C Program to print the two digit number in words

The program consists of two outer switch statements. The first switch statement prints the word for the first digit and the second switch case statement print the word for the second digit.

In first switch case, we have used another nested switch case to handle the numbers from 11 to 19 because require some trick to print these numbers.

#include <stdio.h>
int main(void)
{
    int firstDigit, secondDigit;
    printf("Enter a two-digit number: ");
    scanf("%1d%1d", &firstDigit, &secondDigit);
    printf("You have entered: ");
    // print word for the first digit
    switch (firstDigit)
    {
    case 1:
        // special case for numbers between 11-19
        switch (secondDigit)
        {
        case 0:
            printf("ten");
            return 0;
        case 1:
            printf("eleven");
            return 0;
        case 2:
            printf("twelve");
            return 0;
        case 3:
            printf("thirteen");
            return 0;
        case 4:
            printf("fourteen");
            return 0;
        case 5:
            printf("fifteen");
            return 0;
        case 6:
            printf("sixteen");
            return 0;
        case 7:
            printf("seventeen");
            return 0;
        case 8:
            printf("eigthteen");
            return 0;
        case 9:
            printf("nineteen");
            return 0;
        }
    case 2:
        printf("twenty");
        break;
    case 3:
        printf("thirty");
        break;
    case 4:
        printf("forty");
        break;
    case 5:
        printf("fifty");
        break;
    case 6:
        printf("sixty");
        break;
    case 7:
        printf("seventy");
        break;
    case 8:
        printf("eighty");
        break;
    case 9:
        printf("ninety");
        break;
    }
    // print word for the second digit
    switch (secondDigit)
    {
    case 1:
        printf("-one");
        break;
    case 2:
        printf("-two");
        break;
    case 3:
        printf("-three");
        break;
    case 4:
        printf("-four");
        break;
    case 5:
        printf("-five");
        break;
    case 6:
        printf("-six");
        break;
    case 7:
        printf("-seven");
        break;
    case 8:
        printf("-eight");
        break;
    case 9:
        printf("-nine");
        break;
    }
    return 0;
}

Output:

Enter a two-digit number: 11
You have entered: eleven