pdslab/day0/cs1713-day0-prog1.c

/*
 * Copyright (C) 2020, 2019, 2018, 2017 Girish M
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 * 
 */
/*-----------------------------------
Name:Girish M
Roll number:cs1713
Date:20 July 2017
Program description: Given two positive integers, find their greatest common divisor (gcd).
Acknowledgements: Euclid's algorithm to compute gcd of two numbers
-----------------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

int gcd(int num1, int num2)
{
  if(num2 == 0)
    return num1;
  else
    return gcd(num2, num1%num2);
}

int main(int argc, char* argv[])
{
  if(argc == 3)
  {
     int num1 = atoi(argv[1]);
     int num2 = atoi(argv[2]);
     if((num1 >= 0) && (num2 >= 0))
     {
      if(num1 >= num2)
	printf("\nGCD of %d and %d is: %d\n", num1, num2, gcd(num1,num2));
      else
        printf("\nGCD of %d and %d is: %d\n", num1, num2, gcd(num2,num1));
     }
  }
  else
  {
    printf("\nUsage: ./cs1713-day0-prog1.o num1 num2\n");
  }
  return 0; 
}