Skip to content

Added Miller Rabin Primality Test #1321

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open

sundaram123krishnan wants to merge 9 commits into TheAlgorithms:master

from sundaram123krishnan:master

Open

Added Miller Rabin Primality Test #1321

Changes from all commits

Commits

Show all changes

Select commit Hold shift + click to select a range

Added Miller-Rabin primality test

sundaram123krishnan May 4, 2023

Modified Miler Rabin Primality test

sundaram123krishnan May 4, 2023

Delete MillerRabinPrimaliyTest.js

sundaram123krishnan May 4, 2023

added npm format

sundaram123krishnan May 4, 2023

Merge branch 'master' of https://github.com/sundaram123krishnan/JavaS...

sundaram123krishnan May 4, 2023

modified with proper indentaion and code quality

sundaram123krishnan May 4, 2023

formatted using standard js

sundaram123krishnan May 5, 2023

deleted tasks.json

sundaram123krishnan May 5, 2023

uninstalled npm format

sundaram123krishnan May 6, 2023

File filter

Filter by extension

Conversations

Jump to

Jump to file

Failed to load files.

Loading

Diff view

Diff view

69 changes: 69 additions & 0 deletions Maths/MilerRabinPrimalityTest.js

Show comments View file Open in desktop

Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,69 @@
	/*
	* Author: Sundaram krishnan (https://github.com/sundaram123krishnan)
	* Miller–Rabin primality test : https://en.wikipedia.org/wiki/Miller%E2%80%93Rabin_primality_test#:~:text=The%20Miller%E2%80%93Rabin%20primality%20test,the%20Solovay%E2%80%93Strassen%20primality%20test.
	* Used to check whether given number is probably prime or not
	* return true if the number is probably a prime
	* else false
	*/

	/**
	* @function MillerRabin
	* @description -> Checking if a number is probably prime or not
	* @param {number} number
	* @returns {boolean} true if the number is prime, otherwise false
	*/

	const power = (base, exponent, modulus) => {
	let result = 1
	base %= modulus

	while (exponent) {
	if (exponent & 1) {
	result = (result * base) % modulus
	}
	base = (base * base) % modulus
	exponent >>= 1
	}
	return result
	}

	const checkComposite = (n, a, d, s) => {
	let x = power(a, d, n)

	if (x === 1 \|\| x === n - 1) {
	return false
	}

	for (let r = 1; r < s; r++) {
	x = (x * x) % n
	if (x === n - 1) {
	return false
	}
	}
	return true
	}

	const MillerRabin = (n, iter = 5) => {
	if (n < 4) {
	return n === 2 \|\| n === 3
	}

	let s = 0

	let d = n - 1

	while ((d & 1) === 0) {
	d >>= 1
	s++
	}

	for (let i = 0; i < iter; i++) {
	const a = 2 + (Math.floor(Math.random() * (n - 2)) % (n - 4))
	if (checkComposite(n, a, d, s)) {
	return false
	}
	}
	return true
	}

	export { MillerRabin }