Java Program To Find LCM for Two Large Numbers

1.Overview

In this short article, you'll learn how to find the LCM for two large numbers. Here, we are going to use BigInteger class to hold the large values.

Example:

large value 1: 123456789123456789123456

large value 2: 987654321987654321987654

Output lcm : 20322105226083421931844602115480285409718968704

2. Example To Find LCM for Large Numbers

Let us use the two BigInteger object to hold the large values.

This BigInteger class has gcd() method which returns GCD for two numbers.

Next, use multiply() method to get the multiplication of two numbers.

Finally, use the formula LCM = large 1 * large 2 / gcd(large1 * large 2)

package com.javaprogramto.programs.maths;

import java.math.BigInteger;

public class LCMOfLargeNumbers {

	public static void main(String[] args) {
		
		BigInteger large1 = new BigInteger("123456789123456789123456");
		BigInteger large2 = new BigInteger("987654321987654321987654");

		BigInteger gcd = large1.gcd(large2);
		
		BigInteger multiply = large1.multiply(large2);
		
		BigInteger lcm = multiply.divide(gcd);
		
		System.out.println("Final LCM output: "+lcm.toString());
	
	}
}

Output:

Final LCM output: 20322105226083421931844602115480285409718968704

3. Conclusion

In this article, you've seen how to find the right lcm for bigger values using BigInteger class methods.

BigInteger API

GitHub Example

Finding LCM In 2 Ways in Java With Simple Example Programs

1. Overview

In this short article, you'll learn how to find the LCM of two numbers in java by using simple while loop and by using GCD of same numbers.

It is easy to understand if you know the below topics.

If else condition

while loop

LCM means least common multiple - In other words a minimum number that is divisible by given two numbers without any remainder.

Example

Input : a = 12, b = 40

Multiple factors are : 2, 2, 3, 10

LCM is : 2 * 2 * 3 * 10 = 120

Java Program to Print Multiplication Table For Given Number

1. Overview

In this article, you'll learn how to generate and print multiplication table in java for a given number. This can be done using for loop and while or do while loops.

Knowledge on the below topics is required to understand the examples in this post.

for loops 

while and dowhile loops

2. Generate Multiplication Table Using For Loop

Simple example program to create multiplication of any given number with help of for loop.

package com.javaprogramto.programs;

public class MultiplicationTableForLoop {

	public static void main(String[] args) {
		int tableNumber = 10;

		System.out.println("Generating the table 10");
		// generating table 10
		for (int i = 1; i <= 10; i++) {

			System.out.format("%d * %d = %d \n", tableNumber, i, tableNumber * i);

		}

		// generating the 20 table.
		System.out.println("\nGenerating the table 20");
		int anotherTableNumber = 20;
		for (int i = 1; i <= 10; i++) {

			System.out.format("%d * %d = %d \n", anotherTableNumber, i, anotherTableNumber * i);

		}

	}

}

Output:

Generating the table 10
10 * 1 = 10 
10 * 2 = 20 
10 * 3 = 30 
10 * 4 = 40 
10 * 5 = 50 
10 * 6 = 60 
10 * 7 = 70 
10 * 8 = 80 
10 * 9 = 90 
10 * 10 = 100 

Generating the table 20
20 * 1 = 20 
20 * 2 = 40 
20 * 3 = 60 
20 * 4 = 80 
20 * 5 = 100 
20 * 6 = 120 
20 * 7 = 140 
20 * 8 = 160 
20 * 9 = 180 
20 * 10 = 200 

3. Generate Multiplication Table Using While Loop

Next examples is using while loop running from 1 to 10.

public class MultiplicationTableWhileLoop {

	public static void main(String[] args) {
		int tableNumber = 5;

		System.out.println("Generating the table 9");
		int tableStartIndex = 1;
		int tableEndIndex = 10;
		// generating table 10
		while (tableStartIndex <= tableEndIndex) {

			System.out.format("%d * %d = %d \n", tableNumber, tableStartIndex, tableNumber * tableStartIndex);
			tableStartIndex++;
		}

		// generating the 20 table.
		System.out.println("\nGenerating the table 18");

		// resetting the start and end index
		tableStartIndex = 1;
		tableEndIndex = 10;
		int anotherTableNumber = 18;
		while (tableStartIndex <= tableEndIndex) {

			System.out.format("%d * %d = %d \n", anotherTableNumber, tableStartIndex, tableNumber * tableStartIndex);
			tableStartIndex++;
		}

	}

}

Output:

Generating the table 9
5 * 1 = 5 
5 * 2 = 10 
5 * 3 = 15 
5 * 4 = 20 
5 * 5 = 25 
5 * 6 = 30 
5 * 7 = 35 
5 * 8 = 40 
5 * 9 = 45 
5 * 10 = 50 

Generating the table 18
18 * 1 = 5 
18 * 2 = 10 
18 * 3 = 15 
18 * 4 = 20 
18 * 5 = 25 
18 * 6 = 30 
18 * 7 = 35 
18 * 8 = 40 
18 * 9 = 45 
18 * 10 = 50 

4. Conclusion

In this short article, you've seen the easy engineering program to print the multiplication table in java with the help of for and while loops.

How to multiply two numbers in java?

GitHub For Loop

GitHub While Loop

Java Program to Find All Roots of a Quadratic Equation Using Formula

1. Overview

In this article, you'll learn how to find all the roots of a given quadratic equation using java programming language.

We'll use the if else condition and Math.sqrt() method to solve this problem.

You can look the best way to find the largest number among three numbers

Example:

Sample quadratic equation ax² + by + c = 0

and here a, b and c are the real numbers where a !=  0.

First, we need to find the determinant of the quadratic equation. 

Formula for the determinant is b² - 4ac.

Result of this equation tells the nature of the roots.

• If determinant is greater than 0, the roots are real and different.
• If determinant is equal to 0, the roots are real and equal.
• If determinant is less than 0, the roots are complex and different.