Added Miller Rabin Primality Test

.vscode/tasks.json

@@ -0,0 +1,16 @@
+{
+"version": "2.0.0",
+"tasks": [
+{
+"type": "npm",
+"script": "test",
+"group": {
+"kind": "build",
+"isDefault": true
+},
+"problemMatcher": [],
+"label": "npm: test",
+"detail": "jest"
+}
+]
+}

Maths/MilerRabinPrimalityTest.js

@@ -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 }

package.json

@@ -14,7 +14,8 @@
  "dependencies": {
  "@babel/core": "^7.19.3",
  "@babel/plugin-transform-runtime": "^7.19.1",
- "@babel/preset-env": "^7.19.4"
+ "@babel/preset-env": "^7.19.4",
+ "format": "^0.2.2"
  },
  "devDependencies": {
  "@babel/eslint-parser": "^7.19.1",