K&R Exercise 4-12.c

#include <stdio.h>
#define MAX 100

void itoa (char s[], int n, int lim)
{
    static int i = 0;

    if (n < 0) {
        s[i++] = '-';
        lim++;
        n = -n;
    }
    if (n / 10) {
        itoa (s, n / 10, lim);
    }

    if (i < (lim - 1)) {
        s[i++] = n % 10 + '0';
    }
    else {
        s[i] = n % 10 + '0';
        i = 0;
        s[lim+1] = '\0';

    }
}

int numberofdigits (n)
{
    int i=0;

    if (n < 0) {
        n = -n;
    }

    while (n != 0) {
        n = n / 10;
        i++;
    }

    return i;
}

int main ()
{
    int number = -123456789;
    char string1[MAX] = { 0 };
    char string2[MAX] = { 0 };

    itoa(string1, number, numberofdigits(number));
    printf("The string 1 is : %s\n", string1);

    number = 987654321;
    itoa(string2, number, numberofdigits(number));

    printf("The string 2 is : %s\n", string2);

        return 0;
}