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58 lines
1.3 KiB
JavaScript
58 lines
1.3 KiB
JavaScript
(function (exports) {
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'use strict';
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/**
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* Sieve of Eratosthenes.
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*
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* Simple, ancient algorithm for finding all prime numbers up to given limit.
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*
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* Returns list of primes up to specified limit.
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*
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* For example, for limit 10 it should return following list of primes:
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* [2, 3, 5, 7].
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*
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* @module primes/sieve-of-eratosthenes
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* @param {Number} limit - Algorithm will returns list of primes up to
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* specified limit.
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* @returns {Array} Will return list with all prime numbers up to provided.
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* limit.
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*
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* @example
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* var sieveOfEratosthenes =
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* require('path-to-algorithms/src/sieve-of-eratosthenes').sieveOfEratosthenes;
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*
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* console.log(sieveOfEratosthenes(12)); // [2, 3, 5, 7, 11]
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*/
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exports.sieveOfEratosthenes = function (limit) {
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var sieve = [];
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var primes = [];
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var k;
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var l;
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sieve[1] = false;
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for (k = 2; k <= limit; k += 1) {
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sieve[k] = true;
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}
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for (k = 2; k * k <= limit; k += 1) {
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if (sieve[k] !== true) {
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continue;
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}
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for (l = k * k; l <= limit; l += k) {
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sieve[l] = false;
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}
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}
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sieve.forEach(function (value, key) {
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if (value) {
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this.push(key);
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}
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}, primes);
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return primes;
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};
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}(typeof exports === 'undefined' ? window : exports));
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