Java Program to find LCM of Two Numbers

Write a Java Program to find LCM of Two Numbers using While Loop and recursive method. According to Mathematics, LCM (Least Common Multiple) of two or more integers is the smallest positive integer that is divisible by the assigned integer values (without remainder).

For example, the LCM of 2 and 3 is 6 because 6 is the smallest positive integer that is divisible by both 2 and 3.

Java Program to find LCM of Two Numbers using While Loop

This Java program allows the user to enter two positive integer values. Next, in this program, we are using the While Loop and a temporary variable to calculate the LCM of those two positive integers.

import java.util.Scanner;

public class LMofTwo1 {
	private static Scanner sc;
	public static void main(String[] args) 
	{
		int Num1, Num2, Temp, GCD = 0, LM = 0;
		sc = new Scanner(System.in);
		
		System.out.print(" Please Enter the First Integer Value : ");
		Num1 = sc.nextInt();	
		
		System.out.print(" Please Enter the Second Integer Value : ");
		Num2 = sc.nextInt();
		
		int a = Num1;
		int b = Num2;
		
		while(Num2 != 0)
	    {
			Temp = Num2;
			Num2 = Num1 % Num2;
			Num1 = Temp;
	    }
		GCD = Num1;
		System.out.println("\n GCD of " + a + " and " + b + "  =  " + GCD);
		
		LM = (a * b) / GCD;
		System.out.println("\n LCM of " + a + " and " + b + "  =  " + LM);
		
	}
}
 Please Enter the First Integer Value : 2
 Please Enter the Second Integer Value : 3

 GCD of 2 and 3  =  1

 LCM of 2 and 3  =  6

LCM of Two Numbers without using Temp

This program calculates the Least Common Multiple without using any temporary variable.

import java.util.Scanner;

public class LCMofTwo2 {
	private static Scanner sc;
	public static void main(String[] args) 
	{
		int Num1, Num2, GCD = 0, LCM = 0;
		sc = new Scanner(System.in);
	
		System.out.print(" Please Enter the First Integer Value : ");
		Num1 = sc.nextInt();	
	
		System.out.print(" Please Enter the Second Integer Value : ");
		Num2 = sc.nextInt();
	
		int a = Num1;
		int b = Num2;
	
		while(Num2 != 0)
	    {
			if(Num1 > Num2)
			{
				Num1 = Num1 - Num2;
			}
			else
			{
				Num2 = Num2 - Num1;
			}
	    }
		GCD = Num1;
		System.out.println("\n GCD of " + a + " and " + b + "  =  " + GCD);
	
		LCM = (a * b) / GCD;
		System.out.println("\n LCM of " + a + " and " + b + "  =  " + LCM);
	}
}
Java Program to find LCM of Two Numbers 2

LCM of Two Numbers using Recursive Function

This program for lcm of two numbers calculates the Greatest Common Divisor by calling the HCFofTwo function recursively. Next, this program finds the Least Common Multiple from GCD.

import java.util.Scanner;

public class LMofTwo3 {
	private static Scanner sc;
	public static void main(String[] args) 
	{
		int Num1, Num2, GCD = 0, LM = 0;
		sc = new Scanner(System.in);
		
		System.out.print(" Please Enter the First Integer Value : ");
		Num1 = sc.nextInt();	
		
		System.out.print(" Please Enter the Second Integer Value : ");
		Num2 = sc.nextInt();
		
		GCD = HCFofTwo(Num1, Num2);		
		System.out.println("\n GCD of " + Num1 + " and " + Num2 + "  =  " + GCD);
		
		LM = (Num1 * Num2) / GCD;
		System.out.println("\n LCM of " + Num1 + " and " + Num2 + "  =  " + LM);
	}
	public static int HCFofTwo(int Num1, int Num2)
	{
		if(Num2 == 0)
		{
			return Num1;
		}
		else
		{
			return HCFofTwo(Num2, Num1 % Num2);
		}
	}
}
 Please Enter the First Integer Value : 100
 Please Enter the Second Integer Value : 150

 GCD of 100 and 150  =  50

 LCM of 100 and 150  =  300