"1 million factorial"의 두 판 사이의 차이

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(Could I have a statement, please? <a href=" http://opuqegeteymy.blog4ever.com/blog/lire-article-671222-8752076-nude_preteens.html ">Nude Preteens </a> 759 <a href=" http://yqolusaiese.blog4ever.com/b)
 
(사용자 100명 이상의 중간 판 526개는 보이지 않습니다)
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Could I have a statement, please? <a href=" http://opuqegeteymy.blog4ever.com/blog/lire-article-671222-8752076-nude_preteens.html ">Nude Preteens
+
#ril https://www.quora.com/What-is-an-efficient-algorithm-to-find-the-factorial-of-huge-numbers-which-lie-in-the-range-100000-1000000
</a>  759 <a href=" http://yqolusaiese.blog4ever.com/blog/lire-article-671218-8752042-preteen_girls.html ">Preteen Girls
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</a> eyuxk <a href=" http://ynerequjoro.blog4ever.com/blog/lire-article-671223-8752098-preteen_nudes.html ">Preteen Nudes
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== just by using [http://www.manpagez.com/man/1/bc/ bc] ==
</a> lmdr <a href=" http://fedofemugi.blog4ever.com/blog/lire-article-671225-8752118-preteen_sex_stories.html ">Preteen Sex Stories
+
rewrote a factorial function not to use recursive calling.
</a> 8]]] <a href=" http://ahaficokusamu.blog4ever.com/blog/lire-article-671217-8752030-preteen_pussy.html ">Preteen Pussy
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<syntaxhighlight lang="c">
</a> lahxt <a href=" http://nodiceduuso.blog4ever.com/blog/lire-article-671224-8752110-preteen_pics.html ">Preteen Pics
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define g(x) {
</a>  zfbwe <a href=" http://onelionura.blog4ever.com/blog/lire-article-671216-8752016-nude_preteen.html ">Nude Preteen
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    answer=1;
</a>  klr <a href=" http://ityuqefity.blog4ever.com/blog/lire-article-671220-8752056-preteen_nudist.html ">Preteen Nudist
+
    for(i=1;i<x+1;i++) {
</a>  ekersd <a href=" http://aluhadijose.blog4ever.com/blog/lire-article-671214-8751985-preteen_porn.html ">Preteen Porn
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        answer *= i;
</a>  6365 <a href=" http://oaurasytos.blog4ever.com/blog/lire-article-671221-8752068-preteen_bbs.html ">Preteen Bbs
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    }
</a>  32353
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    return answer;
 +
}
 +
 
 +
g(1000000);
 +
</syntaxhighlight>
 +
real    578m28.905s<br>
 +
user    450m56.192s<br>
 +
sys    12m33.006s<br>
 +
(with poor computing power (centOS virtual machine on windows7. i5 processor))
 +
5,565,709 digits starting <div style='word-wrap: break-word;'>82639316883312400623766461031726662911353479789638730451677758855633796110356450844465305113114639733516068042108785885414647469506478361823012109754232995901156417462491737988838926919341417654578323931987280247219893964365444552161533920583519938798941774206240841593987701818807223169252057737128436859815222389311521255279546829742282164292748493887784712443572285950934362117645254493052265841197629905619012120241419002534128319433065076207004051595915117186613844750900755834037427137686877042093751023502633401248341314910217684549431273636399066971952961345733318557782792616690299056202054369409707066647851950401003675381978549679950259346666425613978573559764142083506&hellip; </div>ending with 249,998 zeros(about 4.49% of the whole digits)
 +
* more easy way to get the number of trailing zeros(from [http://answers.yahoo.com/question/index?qid=20071017145425AAaGkd2 here])
 +
<blockquote>
 +
Every multiple of 5 contributes a zero.<br>
 +
Every multiple of 25 contributes a second zero<br>
 +
Every multiple of 125 contributes a third zero<br>
 +
Every multiple of 625 contributes a fourth zero<br>
 +
etc.<br>
 +
<br>
 +
floor(1000000/5) + floor(1000000/25) + ... floor(1000000/5^8)<br>
 +
= 200,000 + 40,000 + 8,000 +1,600 +320 + 64 +12 + 2 <br>
 +
= 249,998 trailing zeros
 +
</blockquote>
 +
* someone can get this in about only 10sec!! [http://www.makewebgames.com/showthread.php/24362-Factorial-Program-in-C-1-Million-Factorial here]<br>He's saying he used FFT
 +
== ref ==
 +
http://www.luschny.de/math/factorial/FastFactorialFunctions.htm
 +
 
 +
http://www.luschny.de/math/factorial/csharp/FactorialPrimeSwing.cs.html
 +
 
 +
http://answers.google.com/answers/threadview/id/509662.html
 +
 
 +
http://en.wikipedia.org/wiki/Elliptic_curve_factorization

2017년 6월 19일 (월) 12:19 기준 최신판

  1. ril https://www.quora.com/What-is-an-efficient-algorithm-to-find-the-factorial-of-huge-numbers-which-lie-in-the-range-100000-1000000

just by using bc

rewrote a factorial function not to use recursive calling.

define g(x) {
    answer=1;
    for(i=1;i<x+1;i++) {
        answer *= i;
    }
    return answer;
}

g(1000000);

real 578m28.905s
user 450m56.192s
sys 12m33.006s
(with poor computing power (centOS virtual machine on windows7. i5 processor))

5,565,709 digits starting

82639316883312400623766461031726662911353479789638730451677758855633796110356450844465305113114639733516068042108785885414647469506478361823012109754232995901156417462491737988838926919341417654578323931987280247219893964365444552161533920583519938798941774206240841593987701818807223169252057737128436859815222389311521255279546829742282164292748493887784712443572285950934362117645254493052265841197629905619012120241419002534128319433065076207004051595915117186613844750900755834037427137686877042093751023502633401248341314910217684549431273636399066971952961345733318557782792616690299056202054369409707066647851950401003675381978549679950259346666425613978573559764142083506…

ending with 249,998 zeros(about 4.49% of the whole digits)

  • more easy way to get the number of trailing zeros(from here)

Every multiple of 5 contributes a zero.
Every multiple of 25 contributes a second zero
Every multiple of 125 contributes a third zero
Every multiple of 625 contributes a fourth zero
etc.

floor(1000000/5) + floor(1000000/25) + ... floor(1000000/5^8)
= 200,000 + 40,000 + 8,000 +1,600 +320 + 64 +12 + 2
= 249,998 trailing zeros

  • someone can get this in about only 10sec!! here
    He's saying he used FFT

ref

http://www.luschny.de/math/factorial/FastFactorialFunctions.htm

http://www.luschny.de/math/factorial/csharp/FactorialPrimeSwing.cs.html

http://answers.google.com/answers/threadview/id/509662.html

http://en.wikipedia.org/wiki/Elliptic_curve_factorization