Introduction to Computer Science

Introduction to Computer Science - Fall 2004 /*
Author: Yana
Module: revdig.c
What:
-------
The program prints backwards the digits of a positive integer.
Input: A positive integer.
Output: The integer printed backwards.
How:
------
Algorithm: Use a recursive solution.

#include <stdio.h>

void revdig( int n); /* function prototype */

int main (){
int n; /* Input number */
printf( "Please enter a positive number: " );
scanf(" %d ", &n);
printf( "The number printed backwards: " );
revdig(n); /* function call */
printf( "\n" );
return 0;
}

/* function definition
revdig: Print a positive integer n backwards.
Parameteres: n (input parameter).
Return value: none.
Algorithm: Recursive - print least significant digit, remove it from number,
and print remaining number backwards recursively. */
void revdig( int n)
{
if (n != 0){
printf("%d", n % 10);
revdig( n / 10 ); /* recursive call */
}
}