Day 60: Python Program to Find Lcm of Two Number Using Recursion

 

def find_lcm(a, b):

    def find_gcd(a, b):

        if b == 0:

            return a

        else:

            return find_gcd(b, a % b)

    return abs(a * b) // find_gcd(a, b)

num1 = int(input("Enter the first number: "))

num2 = int(input("Enter the second number: "))

lcm = find_lcm(num1, num2)

print(f"The LCM of {num1} and {num2} is {lcm}.")

#source code --> clcoding.com 

Code Explanation:

1. def find_lcm(a, b):

This defines a function find_lcm that takes two parameters, a and b, representing the two numbers for which we want to calculate the LCM.

2. def find_gcd(a, b):

Inside the find_lcm function, there is a nested helper function find_gcd to calculate the GCD of two numbers.

The function uses recursion:

Base Case: If b == 0, return a as the GCD.

Recursive Case: Call find_gcd(b, a % b) until b becomes 0.

This is an implementation of the Euclidean Algorithm to compute the GCD.

3. return abs(a * b) // find_gcd(a, b)

Once the GCD is determined, the formula for calculating LCM is used:

LCM

(𝑎,𝑏)=∣𝑎×𝑏∣/GCD(𝑎,𝑏)

​abs(a * b) ensures the product is non-negative (handles potential negative input).

// is used for integer division to compute the LCM.

4. num1 = int(input("Enter the first number: "))

Takes input from the user for the first number, converts it to an integer, and stores it in num1.

5. num2 = int(input("Enter the second number: "))

Takes input from the user for the second number, converts it to an integer, and stores it in num2.

6. lcm = find_lcm(num1, num2)

Calls the find_lcm function with num1 and num2 as arguments.

The LCM of the two numbers is stored in the variable lcm.

7. print(f"The LCM of {num1} and {num2} is {lcm}.")

Outputs the calculated LCM using an f-string for formatted output.