C Program to find Reverse of a Number using Recursion

Advertisements
The following C program using recursion reverses the digits of the number and displays it on the output of the terminal.Eg: 123 becomes 321.

Here is the source code of the C program to find the reverse of a number. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

  1. /*
  2.  * C program to find the reverse of a number using recursion
  3.  */
  4. #include <stdio.h>
  5. #include <math.h>
  6.  
  7. int rev(int, int);
  8.  
  9. int main()
  10. {
  11.     int num, result;
  12.     int length = 0, temp;
  13.  
  14.     printf("Enter an integer number to reverse: ");
  15.     scanf("%d", &num);
  16.     temp = num;
  17.     while (temp != 0)
  18.     {
  19.         length++;
  20.         temp = temp / 10;
  21.     }
  22.     result = rev(num, length);
  23.     printf("The reverse of %d is %d.\n", num, result);
  24.     return 0;
  25. }
  26.  
  27. int rev(int num, int len)
  28. {
  29.     if (len == 1)
  30.     {
  31.         return num;
  32.     }
  33.     else
  34.     {
  35.         return (((num % 10) * pow(10, len - 1)) + rev(num / 10, --len));
  36.     }
  37. }


$ cc pgm34.c
$ a.out
Enter an integer number to reverse: 1234
The reverse of 1234 is 4321.

Sanfoundry Global Education & Learning Series – 1000 C Programs.

Here’s the list of Best Reference Books in C Programming, Data-Structures and Algorithms

If you wish to look at other example programs on Simple C Programs, go to Simple C Programs. If you wish to look at programming examples on all topics, go to C Programming Examples.
Advertisements
Subscribe Newsletter & Posts

Manish Bhojasia, a technology veteran with 17+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer and SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage & Cluster Administration, Advanced C Programming, SAN Storage Technologies, SCSI Internals and Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him below.

Practice Interview Questions & Answers, Quizzes, Objective, Multiple Choice Aptitude Tests for Freshers and Experienced People in these topics - Learn C, C++, Java and C# Programming with coding example on Simple problems as well as tough Algorithms and Data-structures along with runtime output: - C Programs, Data-Structures and Algorithms, C++ Algorithms, Java Algorithms, C# Programs, Android Programs in Java

C Tutorials and Linux Commands Tutorial - C Tutorials, Linux Commands

Career Mentoring with our Founder / CTO - Read More
Advertisements

Follow Manish & Sanfoundry