Programming Example

Calculate LCM using GCD

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💻 Practical Program

📘 Step by Step Learning

Program Code

public class Main {
  public static void main(String[] args) {

    int n1 = 72, n2 = 120, gcd = 1;

    for(int i = 1; i <= n1 && i <= n2; ++i) {
      // Checks if i is factor of both integers
      if(n1 % i == 0 && n2 % i == 0)
        gcd = i;
    }

    int lcm = (n1 * n2) / gcd;
    System.out.printf("The LCM of %d and %d is %d.", n1, n2, lcm);
  }
}

Output

The LCM of 72 and 120 is 360.

Explanation

This Java program calculates the Least Common Multiple (LCM) of two numbers using the GCD (Greatest Common Divisor) method.

Here's a breakdown of how the code works:

Initialization:
- Two integers n1 and n2 are initialized with values 72 and 120 respectively.
- Another integer gcd is initialized to 1, which will hold the greatest common divisor of n1 and n2.
Finding the Greatest Common Divisor (GCD):
- A for loop is used to iterate from 1 to the smaller of n1 and n2.
- Inside the loop, it checks if the current value of i is a factor of both n1 and n2. If it is, then it updates the value of gcd to i.
- After the loop, gcd will hold the greatest common divisor of n1 and n2.
Calculating the Least Common Multiple (LCM):
- LCM can be calculated using the formula: LCM = (n1 * n2) / GCD.
- Using this formula, it calculates the LCM and stores it in the variable lcm.
Output:
- Finally, it prints the calculated LCM using the printf method.
Output:
- The program prints out the calculated LCM of n1 and n2 using the printf method.

In summary, this program calculates the LCM of two given numbers (n1 and n2) using the GCD method and then prints the result.

How to learn from this program

First read the algorithm, then study the program code line by line. After that, compare the code with the output and finally go through the explanation. This approach helps learners understand both the logic and the implementation properly.

Practice suggestion

After understanding this example, try to rewrite the same program without looking at the code. Then change some values or logic and run it again. This helps improve confidence and keeps learners engaged on the page for longer.