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display output larger than 65536
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itoney...@gmail.com
Dec 16, 2014, 4:34:23 PM12/16/14
to
I can't get rice to display larger than 65,536. See:
vector <int> squares;
int main()
{
signed long long int rice = 1;
for (int i = 0; i < 15; ++i)
{
squares.push_back(rice);
cout << squares[i] << endl;
if (rice == 1)
rice = 2;
else
rice = rice * rice;
}
}
vector <int> squares;
int main()
{
signed long long int rice = 1;
for (int i = 0; i < 15; ++i)
{
squares.push_back(rice);
cout << squares[i] << endl;
if (rice == 1)
rice = 2;
else
rice = rice * rice;
}
}
Mark Blair
Dec 16, 2014, 4:40:04 PM12/16/14
to
On 12/16/2014 3:34 PM, itoney...@gmail.com wrote:
> I can't get rice to display larger than 65,536. See:
>
> vector <int> squares;
Should be:
> I can't get rice to display larger than 65,536. See:
>
> vector <int> squares;
vector <long long int> squares;
mathewji
Dec 16, 2014, 4:58:06 PM12/16/14
to
Made the change. I can't get rice to display larger than 4,294,967,296. See:
vector <signed long long int> squares;
vector <signed long long int> squares;
Victor Bazarov
Dec 16, 2014, 5:07:09 PM12/16/14
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number in a 'long long'. Are you surprised? Why? It requires more
than 64 bits, which is what your 'long long' has, probably.
Use Google to search for "arbitrary precision integer" and use some
library, there are probably open source ones out there.
V
--
I do not respond to top-posted replies, please don't ask
Barry Schwarz
Dec 16, 2014, 5:39:57 PM12/16/14
to
On Tue, 16 Dec 2014 13:34:13 -0800 (PST), itoney...@gmail.com
wrote:
Changing squares to vector<long long> will postpone the error but not
solve the problem. To see why, take a piece of paper and write down
the value of rice for the first few values of i. (Hint: make life
easy on yourself and write the values as powers of 2.) How soon will
rice exceed the value of LLONG_MAX?
--
Remove del for email
wrote:
solve the problem. To see why, take a piece of paper and write down
the value of rice for the first few values of i. (Hint: make life
easy on yourself and write the values as powers of 2.) How soon will
rice exceed the value of LLONG_MAX?
--
Remove del for email
Öö Tiib
Dec 16, 2014, 6:47:52 PM12/16/14
to
to 9223372036854775807 (beaten at 8th iteration) you will also run out
of limits of 'double' at 12th iteration (despite C++ does not specify
it). So there you are.
C++ does not contain any arbitrary precision numeric types but you can
search web for "arbitrary precision C++". You will find several open
source implementations of various quality. Most can deal with
multiplying values that have millions of numbers.
Öö Tiib
Dec 16, 2014, 6:59:31 PM12/16/14
to
On Wednesday, 17 December 2014 01:47:52 UTC+2, Öö Tiib wrote:
> C++ does not contain any arbitrary precision numeric types but you can
> search web for "arbitrary precision C++". You will find several open
> source implementations of various quality. Most can deal with
> multiplying values that have millions of numbers.
Meant "millions of digits". Digit is "number" in Estonian so I mix
> C++ does not contain any arbitrary precision numeric types but you can
> search web for "arbitrary precision C++". You will find several open
> source implementations of various quality. Most can deal with
> multiplying values that have millions of numbers.
the words up now and then.
David Harmon
Dec 16, 2014, 7:59:53 PM12/16/14
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On Tue, 16 Dec 2014 13:57:56 -0800 (PST) in comp.lang.c++, mathewji
<itoney...@gmail.com> wrote,
How many bits long would a integer variable have to be
to hold your final answer?
<itoney...@gmail.com> wrote,
>Made the change. I can't get rice to display larger than 4,294,967,296. See:
>vector <signed long long int> squares;
And what is the lesson you have learned from all this?
>vector <signed long long int> squares;
How many bits long would a integer variable have to be
to hold your final answer?
Nobody
Dec 17, 2014, 12:38:35 AM12/17/14
to
On Tue, 16 Dec 2014 17:06:59 -0500, Victor Bazarov wrote:
> Use Google to search for "arbitrary precision integer" and use some
> library, there are probably open source ones out there.
Boost.Multiprecision:
> Use Google to search for "arbitrary precision integer" and use some
> library, there are probably open source ones out there.
http://www.boost.org/doc/libs/1_57_0/libs/multiprecision/doc/html/index.html
Jorgen Grahn
Dec 17, 2014, 1:59:54 AM12/17/14
to
On Tue, 2014-12-16, 嘱 Tiib wrote:
I still mix them up ...
/Jorgen
--
// Jorgen Grahn <grahn@ Oo o. . .
\X/ snipabacken.se> O o .
> On Wednesday, 17 December 2014 01:47:52 UTC+2, 嘱 Tiib wrote:
>> C++ does not contain any arbitrary precision numeric types but you can
>> search web for "arbitrary precision C++". You will find several open
>> source implementations of various quality. Most can deal with
>> multiplying values that have millions of numbers.
>
> Meant "millions of digits". Digit is "number" in Estonian so I mix
> the words up now and then.
We have distinct words for them in Sweden ("tal", "siffra"), but
>> C++ does not contain any arbitrary precision numeric types but you can
>> search web for "arbitrary precision C++". You will find several open
>> source implementations of various quality. Most can deal with
>> multiplying values that have millions of numbers.
>
> Meant "millions of digits". Digit is "number" in Estonian so I mix
> the words up now and then.
I still mix them up ...
/Jorgen
--
// Jorgen Grahn <grahn@ Oo o. . .
\X/ snipabacken.se> O o .
Paul N
Dec 17, 2014, 10:15:39 AM12/17/14
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Victor Bazarov
Dec 17, 2014, 10:49:56 AM12/17/14
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of [rice] kernels was doubled every iteration, not squared, yes?
red floyd
Dec 17, 2014, 12:46:46 PM12/17/14
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You only go up to 2**15. Why would you expect to see anything else?
Victor Bazarov
Dec 17, 2014, 1:27:57 PM12/17/14
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Scott Lurndal
Dec 17, 2014, 2:17:51 PM12/17/14
to
lose precision.
Problem #2: 2^16 squared is 2^32, which won't fit in a signed "int", so
problem #1 bites such that squares[6] gets zero instead of 2^32.
Problem #3: 2^32 squared is larger than a 'signed long long int' and thus
overflow occurs on the 8th loop iteration.
Problem #4: The problem statement likely requested the squares of the first
16 positive integers, in which case "push_back((i+1)*(i+1)" was probably the
intended code and the rice variable is unnecessary.
Jorgen Grahn
Dec 17, 2014, 3:59:16 PM12/17/14
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Vincenzo Mercuri
Dec 17, 2014, 4:44:50 PM12/17/14
to
for multiprecision integers:
#include <iostream>
#include <vector>
#include <boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
std::vector<cpp_int> squares;
int main()
{
cpp_int rice = 1;
for(int i = 0; i < 15; ++i)
{
squares.push_back(rice);
std::cout << squares[i] << std::endl;
if(rice == 1)
rice = 2;
else
rice *= rice;
}
}
(sorry, I didn't wrap the output lines on purpose)
$./main
1
2
4
16
256
65536
4294967296
18446744073709551616
340282366920938463463374607431768211456
115792089237316195423570985008687907853269984665640564039457584007913129639936
13407807929942597099574024998205846127479365820592393377723561443721764030073546976801874298166903427690031858186486050853753882811946569946433649006084096
179769313486231590772930519078902473361797697894230657273430081157732675805500963132708477322407536021120113879871393357658789768814416622492847430639474124377767893424865485276302219601246094119453082952085005768838150682342462881473913110540827237163350510684586298239947245938479716304835356329624224137216
32317006071311007300714876688669951960444102669715484032130345427524655138867890893197201411522913463688717960921898019494119559150490921095088152386448283120630877367300996091750197750389652106796057638384067568276792218642619756161838094338476170470581645852036305042887575891541065808607552399123930385521914333389668342420684974786564569494856176035326322058077805659331026192708460314150258592864177116725943603718461857357598351152301645904403697613233287231227125684710820209725157101726931323469678542580656697935045997268352998638215525166389437335543602135433229604645318478604952148193555853611059596230656
1044388881413152506691752710716624382579964249047383780384233483283953907971557456848826811934997558340890106714439262837987573438185793607263236087851365277945956976543709998340361590134383718314428070011855946226376318839397712745672334684344586617496807908705803704071284048740118609114467977783598029006686938976881787785946905630190260940599579453432823469303026696443059025015972399867714215541693835559885291486318237914434496734087811872639496475100189041349008417061675093668333850551032972088269550769983616369411933015213796825837188091833656751221318492846368125550225998300412344784862595674492194617023806505913245610825731835380087608622102834270197698202313169017678006675195485079921636419370285375124784014907159135459982790513399611551794271106831134090584272884279791554849782954323534517065223269061394905987693002122963395687782878948440616007412945674919823050571642377154816321380631045902916136926708342856440730447899971901781465763473223850267253059899795996090799469201
774624817718449867455659250178329070473119433165550807568221846571746373296884912819520317457002440926616910874148385078411929804522981857338977648103126085903001302413467189726673216491511131602920781738033436090243804708340403154190336
1090748135619415929462984244733782862448264161996232692431832786189721331849119295216264234525201987223957291796157025273109870820177184063610979765077554799078906298842192989538609825228048205159696851613591638196771886542609324560121290553901886301017900252535799917200010079600026535836800905297805880952350501630195475653911005312364560014847426035293551245843928918752768696279344088055617515694349945406677825140814900616105920256438504578013326493565836047242407382442812245131517757519164899226365743722432277368075027627883045206501792761700945699168497257879683851737049996900961120515655050115561271491492515342105748966629547032786321505730828430221664970324396138635251626409516168005427623435996308921691446181187406395310665404885739434832877428167407495370993511868756359970390117021823616749458620969857006263612082706715408157066575137281027022310927564910276759160520878304632411049364568754920967322982459184763427383790272448438018526977764941072715611580434690827459339991961
41424274141059911742606055648376375631452761136265862838336862115799363802087853767554533678991569423443395566631507008721353547025567031200413072549583450835743965382893607708097855057891296790735278005493562156109079584517295411597292747987752773856000820411855893000477774872776185381351049384058186159865221160596030835640594182118971403786872621948149872760365361629885617482241303348543878532402475141941718301228107820972930353737280457437209522870362277636394529086980625842235514850757103961938744962986680818876966281577815307939317909314364834076173858181956300299442279075495506128881830843007964869323217915876591803556521615711540299212027615560787310793747746684152836298770869945015203123186259420308569383894465706134623670423402682110295895495119708707654618662279629453645162075650935101890602377382153953277620867697858973196633030889330466516943618507835064156833694453005143749131129883436726523859540490427345592872394952522718461740436785475461047437701976802557660588103807
7270707717942221977090385438585844095492116099852538903974655703943973086090930596963360767529964938414598185705963754561497355827813623833288906309004288017321424808663962671333528009232758350873059614118723781422101460198615747386855096896089189180441339558524822867541113212638793675567650340362970031930023397828465318547238244232028015189689660418822976000815437610652254270163595650875433851147123214227266605403581781469090806576468950587661997186505665475715792896
--
Vincenzo Mercuri
red floyd
Dec 17, 2014, 5:13:45 PM12/17/14
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red floyd
Dec 17, 2014, 5:15:57 PM12/17/14
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