Write a program to calculate the GCD of given numbers using recursion.

Dr. A.P.J. Abdul Kalam Technical University, Lucknow

KCS151 / KCS251 Programming for Problem Solving - Using C Language

Lab Exercises

22. Write a program to calculate the GCD of given numbers using recursion.

/*

 File: Prgrm22.c

 Author: Aditya Saini

 Date: Jan 17, 2021

 Description: Program to calculate the GCD of given numbers using recursion.

*/

#include <stdio.h>

int gcd_calculator (int, int);

int main (void)

{

     int num_1, num_2;

     int gcd;

     //Input number

     printf ("Input first number: ");

     scanf ("%d", &num_1);

     printf ("Input second number: ");

     scanf ("%d", &num_2);

     //Fucntion call

     gcd = gcd_calculator (num_1, num_2);

     //Print result

     printf ("Greatest Common Divisor (GCD): %d", gcd);

     return 0;

};

int gcd_calculator (int num_1, int num_2)

{

     //Calculate gcd

     //Base Case

     if (num_1 == 0)

          return num_2;

     else

          //Recursive call

          return gcd_calculator (num_2 % num_1, num_1);

};

Output

Input first number: 657

Input second number: 894

Greatest Common Divisor (GCD): 3