then
            numToWord(n mod 1000)
      else
         display invalid number and exit
End

Example

#include<iostream>
using namespace std;

string getUnit(int n) {
    //Return single digit to word
   string unit[10] = {"Zero", "One","Two", "Three","Four","Five", "Six","Seven","Eight","Nine"};
   return unit[n];
}

string getTwoDigits(int n) {
   //Here n is 2 digit number
   string td[10] = {"Ten", "Eleven","Twelve","Thirteen", "Fourteen","Fifteen","Sixteen","Seventeen","Eighteen","Nineteen"};
   return td[n%10];
}

string getTenMul(int n) {
   //Here n is multiple of 10
   string tm[8] = {"Twenty", "Thirty","Fourty", "Fifty","Sixty", "Seventy","Eighty","Ninty"};
   return tm[n-2];
}

string getTenPow(int pow) {
   //The power of ten in words
   string power[2] = {"Hundred", "Thousand"};
   return power[pow-2];
}

void printNumToWord(int n) {
   if(n >= 0 && n < 10)
      cout << getUnit(n) << " ";      //Unit values to word
   else if(n >= 10 && n < 20)
      cout << getTwoDigits(n) << " ";       //from eleven to nineteen
   else if(n >= 20 && n < 100) {
      cout << getTenMul(n/10)<<" ";
      if(n%10 != 0)
         printNumToWord(n%10); //Recursive call to convert num to word
   }else if(n >= 100 && n < 1000) {
      cout << getUnit(n/100)<<" ";
      cout <<getTenPow(2) << " ";

      if(n%100 != 0) {
         cout << "And ";
         printNumToWord(n%100);
      }

   }else if(n >= 1000 && n <= 32767) {
      printNumToWord(n/1000);
      cout <<getTenPow(3)<<" ";
      if(n%1000 != 0)
         printNumToWord(n%1000);
   }else
      printf("Invalid Input");
}

main() {
   int number;
   cout << "Enter a number between 0 to 32767: "; cin >> number;
   printNumToWord(number);
}

Output

Enter a number between 0 to 32767: 568
Five Hundred And Sixty Eight