Integer to English Practice Problem - Solution

Integer to English String Practice Problem Solution

#include <string>
#include <iostream>

using namespace std;

string num_to_text[] = { "", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen" };

string tens_to_text[] = { "", "", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety" };

string power_to_text[] = { "", "thousand", "million", "billion" };

string padIfNeeded (string ans)
{
        if ( ans == "" )
        {
                return "";
        }
        return " " + ans;
}

string translateHundred (int hundred_chunk)
{
        // handle special cases in the teens
        if ( hundred_chunk < 20 ) {
                return num_to_text[ hundred_chunk ];
        }
        int tens = hundred_chunk / 10;
        int ones = hundred_chunk % 10;
        return tens_to_text[ tens ] + padIfNeeded( num_to_text[ ones ] );
}


string translateThousand (int thousand_chunk)
{
        if ( thousand_chunk < 100 )
        {
                return translateHundred( thousand_chunk );
        }
        else
        {
                int hundreds = thousand_chunk / 100;
                int hundred_chunk = thousand_chunk % 100;
                return num_to_text[ hundreds ] + " hundred" + padIfNeeded( translateHundred( hundred_chunk ) );
        }
}
                
                
int main()
{
        int n;
        cin >> n;
        string number;
        bool is_negative = false;
        if ( n < 0 ) 
        {
                is_negative = true;
                n *= -1;
        }

        int chunk_count = 0;
        while ( n > 0 )
        {
                if ( n % 1000 != 0 ) {
                        number = translateThousand( n % 1000 ) + padIfNeeded( power_to_text[ chunk_count ] + padIfNeeded( number ) );
                }
                n /= 1000;
                chunk_count++;
        }       
        if ( number == "" )
        {
                number = "zero";
        }
        if ( is_negative )
        {
                number = "negative " + number;
        }
        cout << number << endl;
}               

Download

Many other solutions exist! If yours doesn't match the Cprogramming.com key, but it still works, let us know and we'll upload it as an alternative answer.