Printing an integer in english

c, integer

Solution

Ohh! This sounds like fun! No arrays and no recursion right?

So since we can't use recursion we need to build the number backwards:

#include<stdio.h>
int main(void)
{
    int num, backwards = 0, digit, backupzeros = 0;

    printf("Enter an integer ");
    scanf("%i",&num);            // get the number

    while(num > 0){
        digit = num % 10;    // pry off the last digit
        num /= 10;           // take off the digit

        if((backwards == 0) && (digit == 0))    // If it's a number that ends in 0
            backupzeros++;                   // save it, we'll use that later

        backwards = (backwards * 10) + digit; // glue it on backwards
    }

    // Now we have the number reversed. Next we need to print the digits

    while (backwards > 0){
        digit = backwards % 10;
        backwards /= 10;

        switch (digit){

        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;
        default:
                printf("zero ");
                break;
        }
    }

    while(backupzeros > 0) {
        printf("zero ");
        backupzeros--;
    }

    return 0;
}

Problem

Original source