Print a long int in C using putchar() only

Q:

Write a C function print(n) that takes a long int number n as argument, and prints it on console. The only allowed library function is putchar(), no other function like itoa() or printf() is allowed. Use of loops is also not allowed.


A:

/* C program to print a long int number using putchar() only*/
#include <stdio.h>
void print(long n)
{
    // If number is smaller than 0, put a - sign and
    // change number to positive
    if (n < 0) {
        putchar('-');
        n = -n;
    }
 
    // If number is 0
    if (n == 0)
        putchar('0');
 
    // Remove the last digit and recur
    if (n/10)
        print(n/10);
 
    // Print the last digit
    putchar(n%10 + '0');
}