Jan 12, 2025 · May 25, 2024 · May 25, 2024 · May 25, 2024 · Jan 8, 2025 · Jan 8, 2025
diff --git a/DIRECTORY.md b/DIRECTORY.md
  * [RowEchelon](Maths/RowEchelon.js)
  * [ShorsAlgorithm](Maths/ShorsAlgorithm.js)
  * [SieveOfEratosthenes](Maths/SieveOfEratosthenes.js)
  * [SieveOfEratosthenesIntArray](Maths/SieveOfEratosthenesIntArray.js)
  * [Signum](Maths/Signum.js)
  * [SimpsonIntegration](Maths/SimpsonIntegration.js)
  * [Softmax](Maths/Softmax.js)
diff --git a/Maths/SieveOfEratosthenes.js b/Maths/SieveOfEratosthenes.js
 const sieveOfEratosthenes = (n) => {
  /*
   * Calculates prime numbers till a number n
   * :param n: Number up to which to calculate primes
   * :return: A boolean list containing only primes
   */
  const primes = new Array(n + 1)
  primes.fill(true) // set all as true initially
  primes[0] = primes[1] = false // Handling case for 0 and 1
  const sqrtn = Math.ceil(Math.sqrt(n))
  for (let i = 2; i <= sqrtn; i++) {
    if (primes[i]) {
      for (let j = i * i; j <= n; j += i) {
        /*
        Optimization.
        Let j start from i * i, not 2 * i, because smaller multiples of i have been marked false.
 /**
 * @function sieveOfEratosthenes
 * @description Function to get all the prime numbers below a given number using sieve of eratosthenes algorithm
 * @param {Number} max The limit below which all the primes are required to be
 * @returns {Number[]} An array of all the prime numbers below max
 * @see [Sieve of Eratosthenes](https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes)
 * @example
 * sieveOfEratosthenes(1) // ====> []
 * @example
 * sieveOfEratosthenes(20) // ====> [2, 3, 5, 7, 11, 13, 17, 19]
 *
 */
 function sieveOfEratosthenes(max) {
  const sieve = []
  const primes = []

        For example, let i = 4.
        We do not have to check from 8(4 * 2) to 12(4 * 3)
        because they have been already marked false when i=2 and i=3.
        */
        primes[j] = false
  for (let i = 2; i <= max; ++i) {
    if (!sieve[i]) {
      // If i has not been marked then it is prime
      primes.push(i)
      for (let j = i << 1; j <= max; j += i) {
        // Mark all multiples of i as non-prime
        sieve[j] = true
      }
    }
  }
diff --git a/Maths/SieveOfEratosthenesIntArray.js b/Maths/SieveOfEratosthenesIntArray.js
diff --git a/Maths/test/SieveOfEratosthenes.test.js b/Maths/test/SieveOfEratosthenes.test.js
 import { sieveOfEratosthenes } from '../SieveOfEratosthenes'
 import { PrimeCheck } from '../PrimeCheck'

 describe('should return an array of prime booleans', () => {
  it('should have each element in the array as a prime boolean', () => {
    const n = 30
    const primes = sieveOfEratosthenes(n)
    primes.forEach((primeBool, index) => {
      if (primeBool) {
        expect(PrimeCheck(index)).toBeTruthy()
      }
    })

 describe('sieveOfEratosthenes', () => {
  test('returns an empty array for max < 2', () => {
    expect(sieveOfEratosthenes(1)).toEqual([])
  })

  test('returns [2] for max = 2', () => {
    expect(sieveOfEratosthenes(2)).toEqual([2])
  })

  test('returns [2, 3] for max = 3', () => {
    expect(sieveOfEratosthenes(3)).toEqual([2, 3])
  })

  test('returns [2, 3, 5, 7] for max = 10', () => {
    expect(sieveOfEratosthenes(10)).toEqual([2, 3, 5, 7])
  })

  test('returns [2, 3, 5, 7, 11, 13, 17, 19] for max = 20', () => {
    expect(sieveOfEratosthenes(20)).toEqual([2, 3, 5, 7, 11, 13, 17, 19])
  })

  test('returns [2, 3, 5, 7, 11, 13, 17, 19, 23, 29] for max = 30', () => {
    expect(sieveOfEratosthenes(30)).toEqual([
      2, 3, 5, 7, 11, 13, 17, 19, 23, 29
    ])
  })
 })
diff --git a/Maths/test/SieveOfEratosthenesIntArray.test.js b/Maths/test/SieveOfEratosthenesIntArray.test.js
diff --git a/Project-Euler/Problem035.js b/Project-Euler/Problem035.js
 *
 * @author ddaniel27
 */
 import { sieveOfEratosthenes } from '../Maths/SieveOfEratosthenesIntArray'
 import { sieveOfEratosthenes } from '../Maths/SieveOfEratosthenes'

 function problem35(n) {
  if (n < 2) {
Original file line number	Diff line number	Diff line change
Expand Up		@@ -254,7 +254,6 @@
		* [RowEchelon](Maths/RowEchelon.js)
		* [ShorsAlgorithm](Maths/ShorsAlgorithm.js)
		* [SieveOfEratosthenes](Maths/SieveOfEratosthenes.js)
		* [SieveOfEratosthenesIntArray](Maths/SieveOfEratosthenesIntArray.js)
		* [Signum](Maths/Signum.js)
		* [SimpsonIntegration](Maths/SimpsonIntegration.js)
		* [Softmax](Maths/Softmax.js)
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Original file line number	Diff line number	Diff line change
		@@ -1,25 +1,26 @@
		const sieveOfEratosthenes = (n) => {
		/*
		* Calculates prime numbers till a number n
		* :param n: Number up to which to calculate primes
		* :return: A boolean list containing only primes
		*/
		const primes = new Array(n + 1)
		primes.fill(true) // set all as true initially
		primes[0] = primes[1] = false // Handling case for 0 and 1
		const sqrtn = Math.ceil(Math.sqrt(n))
		for (let i = 2; i <= sqrtn; i++) {
		if (primes[i]) {
		for (let j = i * i; j <= n; j += i) {
		/*
		Optimization.
		Let j start from i * i, not 2 * i, because smaller multiples of i have been marked false.
		/**
		* @function sieveOfEratosthenes
		* @description Function to get all the prime numbers below a given number using sieve of eratosthenes algorithm
		* @param {Number} max The limit below which all the primes are required to be
		* @returns {Number[]} An array of all the prime numbers below max
		* @see [Sieve of Eratosthenes](https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes)
		* @example
		* sieveOfEratosthenes(1) // ====> []
		* @example
		* sieveOfEratosthenes(20) // ====> [2, 3, 5, 7, 11, 13, 17, 19]
		*
		*/
		function sieveOfEratosthenes(max) {
		const sieve = []
		const primes = []

		For example, let i = 4.
		We do not have to check from 8(4 * 2) to 12(4 * 3)
		because they have been already marked false when i=2 and i=3.
		*/
		primes[j] = false
		for (let i = 2; i <= max; ++i) {
		if (!sieve[i]) {
		// If i has not been marked then it is prime
		primes.push(i)
		for (let j = i << 1; j <= max; j += i) {
		// Mark all multiples of i as non-prime
		sieve[j] = true
		}
		}
		}
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Original file line number	Diff line number	Diff line change
		@@ -1,14 +1,29 @@
		import { sieveOfEratosthenes } from '../SieveOfEratosthenes'
		import { PrimeCheck } from '../PrimeCheck'

		describe('should return an array of prime booleans', () => {
		it('should have each element in the array as a prime boolean', () => {
		const n = 30
		const primes = sieveOfEratosthenes(n)
		primes.forEach((primeBool, index) => {
		if (primeBool) {
		expect(PrimeCheck(index)).toBeTruthy()
		}
		})

		describe('sieveOfEratosthenes', () => {
		test('returns an empty array for max < 2', () => {
		expect(sieveOfEratosthenes(1)).toEqual([])
		})

		test('returns [2] for max = 2', () => {
		expect(sieveOfEratosthenes(2)).toEqual([2])
		})

		test('returns [2, 3] for max = 3', () => {
		expect(sieveOfEratosthenes(3)).toEqual([2, 3])
		})

		test('returns [2, 3, 5, 7] for max = 10', () => {
		expect(sieveOfEratosthenes(10)).toEqual([2, 3, 5, 7])
		})

		test('returns [2, 3, 5, 7, 11, 13, 17, 19] for max = 20', () => {
		expect(sieveOfEratosthenes(20)).toEqual([2, 3, 5, 7, 11, 13, 17, 19])
		})

		test('returns [2, 3, 5, 7, 11, 13, 17, 19, 23, 29] for max = 30', () => {
		expect(sieveOfEratosthenes(30)).toEqual([
		2, 3, 5, 7, 11, 13, 17, 19, 23, 29
		])
		})
		})
Original file line number	Diff line number	Diff line change
Expand Up		@@ -9,7 +9,7 @@
		*
		* @author ddaniel27
		*/
		import { sieveOfEratosthenes } from '../Maths/SieveOfEratosthenesIntArray'
		import { sieveOfEratosthenes } from '../Maths/SieveOfEratosthenes'

		function problem35(n) {
		if (n < 2) {
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