programming-examples/c/Basic/C Program to find Reverse of a Number using Recursion.c

/*
 * C program to find the reverse of a number using recursion
 */
#include <stdio.h>
#include <math.h>

int rev(int, int);

int main()
{
    int num, result;
    int length = 0, temp;
    printf("Enter an integer number to reverse: ");
    scanf("%d", &num);
    temp = num;
    while (temp != 0)
        {
            length++;
            temp = temp / 10;
        }
    result = rev(num, length);
    printf("The reverse of %d is %d.\n", num, result);
    return 0;
}

int rev(int num, int len)
{
    if (len == 1)
        {
            return num;
        }
    else
        {
            return (((num % 10) * pow(10, len - 1)) + rev(num / 10, --len));
        }
}