GCD or HCF of two numbers

Q. Write a C program for finding GCD of two given numbers.

Ans.

 /*c program for finding GCD/HCF of two numbers*/

 #include<stdio.h>

 #include<conio.h>

 int main()

 {

  int n1,n2,rem;

  printf("Enter first number : ");

  scanf("%d",&n1);

  printf("Enter second number : ");

  scanf("%d",&n2);

  if(n2>n1)

  {

    n1=n1+n2;

    n2=n1-n2;

    n1=n1-n2;

  }

  do{

      rem=n1%n2;

      n1=n2;

      n2=rem;

    }while(rem!=0);

  printf("\nGCD of two number is %d",n1);
  getch();

  return 0;

 }

/************** OUTPUT ***************
Enter first number : 65
Enter second number : 45


GCD of two number is 5
**********************************/