/*
* rational.js - Javascript tools and libraries based around rational numbers.
* Copyright (C) 2013 Dylan Ferris
*
* This file is part of rational.js.
*
* rational.js is free software: you may redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation', 'either version 3 of the License', 'or
* (at your option) any later version.
*
* rational.js is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with rational.js. If not', 'see <http://www.gnu.org/licenses/>.
*/
/**
* @class Factorial
* @name factorial
*/
var factorial = {};
/**
* Array of factorials up to n = 100; the first 21 are integers, and the rest are strings
*
* @property PREPARED
* @type Array
* @static
* @final
*/
factorial.PREPARED = [0, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600, 6227020800, 87178291200, 1307674368000, 20922789888000, 355687428096000, 6402373705728000, 121645100408832000, 2432902008176640000, 51090942171709440000, '1124000727777607680000', '25852016738884976640000', '620448401733239439360000', '15511210043330985984000000', '403291461126605635584000000', '10888869450418352160768000000', '304888344611713860501504000000', '8841761993739701954543616000000', '265252859812191058636308480000000', '8222838654177922817725562880000000', '263130836933693530167218012160000000', '8683317618811886495518194401280000000', '295232799039604140847618609643520000000', '10333147966386144929666651337523200000000', '371993326789901217467999448150835200000000', '13763753091226345046315979581580902400000000', '523022617466601111760007224100074291200000000', '20397882081197443358640281739902897356800000000', '815915283247897734345611269596115894272000000000', '33452526613163807108170062053440751665152000000000', '1405006117752879898543142606244511569936384000000000', '60415263063373835637355132068513997507264512000000000', '2658271574788448768043625811014615890319638528000000000', '119622220865480194561963161495657715064383733760000000000', '5502622159812088949850305428800254892961651752960000000000', '258623241511168180642964355153611979969197632389120000000000', '12413915592536072670862289047373375038521486354677760000000000', '608281864034267560872252163321295376887552831379210240000000000', '30414093201713378043612608166064768844377641568960512000000000000', '1551118753287382280224243016469303211063259720016986112000000000000', '80658175170943878571660636856403766975289505440883277824000000000000', '4274883284060025564298013753389399649690343788366813724672000000000000', '230843697339241380472092742683027581083278564571807941132288000000000000', '12696403353658275925965100847566516959580321051449436762275840000000000000', '710998587804863451854045647463724949736497978881168458687447040000000000000', '40526919504877216755680601905432322134980384796226602145184481280000000000000', '2350561331282878571829474910515074683828862318181142924420699914240000000000000', '138683118545689835737939019720389406345902876772687432540821294940160000000000000', '8320987112741390144276341183223364380754172606361245952449277696409600000000000000', '507580213877224798800856812176625227226004528988036003099405939480985600000000000000', '31469973260387937525653122354950764088012280797258232192163168247821107200000000000000', '1982608315404440064116146708361898137544773690227268628106279599612729753600000000000000', '126886932185884164103433389335161480802865516174545192198801894375214704230400000000000000', '8247650592082470666723170306785496252186258551345437492922123134388955774976000000000000000', '544344939077443064003729240247842752644293064388798874532860126869671081148416000000000000000', '36471110918188685288249859096605464427167635314049524593701628500267962436943872000000000000000', '2480035542436830599600990418569171581047399201355367672371710738018221445712183296000000000000000', '171122452428141311372468338881272839092270544893520369393648040923257279754140647424000000000000000', '11978571669969891796072783721689098736458938142546425857555362864628009582789845319680000000000000000', '850478588567862317521167644239926010288584608120796235886430763388588680378079017697280000000000000000', '61234458376886086861524070385274672740778091784697328983823014963978384987221689274204160000000000000000', '4470115461512684340891257138125051110076800700282905015819080092370422104067183317016903680000000000000000', '330788544151938641225953028221253782145683251820934971170611926835411235700971565459250872320000000000000000', '24809140811395398091946477116594033660926243886570122837795894512655842677572867409443815424000000000000000000', '1885494701666050254987932260861146558230394535379329335672487982961844043495537923117729972224000000000000000000', '145183092028285869634070784086308284983740379224208358846781574688061991349156420080065207861248000000000000000000', '11324281178206297831457521158732046228731749579488251990048962825668835325234200766245086213177344000000000000000000', '894618213078297528685144171539831652069808216779571907213868063227837990693501860533361810841010176000000000000000000', '71569457046263802294811533723186532165584657342365752577109445058227039255480148842668944867280814080000000000000000000', '5797126020747367985879734231578109105412357244731625958745865049716390179693892056256184534249745940480000000000000000000', '475364333701284174842138206989404946643813294067993328617160934076743994734899148613007131808479167119360000000000000000000', '39455239697206586511897471180120610571436503407643446275224357528369751562996629334879591940103770870906880000000000000000000', '3314240134565353266999387579130131288000666286242049487118846032383059131291716864129885722968716753156177920000000000000000000', '281710411438055027694947944226061159480056634330574206405101912752560026159795933451040286452340924018275123200000000000000000000', '24227095383672732381765523203441259715284870552429381750838764496720162249742450276789464634901319465571660595200000000000000000000', '2107757298379527717213600518699389595229783738061356212322972511214654115727593174080683423236414793504734471782400000000000000000000', '185482642257398439114796845645546284380220968949399346684421580986889562184028199319100141244804501828416633516851200000000000000000000', '16507955160908461081216919262453619309839666236496541854913520707833171034378509739399912570787600662729080382999756800000000000000000000', '1485715964481761497309522733620825737885569961284688766942216863704985393094065876545992131370884059645617234469978112000000000000000000000', '135200152767840296255166568759495142147586866476906677791741734597153670771559994765685283954750449427751168336768008192000000000000000000000', '12438414054641307255475324325873553077577991715875414356840239582938137710983519518443046123837041347353107486982656753664000000000000000000000', '1156772507081641574759205162306240436214753229576413535186142281213246807121467315215203289516844845303838996289387078090752000000000000000000000', '108736615665674308027365285256786601004186803580182872307497374434045199869417927630229109214583415458560865651202385340530688000000000000000000000', '10329978488239059262599702099394727095397746340117372869212250571234293987594703124871765375385424468563282236864226607350415360000000000000000000000', '991677934870949689209571401541893801158183648651267795444376054838492222809091499987689476037000748982075094738965754305639874560000000000000000000000', '96192759682482119853328425949563698712343813919172976158104477319333745612481875498805879175589072651261284189679678167647067832320000000000000000000000', '9426890448883247745626185743057242473809693764078951663494238777294707070023223798882976159207729119823605850588608460429412647567360000000000000000000000', '933262154439441526816992388562667004907159682643816214685929638952175999932299156089414639761565182862536979208272237582511852109168640000000000000000000000', '93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000'];
/**
* Return the factorial of n as a Javascript number
*
* @param {Integer} n
* @returns {Integer} factorial of n
*/
factorial.of = function(n) {
switch (typeof factorial.PREPARED[n]) {
case 'number': return factorial.PREPARED[n];
case 'string': return parseInt(factorial.PREPARED[n]); // float approx.
}
}
if(typeof(integer) === 'object') {
/**
* Alias for {@link factorial.of}
* @function
*/
integer.factorial = factorial.of;
}
if(typeof(exports) !== 'undefined') {
exports.factorial = factorial;
}