1!+2!+3!+4!+...+100! 多语言版纯娱乐 - 闲聊灌水

zklhp

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已结贴√ 问题点数：100 回复次数：24

1!+2!+3!+4!+...+100! 多语言版纯娱乐

需要知道结果就试了试我在linux下装的这些软件总结一下
C语言当然简单起见用了浮点数。。。

程序代码：

//gcc -Wall -O3 a.c
#include <stdio.h>
int main(void)
{
    double sum = 0.0;
    double f = 1.0;
    int i = 1;
    int j = 1;
    for (i = 1; i <= 100; i++)
    {
        f = 1.0;
        for (j = 1; j <= i; j++)
        {
            f *= j;
        }
        sum += f;
    }
    printf("%lf\n", sum);
    return 0;
}

time ./a.out
94269001683709925420719656762546985486727416355083585338645224398394941811201963496134808913580530755456740099840414271964178383003109887091841526063934996480.000000
real    0m0.002s
user    0m0.000s
sys    0m0.000s

不用想这个肯定快但要是写成大数运算就稍微麻烦点这里就当成浮点写了。。

python 实际是python 2.7

程序代码：

#!/usr/bin/python2
i = 1
f = 0
sum = 0
while i <= 100:
    sum += reduce(lambda x, y: x * y, xrange(1, i + 1))
    i += 1
print sum

time ./a.py
94269001683709979260859834124473539872070722613982672442938359305624678223479506023400294093599136466986609124347432647622826870038220556442336528920420940313
real    0m0.038s
user    0m0.033s
sys    0m0.007s

效率也挺好的关键直接就是大数运算

bc 一个linux下的命令行计算程序支持类C的语法大数运算我非常喜欢的一个小工具 windows下我也用试试它的表现

程序代码：

i = 1
j = 1
f = 1
sum = 0
for (i = 1; i <= 100; i++)
{
    f = 1
    for (j = 1; j <= i; j++)
    {
        f *= j
    }
    sum += f
}
sum

time cat a.bc | bc
94269001683709979260859834124473539872070722613982672442938359305624\
67822347950602340029409359913646698660912434743264762282687003822055\
6442336528920420940313
real    0m0.011s
user    0m0.003s
sys    0m0.007s

很好很好虽然结果输出比较难看但结果很好而且写起来和C的感觉差不多

matlab 我这里用的是开源替代GNU Octave 对我这个没学过matlab的人来说这玩意就相当于matlab了

sum(factorial(1:100))

神一样的一行代码

time ./a.m
GNU Octave, version 3.6.3
Copyright (C) 2012 John W. Eaton and others.
This is free software; see the source code for copying conditions.
There is ABSOLUTELY NO WARRANTY; not even for MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  For details, type `warranty'.
Octave was configured for "x86_64-unknown-linux-gnu".
Additional information about Octave is available at http://www.
Please contribute if you find this software useful.
For more information, visit http://www.
Read http://www. to learn how to submit bug reports.
For information about changes from previous versions, type `news'.
ans =  9.4269e+157
real    0m0.181s
user    0m0.160s
sys    0m0.017s

我这还有R 不过考虑到它的长处不是在计算上面不测试了

总结
1 python内置的大数运算不错直接写就是大数运算了
2 octave或者说是matlab的语法好简洁一行解决问题但受限于octave 貌似没法做高精度的运算
3 bc好厉害啊以后就用它了。。

这里比的不大公平因为程序启动的时间也统计了但这个比较也是贴近实际的

以上的几个的几个东东我都是初学如有不当欢迎批评

/************************************************************************/

改成到1000! 让python和bc比比速度。。

time ./a.py
402790050531223457680670558292183044930441094551528966419334642920075902370082550849878938011122874840322664395727767319128483846892726398968790560901035018977865543415443376965144616549510538851077440410165819782073475583082079396504111380884916810768467471317168913183948275897490803646698793846190852594417739671786914563472162093180956284720843607311204509397095907530114810381703803860648328656344389023077975647748628886817466804724858587747840936784462436173977429991182753207302348016538494642001301432395279726745538178727708503090870745742249581124437084158031806471602854863650302741825130214652788342621283870175833906572656890104432413095171095723550851047360182700817666447833450097928957386876271765554137407111747666512309980678539886786878262902584539118231519316835523885400137767203426696953126303292828224235349134630280084480064650497764755473824102259453127730077777531063115138764952527597098445380046443997540925880086936317933421768424925084707414812932329166745886234137226923024813461900363225999464524935227947647167947434411637139203517404371214232998239493954562323327076903915931443305369962856388265027346155623332543302943446674383336900484885947609695640139797208838438493998636482572950930777919644406154624084228042985270573774543689565298092301062689807689071120317578510142181892798247199071452022029172707400688758980305702923813291544851703914211657597582497807598793035565731652297925769886549168450867091163868402442018371341022143349040941897422377931540131712376088451926646802255265721820332564453961091792448710886674897251899281432897966817352381951694370184383299109654078410356489144960977274480320655205474842571310858767154579079644215514199003832599232631020684528203955813111140473074686810426051322892063650122841004997271652977702547274337834459757112850838135183696311712170990224739928697694772853140476802033735594574707189941820656793611572800671948131128109558012358679446259496244143021997936801273888393102412918463505832701613704464047394891693567824946365095976820092895872874833067345472399549213736568277881574159120670765215962463587184455433922702506813953637742383768964226648365610070168839324749896910992390804658988479107678562550844858514512762455637677863067821690083222834405613388709119188719479181528190836888908152845729021513491658586509889455613570273121541638995145894561079999213500076101248781500642979091198044736325729107144579768273776743716439557581557253878204647391176582851167312182026188795156620056856503340092247479478684738621107994804323593105039052556442336528920420940313
real    0m0.350s
user    0m0.337s
sys    0m0.010s

time cat a.bc | bc
40279005053122345768067055829218304493044109455152896641933464292007\
59023700825508498789380111228748403226643957277673191284838468927263\
98968790560901035018977865543415443376965144616549510538851077440410\
16581978207347558308207939650411138088491681076846747131716891318394\
82758974908036466987938461908525944177396717869145634721620931809562\
84720843607311204509397095907530114810381703803860648328656344389023\
07797564774862888681746680472485858774784093678446243617397742999118\
27532073023480165384946420013014323952797267455381787277085030908707\
45742249581124437084158031806471602854863650302741825130214652788342\
62128387017583390657265689010443241309517109572355085104736018270081\
76664478334500979289573868762717655541374071117476665123099806785398\
86786878262902584539118231519316835523885400137767203426696953126303\
29282822423534913463028008448006465049776475547382410225945312773007\
77775310631151387649525275970984453800464439975409258800869363179334\
21768424925084707414812932329166745886234137226923024813461900363225\
99946452493522794764716794743441163713920351740437121423299823949395\
45623233270769039159314433053699628563882650273461556233325433029434\
46674383336900484885947609695640139797208838438493998636482572950930\
77791964440615462408422804298527057377454368956529809230106268980768\
90711203175785101421818927982471990714520220291727074006887589803057\
02923813291544851703914211657597582497807598793035565731652297925769\
88654916845086709116386840244201837134102214334904094189742237793154\
01317123760884519266468022552657218203325644539610917924487108866748\
97251899281432897966817352381951694370184383299109654078410356489144\
96097727448032065520547484257131085876715457907964421551419900383259\
92326310206845282039558131111404730746868104260513228920636501228410\
04997271652977702547274337834459757112850838135183696311712170990224\
73992869769477285314047680203373559457470718994182065679361157280067\
19481311281095580123586794462594962441430219979368012738883931024129\
18463505832701613704464047394891693567824946365095976820092895872874\
83306734547239954921373656827788157415912067076521596246358718445543\
39227025068139536377423837689642266483656100701688393247498969109923\
90804658988479107678562550844858514512762455637677863067821690083222\
83440561338870911918871947918152819083688890815284572902151349165858\
65098894556135702731215416389951458945610799992135000761012487815006\
42979091198044736325729107144579768273776743716439557581557253878204\
64739117658285116731218202618879515662005685650334009224747947868473\
8621107994804323593105039052556442336528920420940313
real    0m4.785s
user    0m4.770s
sys    0m0.007s

不行了 bc跟不上了非常大的时候python的优势体现出来了

/************************************************************************/

改成5000! 哦 py不行了。。。

太长了具体结果不贴了。。

time ./a.py
real    0m50.277s
user    0m49.937s
sys    0m0.010s

昨天晚上回去用C写了一个在这个时候C的优势体现出来了

time ./c.out
real    0m0.404s
user    0m0.303s
sys    0m0.000s

如果再大 C也不行了那就得用快速傅里叶变换了罢

[ 本帖最后由 zklhp 于 2013-3-26 08:51 编辑 ]

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