48 lines
1.2 KiB
JavaScript
48 lines
1.2 KiB
JavaScript
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(function (exports) {
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'use strict';
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/**
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* Method will return list of all primes for provided number.
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* For example for number 18 it should return following list of primes
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* [2, 3, 3].
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*
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* @module primes/prime-factor-tree
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* @param {Number} number - Number for which method will find all primes.
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* @returns {Array} List of available primes for provided number.
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*
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* @example
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* var primeFactorTree = require('path-to-algorithms/src/prime-factor-tree')
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* .primeFactorTree;
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*
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* console.log(primeFactorTree(18)); // [2, 3, 3]
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* console.log(primeFactorTree(600851475143)); // [71, 839, 1471, 6857]
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*/
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exports.primeFactorTree = function (number) {
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var array = [];
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var s = 6;
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while (number > 1 && number % 2 === 0) {
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number /= 2;
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array.push(2);
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}
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while (number > 2 && number % 3 === 0) {
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number /= 3;
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array.push(3);
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}
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while (number > 4) {
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var p = s - 1;
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var q = s + 1;
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while (number > 4 && number % p === 0) {
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number /= p;
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array.push(p);
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}
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while (number > 4 && number % q === 0) {
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number /= q;
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array.push(q);
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}
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s += 6;
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}
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return array;
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};
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}(typeof exports === 'undefined' ? window : exports));
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