C Program to Find GCD of given Numbers using Recursion

This C program, using recursion, finds the GCD of the two numbers entered by the user. The user enters two numbers by using a space in between them or by pressing enter after each input.

Here is the source code of the C program to display a linked list in reverse. 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 GCD of given Numbers using Recursion
  3.  */
  4. #include <stdio.h>
  6. int gcd(int, int);
  8. int main()
  9. {
  10.     int a, b, result;
  12.     printf("Enter the two numbers to find their GCD: ");
  13.     scanf("%d%d", &a, &b);
  14.     result = gcd(a, b);
  15.     printf("The GCD of %d and %d is %d.\n", a, b, result);
  16. }
  18. int gcd(int a, int b)
  19. {
  20.     while (a != b)
  21.     {
  22.         if (a > b)
  23.         {
  24.             return gcd(a - b, b);
  25.         }
  26.         else
  27.         {
  28.             return gcd(a, b - a);
  29.         }
  30.     }
  31.     return a;
  32. }}

$ gcc gcd_recr.c -o gcd_recr
$ a.out
Enter the two numbers to find their GCD: 100 70
The GCD of 100 and 70 is 10.

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If you wish to look at other example programs on Mathematical Functions, go to C Programming Examples on Mathematical Functions. If you wish to look at programming examples on all topics, go to C Programming Examples.
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