Skip to main content

Python LCM – 2 Ways to find LCM

In this article, we’ll see different ways to find LCM in Python with program examples.

Basically LCM is a smallest number that is divisible by both numbers (or all). Let us see how we can find lcm of two numbers in python.

1. Using Loop

First we find the larger number of two given numbers. Starting from it and will try to find the first number that is divisible by both, which is LCM.

x=12
y=20
if x > y:  
   greater = x  
else:  
   greater = y  
while(True):  
   if((greater % x == 0) and (greater % y == 0)):  
        lcm = greater  
        break  
   greater =  greater + 1

print ("Least common multiple = ", lcm)

Output:

Least common multiple =  60

In above program, first we’re finding greater number, then start a loop. Inside the loop we’ll find a number that can be divisible by both of given numbers n1 and n2. When we will get a that number we’ll store it into a new variable called lcm. If didn’t get then we’ll increase greater by 1. As we know the number will be greater than both of the numbers that why we’re start  checking lcm from greater number.

2. Using GCD

If you’ve the basic knowledge of mathematics, then you would know that we can find LCM very easily using GCD.

Also Read: Python GCD – 4 Ways to Find GCD or HCF

Here is the formula:

number 1 * number 2 =  LCM * GCD

So,

LCM  =   (number 1 * number 2)/GCD of number1 and 2

Let’s implement this formula into program.

import math
def get_lcm(n1,n2):
  #find gcd
  gcd = math.gcd(n1,n2)
  
  #formula 
  result = (n1*n2)/gcd
  return result
  
n1 = 12
n2  = 20

lcm = get_lcm(n1,n2)
print("least common multiple  =  ", lcm)

Output

least common multiple = 60.0

So in above program we’ve have function that receives two arguments and then inside it, first we’ll find GCD and after that we’re applying given formula to find out LCM with the help of GCD and return it.

So these were two easiest ways to get the LCM of two given numbers. But what if we have more than two numbers. So here is the program for it.

How to find LCM of more than two numbers?

from math import gcd
list1 = [12,48,8,60]   
lcm = list1[0]
for i in list1[1:]:
  lcm = int(lcm*i/gcd(lcm, i))
print("least common multiple =  ", lcm)

Output:

least common multiple =  240

So in above program, we have an list of numbers and then we will store first item of the list in variable lcm. Then we will loop through all the elements present in the list1. Inside the loop we’ll multiply lcm with i/GCD of lcm and i. So after breaking the loop we’ll get our LCM of all numbers in variable lcm.

If you’ve any problem or suggestion related to python lcm programs then please let us know in comment box.

The post Python LCM – 2 Ways to find LCM appeared first on The Crazy Programmer.



from The Crazy Programmer https://www.thecrazyprogrammer.com/2018/05/python-lcm-2-ways-to-find-lcm.html
Labels:

Comments

Post a Comment

Popular posts from this blog

dotnet sdk list and dotnet sdk latest

Can someone make .NET Core better with a simple global command? Fanie Reynders did and he did it in a simple and elegant way. I'm envious, in fact, because I spec'ed this exact thing out in a meeting a few months ago but I could have just done it like he did and I would have used fewer keystrokes! Last year when .NET Core was just getting started, there was a "DNVM" helper command that you could use to simplify dealing with multiple versions of the .NET SDK on one machine. Later, rather than 'switching global SDK versions,' switching was simplified to be handled on a folder by folder basis. That meant that if you had a project in a folder with no global.json that pinned the SDK version, your project would use the latest installed version. If you liked, you could create a global.json file and pin your project's folder to a specific version. Great, but I would constantly have to google to remember the format for the global.json file, and I'd constan...
Post a Comment
Read more

Rail Fence Cipher Program in C and C++[Encryption & Decryption]

Here you will get rail fence cipher program in C and C++ for encryption and decryption. It is a kind of transposition cipher which is also known as zigzag cipher. Below is an example. Here Key = 3. For encryption we write the message diagonally in zigzag form in a matrix having total rows = key and total columns = message length. Then read the matrix row wise horizontally to get encrypted message. Rail Fence Cipher Program in C #include<stdio.h> #include<string.h> void encryptMsg(char msg[], int key){ int msgLen = strlen(msg), i, j, k = -1, row = 0, col = 0; char railMatrix[key][msgLen]; for(i = 0; i < key; ++i) for(j = 0; j < msgLen; ++j) railMatrix[i][j] = '\n'; for(i = 0; i < msgLen; ++i){ railMatrix[row][col++] = msg[i]; if(row == 0 || row == key-1) k= k * (-1); row = row + k; } printf("\nEncrypted Message: "); for(i = 0; i < key; ++i) f...
3 comments
Read more

Data Encryption Standard (DES) Algorithm

Data Encryption Standard is a symmetric-key algorithm for the encrypting the data. It comes under block cipher algorithm which follows Feistel structure. Here is the block diagram of Data Encryption Standard. Fig1: DES Algorithm Block Diagram [Image Source: Cryptography and Network Security Principles and Practices 4 th Ed by William Stallings] Explanation for above diagram: Each character of plain text converted into binary format. Every time we take 64 bits from that and give as input to DES algorithm, then it processed through 16 rounds and then converted to cipher text. Initial Permutation: 64 bit plain text goes under initial permutation and then given to round 1. Since initial permutation step receiving 64 bits, it contains an 1×64 matrix which contains numbers from 1 to 64 but in shuffled order. After that, we arrange our original 64 bit text in the order mentioned in that matrix. [You can see the matrix in below code] After initial permutation, 64 bit text passed throug...
Post a Comment
Read more