C#: Determine the LCM of two numbers

Last update on August 21 2025 12:54:21 (UTC/GMT +8 hours)

Write a program in C# Sharp to find the LCM of any two numbers.

Visual Presentation:

C# Sharp Exercises: Determine the LCM of two numbers

Sample Solution:

C# Sharp Code:

using System;  // Importing necessary namespace

public class Exercise45  // Declaration of the Exercise45 class
{  
    public static void Main()  // Main method, entry point of the program
    {  
        // Declaration of variables
        int i, n1, n2, max, lcm = 1;  

        // Displaying information about determining the LCM of two numbers
        Console.Write("\n\n");
        Console.Write("Determine the LCM of two numbers:\n");
        Console.Write("-----------------------------------");
        Console.Write("\n\n");	

        // Prompting user to input the first number for LCM
        Console.Write("Input 1st number for LCM: ");  
        n1 = Convert.ToInt32(Console.ReadLine());	

        // Prompting user to input the second number for LCM
        Console.Write("Input 2nd number for LCM: ");  
        n2 = Convert.ToInt32(Console.ReadLine());	

        max = (n1 > n2) ? n1 : n2;  // Determining the greater number between n1 and n2

        // Loop to find the LCM using the brute-force approach
        for (i = max;; i += max)  
        {  
            if (i % n1 == 0 && i % n2 == 0)  // Checking if i is divisible by both n1 and n2
            {  
                lcm = i;  // Updating the LCM when i is found to be divisible by both
                break;  // Exiting the loop when the LCM is found
            }  
        }  

        // Displaying the calculated LCM of the given numbers
        Console.Write("\nLCM of {0} and {1} = {2}\n\n", n1, n2, lcm);  
    }
}

Sample Output:

Determine the LCM of two numbers:                                                                           
-----------------------------------                                                                         
Input 1st number for LCM: 6                                                                                 
Input 2nd number for LCM: 8                                                                                 
LCM of 6 and 8 = 24

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