GCD Nonrecursive Beginner

[ronak127]

hey guys I'm a newb to this C++ programming and I need help. I've made a non-recursive GCD C++ code, but i was having problems with the algorithm. Can someone help please?

import java.util.Scanner;
public class GCD
{
public static int GCD;
public static int div;
public static int remainder = 1;

public static void main(String [] args)
{
int num2;

Scanner keyboard = new Scanner(System.in);
do{
//Prompting for first number
System.out.println("Enter the first number: ");
int num1 = keyboard.nextInt();

//Exit
if(num1 <= 0)
{
System.exit(0);
}//Ending of if

//Prompting for second number
System.out.println("Enter the second number: ");
num2 = keyboard.nextInt();

div = num1 / num2;
remainder = num1 % num2;

if (num1 < num2)
{
div = num1;
num1 = num2;
num2 = div;
}

while(remainder != 0)
{
div = num1 / num2;
remainder = num1 % num2;
num1 = num2;
num2 = remainder;
}
num2 = GCD;

System.out.println("The GCD is: " + GCD);
} while (GCD >= 0);


}//Ending bracket of method main
}//Ending bracket of class

[gerard4143]

I say you need help, this is Java.

[ronak127]

excuse me it was suppose to say Java.. sorry i had someone else put this thread up for me

[firstPerson]

div = num1 / num2;    
            remainder = num1 % num2;

1)Let num1 = 6 and num2 = 3. Then div = 6/3 = 2. and the remainder 6%3 = 0.
2)
if (num1 < num2)
{
div = num1;
num1 = num2;
num2 = div;
}
This is irrelevant in the above case since num1 > num2. So its skipped.

3)
while(remainder != 0)
{
div = num1 / num2;
remainder = num1 % num2;
num1 = num2;
num2 = remainder;
}
num2 = GCD;
Since remainder is 0, this won't get executed and num2 is set to GCD which you haven't defined, so it will be 0. You see your problem?