Python Program to Find LCM of Two Numbers

Last Updated on June 30, 2023 by Mayank Dham

The term "Least Common Multiple" (LCM) refers to the smallest number that is divisible by all the given numbers in a collection of integers in mathematics. In C++, there are multiple techniques available to calculate the LCM of two numbers, such as using the "if condition," "while loop," or the GCD (Greatest Common Divisor) method, among others.

What is the LCM of two numbers in Python?

The LCM, also known as the least common multiple, is a mathematical concept used to find the smallest number (denoted as LCM(a, b) or lcm(a, b)) that is divisible by both given numbers (n1 and n2). It represents a common multiple that exists in both numbers.

Flow Chart of LCM of two numbers in Python

Algorithm of Python program to find LCM of two numbers:
Step 1: Take two inputs from the user n1 and n2
Step 2: Store the smallest common multiple of n1 and n2 into the max variable.
Step 3: Validate whether the max variable is divisible by n1 and n2, and print the max as the LCM of two numbers.
Step 4: Otherwise, the max value is updated by 1 on every iteration, and jump to step 3 to check the divisibility of the max variable.
Step 5: Terminate the program

Methods of Python Program to find LCM of two numbers

There are several methods to find the LCM (Least Common Multiple) of two numbers in Python. Here are a few commonly used approaches:

Using the GCD (Greatest Common Divisor) method:

I- mport the math module.

• Use the math.gcd() function to find the GCD of the two numbers.
• Calculate the LCM using the formula: LCM(a, b) = (a * b) / GCD(a, b).

Code Implementation:

import math

def lcm(a, b):
    gcd = math.gcd(a, b)
    lcm = (a * b) // gcd
    return lcm

Using a loop:

• Start with the larger of the two numbers.
• Use a loop to increment by the larger number until a common multiple is found.
• Check if the current number is divisible by both numbers.
• Return the first number found that satisfies this condition.

Code Implementation:

def lcm(a, b):
    max_num = max(a, b)
    while True:
        if max_num % a == 0 and max_num % b == 0:
            return max_num
        max_num += 1

Using the LCM formula:

Calculate the product of the two numbers.
Divide the product by their GCD to get the LCM.

Code Implementation:

def lcm(a, b):
    lcm = (a * b) // math.gcd(a, b)
    return lcm

These methods can be used to find the LCM of any two given numbers in Python. Choose the method that suits your requirements and preferences.

Conclusion
In conclusion, finding the LCM (Least Common Multiple) of two numbers is a common mathematical operation, and Python provides various methods to accomplish this task. By utilizing the GCD (Greatest Common Divisor), loop, or LCM formula, you can calculate the LCM efficiently. These methods offer flexibility, allowing you to choose the approach that best fits your specific requirements.

FAQs related to Python Program to Find LCM of two numbers

Here are some frequently asked questions (FAQs) related to Python Program to Find LCM of two numbers:

Q1. How can I find the LCM of two numbers in Python?
You can use methods like the GCD method, loop method, or the LCM formula to find the LCM of two numbers in Python.

Q2. What is the GCD, and how is it related to the LCM?
The GCD (Greatest Common Divisor) is the largest positive integer that divides both of the given numbers without leaving a remainder. The LCM is calculated using the GCD in some methods, such as the LCM formula.

Q3. Can I use the LCM function from a math library in Python?
Python’s math library does not have a built-in LCM function. However, you can utilize the math.gcd() function from the math library to help calculate the LCM.

Q4. Are there any Python libraries specifically designed for LCM calculations?
Although Python does not have dedicated libraries for LCM calculations, you can create your own reusable functions or import the math library for GCD calculations to find the LCM efficiently.