Czynniki i niekończące się cykle!


33

Jak zapewne wiesz, silnia dodatniej liczby całkowitej njest iloczynem wszystkich liczb całkowitych dodatnich, które są równe lub mniejsze od n.

Na przykład :

6! = 6*5*4*3*2*1 = 720
0! = 1

Zdefiniujemy teraz specjalną operację o nieistotnej nazwie, taką jak sumFac:

Biorąc pod uwagę dodatnią liczbę całkowitą n, sumFac(n)jest sumą silni cyfr.

Na przykład :

sumFac(132) = 1! + 3! + 2! = 9

Zadanie

Twoja misja, niezależnie od tego, czy zdecydujesz się ją zaakceptować, polega na zwróceniu sekwencji (potencjalnie nieskończonej) aplikacji sumFacna liczbę całkowitą podaną na wejściu.

Przykład: 132 -> 132, 9, 362880, 81369, 403927, ...

Ale to nie wszystko! Rzeczywiście, aplikacje sumFacostatecznie stworzą cykl. Musisz także zwrócić ten cykl!

Jeśli twój język ma wbudowaną silnię, możesz jej użyć. Nie jestem wybredny co do typu zwrotu, wystarczy zwrócić sekwencję aplikacji sumFac i cykl w formacie zrozumiałym dla człowieka.

EDYCJA: Aby pomóc ci lepiej wyobrazić sobie, jak powinien wyglądać wynik, skopiowałem Leaky Nun tuż poniżej:

[132, 9, 362880, 81369, 403927, 367953, 368772, 51128, 40444, 97, 367920, 368649, 404670, 5810, 40442, 75, 5160, 842, 40346, 775, 10200, 6, 720, 5043, 151, 122, 5, 120, 4, 24, 26, 722, 5044, 169, 363601, 1454]

Musisz tylko zatrzymać sekwencję, gdy cykl ma się rozpocząć po raz drugi!

Ale to jest golf golfowy, więc wygrywa najkrótsza odpowiedź w bajtach!

Tabela liderów

Oto fragment kodu, który pozwala wygenerować zarówno zwykłą tabelę wyników, jak i przegląd zwycięzców według języka.



Witamy w PPCG! To wygląda na niezłe wyzwanie, BTW.
clismique

@ Qwerp-Derp Dziękuję bardzo! Próbowałem być kreatywny ^^

@Zgarb Cóż, to dokładnie tak, jak wyjście Leaky Nun. Sekwencja aplikacji, a następnie kończy się tuż przed rozpoczęciem drugiego cyklu. Skopiuję jego wyniki w pytaniu, aby każdy mógł mieć jasne zrozumienie. Dziękujemy za zwrócenie uwagi :)

1
@ 2501

Odpowiedzi:


19

Galaretka , 6 bajtów

D!SµÐĿ
    ÐĿ  Repeat until the results are no longer unique. Collects all intermediate results.
D           Convert from integer to decimal (list of digits)
 !          Factorial (each digit)
  S         Sum

Wypróbuj online!

Nie widzę innego sposobu skrócenia tego niż zrobienie tego, co powiedziano.

Okular

  • Dane wejściowe: 132(jako argument wiersza poleceń)
  • Wydajność: [132, 9, 362880, 81369, 403927, 367953, 368772, 51128, 40444, 97, 367920, 368649, 404670, 5810, 40442, 75, 5160, 842, 40346, 775, 10200, 6, 720, 5043, 151, 122, 5, 120, 4, 24, 26, 722, 5044, 169, 363601, 1454]

Nie spodziewałem się, że odpowiedź będzie tak krótka. Fajnie :)

4
@Antoine It's Jelly: D Zawsze jest krótszy niż myślę, że będzie;)
HyperNeutrino

8
@HyperNeutrino Jakoś Dennis przyjdzie z jeszcze krótszą odpowiedzią
Leaky Nun

Jakoś tak. Ponieważ Dennis. : P
HyperNeutrino

Więc ... Jakiego kodowania znaków używasz, aby uzyskać 6 bajtów dla tych 6 znaków? Czy Jelly nie powinien być kodowany w UTF-8, co oznacza, że ​​ten program ma w rzeczywistości 9 bajtów?
LordOfThePigs

10

Python 2 , 88 bajtów

import math
f=lambda x,l=[]:l*(x in l)or f(sum(math.factorial(int(i))for i in`x`),l+[x])

Wypróbuj online!


Jako fan Pythona cieszę się, że ktoś na to odpowiedział, miło :)

9

05AB1E , 12 bajtów

[DˆS!O©¯så#®

Wypróbuj online!

Wyjaśnienie

[               # infinite loop
 Dˆ             # add a copy of current value to the global list (initialized as input)
   S            # split current number to digits
    !O          # calculate factorial of each and sum
      ©         # save a copy in register
       ¯så#     # if the current number is in the global list, exit loop
           ®    # retrieve the value from the register for the next iteration
                # implicitly output the global list

Krótkie i poprawne, dobrze zagrane!

Myślałem, że mogę się tego pozbyć s, myliłem się, miła odpowiedź.
Magic Octopus Urn

8

Brachylog , 17 bajtów

g:I{tẹḟᵐ+}ᵃ⁾L¬≠Lk

Wypróbuj online!

Wyjaśnienie

g:I{     }ᵃ⁾         Accumulate I (a variable) times, with [Input] as initial input:
    t                  Take the last integer
     ẹḟᵐ+              Compute the sum of the factorial of its digits
            L        The result of the accumulation is L
            L­      Not all elements of L are different
               Lk    Output is L minus the last one (which is the start of the loop)

Co Iznaczy
Leaky Nun

1
@LeakyNun Jest to parametr do ᵃ⁾. ᵃ³oznacza „kumuluj 3 razy”. ᵃ⁾oznacza „kumuluj tyle razy, ile ostatni element wejścia”, co w tym przypadku jest I. Ponieważ Ijest to całkowicie darmowa zmienna, wypróbuje dla niej wartości od 0do +inf.
Fatalize

8

Język Wolfram, 62 60 56 bajtów

Most@NestWhileList[Tr[IntegerDigits@#!]&,#,UnsameQ,All]&

Naprawdę szkoda, że ​​język Wolfram ma tak okropnie długie nazwy funkcji. *Westchnienie*

Wyjaśnienie:

Most[NestWhileList[Tr[IntegerDigits[#]!]&,#,UnsameQ,All]]&
                      IntegerDigits[#]                     (*Split input into list of digits*)
                                      !                    (*Factorial each element in the list*)
                   Tr[                 ]&                  (*Sum the list together*)
     NestWhileList[                      ,#,UnsameQ,All]   (*Iterate the function over itself, pushing each to a list, until a repeat is detected*)
Most[                                                   ]& (*Remove the last element in the list*)

Niezła odpowiedź. Nie sądzę, że można to poprawić.
Kelly Lowder

1
@KellyLowder Thanks! Byłem w stanie zaoszczędzić jeszcze dwa bajty, mapując silnię na listę, a następnie sumując ją Tr.
Scott Milner,

1
Niezłe wykorzystanie NestWhileList[...,All]!
Greg Martin

6

JavaScript (ES6), 91 89 bajtów

Zaoszczędzono 2 bajty dzięki fəˈnɛtɪk

It turns out to be quite similar to the other JS answer.

f=(n,x=!(a=[n]))=>n?f(n/10|0,x+(F=n=>n?n--*F(n):1)(n%10)):~a.indexOf(x)?a:f(x,!a.push(x))


In your factorial function shouldn't you be able to use n instead of n>1 because 0!=1?
fəˈnɛtɪk

@fəˈnɛtɪk I don't know what I was thinking here. Thank you!
Arnauld

5

ClojureScript, 146 109 bytes

#(loop[n[%]](let[f(apply +(for[a(str(last n))](apply *(range 1(int a))))](if(some #{f}n)n(recur(conj n f)))))

Yikes, that is a monstrosity. Someone please help me golf this...

Thanks @cliffroot for shaving off a whopping 37 bytes!

This is an anonymous function, to run the function, you have to do this:

(#(...) {arguments})

TIO doesn't have ClojureScript, so here's a link to a ClojureScript REPL.

Here's a link to a Clojure program which prints the last element in the list from 0 to 1000.

Here's the output for 9999:

[9999 1451520 269 363602 1455 265 842 40346 775 10200 6 720 5043 151 122 5 120 4 24 26 722 5044 169 363601 1454]

I have a strong suspicion that all numbers must eventually settle at 1 or the loop [169 363601 1454].

Ungolfed code:

(defn fact-cycle [n]
  (loop [nums [n]]
    (let [fact-num
          (let [str-n (str (last nums))]
            (apply +
              (for [a (range (count str-n))]
                (apply *
                  (range 1
                    (inc (int (nth str-n a))))))))]
      (if (some #{fact-num} nums) nums
        (recur
          (conj nums fact-num))))))

Explanation coming soon!


Quite long but correct ;) I cannot really help you to golf this sorry ^^

the inner for can be (for[a s](apply *(range 1(-(int a)47)))), can't it?
cliffroot

and this will allow to get rid of the other let #(loop[n[%]](let[f(apply +(for[a(str(last n))](apply *(range 1(-(int a)47)))))](if(some #{f}n)n(recur(conj n f)))))
cliffroot

oh, seems you don't even need (- ... 47) in ClojureScript, just int will suffice
cliffroot

well, (inc(int a)) should do for ClojureScript and (-(int a)47) for Clojure.
cliffroot

5

Perl 6, 64 bytes

{my@a;$_,{[+] .comb.map:{[*] 2..$_}}...^{$_@a||!@a.push: $_}}

Try it

Expanded:

{

  my @a;             # array of values already seen

  $_,                # seed sequence with the input

  {
    [+]              # reduce using &infix:<+>
      .comb          # the digits of $_ (implicit method call)
      .map:          # do the following for each
      {
        [*] 2..$_    # get the factorial of
      }
  }


  ...^               # keep generating values until
                     # (「^」 means throw away the last value when done)

  {
      $_  @a        # is it an elem of @a? (「∈」 is shorter than 「(cont)」)

    ||               # if it's not

      !              # boolean invert so this returns False
        @a.push: $_  # add the tested value to @a
  }
}

Every line above that has { starts a new bare block lambda with an implicit parameter of $_.

I used [*] 2..$_ instead of [*] 1..$_ purely as a micro optimization.


4

JavaScript, 92 bytes

Thanks @Shaggy for golfing off one byte with includes
Thanks @Neil for golfing off two bytes

Code separated into individual functions 92 bytes

f=(x,a=[])=>a.includes(x)?a:f(k(x),a,a.push(x))
p=y=>y?y*p(y-1):1
k=n=>n?p(n%10)+k(n/10|0):0

Code on one line 92 bytes

f=(x,a=[])=>a.includes(x)?a:f((k=n=>n?(p=y=>y?y*p(y-1):1)(n%10)+k(n/10|0):0)(x),a,a.push(x))

Explanation

Initially call the function with just a single argument, therefore a=[].

If x exists in the array a return a a.includes(x)?a:...

Otherwise, append x to a and pass the factorial digit sum and a to the function (a.push(x),f(k(x),a))

p=y=>y?y*p(y-1):1
k=n=>n?p(n%10)+k(n/10|0):0

Factorial Digit sum performed so that it will not exceed the maximum recursion limit.

List of all possible endpoints: 1, 2, 145, 169, 871, 872, 1454, 40585, 45361, 45362, 363601

Try it online!


1
Gah, I was so close! Save a byte with f=(x,a=[])=>a.includes(x)?a:(a.push(x),f(k(x),a))
Shaggy

Can you not write f(k(x),a,a.push(x))? Also, I think you can write k=n=>n&& to save another byte.
Neil

4

Haskell, 80 67 bytes

g#n|elem n g=g|h<-g++[n]=h#sum[product[1..read[d]]|d<-show n]
([]#)

Try it online! Usage: ([]#) 132

Edit: Saved 13 bytes with typs from Ørjan Johansen!


(1) Test and append n instead of s(same as in ovs's Python answer), then f=([]#). (2) Switch the branches, inline s, and use elem.
Ørjan Johansen

Switch out your ++ for : also.

1
@Canyon It's the wrong order around for that, it would give the final result reversed. You can almost fix it up afterwards, by prepending an extra n: and changing =g to =[], but it seems to be only a tie.
Ørjan Johansen

4

Pyth, 9 bytes

.us.!MjNT
.us.!MjNTQ  implicit Q

.u          explained below
       N      current value
      j T     convert to decimal (list of digits)
   .!M        factorial of each digit
  s           sum

Try it online!

This answer uses .u ("Cumulative fixed-point. Apply until a result that has occurred before is found. Return all intermediate results.")




2

R, 120 Bytes

o=scan()
repeat {
q=sum(factorial(as.double(el(strsplit(as.character(o[length(o)]), "")))))
if(q%in%o)break
o=c(o,q)
}
o

you can do o=scan(), use el() instead of [[1]], and gamma(n+1)=factorial(n) which I believe saves a byte, and I think as.numeric is the same as as.double for integers, which also saves a byte, and you can use toString instead of as.character.
Giuseppe

@Giuseppe Thanks for the input, updated.
Neil

2

Java 9 JSHell, 213 bytes

n->{Set<Integer>s=new HashSet<>();
return IntStream.iterate(n,i->(""+i).chars()
.map(x->x<50?1:IntStream.rangeClosed(2,x-48)
.reduce(1,(a,b)->a*b)).sum()).boxed()
.takeWhile(x->s.add(x)).collect(Collectors.toList());}

Try it online!

Note: This solution relies on the string representation of a number having code points in the range 48-57. Works for ASCII, UTF-8, Latin-1, all ISO-8859-* character sets, most code pages. Does not work for EBCDIC. I don't think anyone will deduct points for that. :)

Ungolfed:

Function<Integer, List<Integer>> f =        // function from Integer to List of Integer
n -> {
    Set<Integer> s = new HashSet<>();       // memo of values we've seen
    return IntStream.iterate(n,             // iterate over n, f(n), f(f(n)), etc.
    i -> (""+i).chars()                     // the sumFac function; for all chars
        .map(x -> x < 50? 1 :               // give 1 for 0! or 1!
        IntStream.rangeClosed(2, x-48)      // else produce range 2..d 
        .reduce(1,(a,b)->a*b))              // reduction to get the factorial
        .sum())                             // and sum up the factorii!

                                            // now we have a stream of ints
                                            // from applying sumFac repeatedly
        .boxed()                            // box them into Integers (thanks, Java)
        .takeWhile(x->s.add(x))             // and take them while not in the memo
        .collect(Collectors.toList());      // collect them into a list
}

Notes:

  • The return value of Set::add is very helpful here; returns true iff the item was not in the set
  • I was being sarcastic when I said "Thanks, Java"
  • factorii isn't really a word; I just made that up

1
I admit this is original ! Nice job :)

@Antoine I admit, Java isn't the best language to golf in, but it's hardly the craziest thing I've done lately. :) codegolf.stackexchange.com/a/117644/794
David Conrad

2

Pyth, 22 11 bytes

.usm.!sd+Nk

Try it online!

Lots of credit to Leaky Nun's answer, which introduced me to .u, and helped save a massive 11 bytes of this program.

Explanation:

.usm.!sd+NkQ | ending Q is implicitly added
             | Implicit: Q = eval(input())
.u         Q | Repeat the function with initial value Q until a previous value is found. Return all intermediate values
  s          | Summation
   m.!sd     | For each character 'd' in the string, convert to integer and take the factorial
        +Nk  | Convert function argument to string

Pyth has more useful functions than one imagines. See my answer as reference.
Leaky Nun

@LeakyNun I've rewritten my answer to use .u. I guess I'll need to take a look through the character reference again to see if there are any other useful functions there.
K Zhang

You can use `N to convert to string instead of +Nk.
Leaky Nun

@LeakyNun Where the N would be obsolete then, and there comes a 9-byte solution...
Erik the Outgolfer

1

Axiom, 231 bytes

l(a:NNI):List NNI==(r:List NNI:=[];repeat(r:=cons(a rem 10,r);a:=a quo 10;a=0=>break);r)
g(a:NNI):NNI==reduce(+,[factorial(x) for x in l(a)])
h(a:NNI):List NNI==(r:=[a];repeat(a:=g(a);member?(a,r)=>break;r:=cons(a,r));reverse(r))

not golfed functions and some test

-- convert one NNI in its list of digits
listify(a:NNI):List NNI==
    r:List NNI:=[]
    repeat
        r:=cons(a rem 10,r)
        a:=     a quo 10
        a=0=>break
    r

-- g(1234)=1!+2!+3!+4!
SumfactorialDigits(a:NNI):NNI==reduce(+,[factorial(x) for x in listify(a)])

ListGenerateFromSumFactorialDigits(a:NNI):List NNI==
    r:=[a]
    repeat
       a:=SumfactorialDigits(a)
       member?(a,r)=>break
       r:=cons(a,r)
    reverse(r)

(9) -> h 132
   (9)
   [132, 9, 362880, 81369, 403927, 367953, 368772, 51128, 40444, 97, 367920,
    368649, 404670, 5810, 40442, 75, 5160, 842, 40346, 775, 10200, 6, 720,
    5043, 151, 122, 5, 120, 4, 24, 26, 722, 5044, 169, 363601, 1454]

1

Java 7, 220 bytes

String c(int n){String r=n+",",c;for(;!r.matches("^"+(c=(n=d(n))+",")+".*|.*,"+c+".*");r+=c);return r;}int d(int n){int s=0;for(String i:(n+"").split(""))s+=f(new Long(i));return s;}long f(long x){return x<2?1:x*f(x-1);}

Explanation:

String c(int n){                            // Method with integer parameter and String return-type
  String r=n+",",                           //  Result-String (which starts with the input integer + a comma
         c;                                 //  Temp String
  for(;!r.matches(                          //  Loop as long as the result-String doesn't match the following regex:
    "^"+(c=(n=d(n))+",")+".*|.*,"+c+".*");  //    "^i,.*|.*,i,.*" where `i` is the current integer
                                            //   `n=d(n)` calculates the next integer in line
                                            //   `c=(n=d(n))+","` sets the temp String to this integer + a comma
    r+=c                                    //   And append the result-String with this temp String
  );                                        //  End of loop
  return r;                                 //  Return the result-String
}                                           // End of method

int d(int n){                               // Separate method (1) with integer parameter and integer return-type
  int s=0;                                  //  Sum
  for(String i:(n+"").split(""))            //  Loop over the digits of `n`
    s+=f(new Long(i));                      //   And add the factorial of these digits to the sum
                                            //  End of loop (implicit / single-line body)
  return s;                                 //  Return the sum
}                                           // End of separate method (1)

long f(long x){                             // Separate method (2) with long parameter and long return-type (calculates the factorial)
                                            // (NOTE: 2x `long` and the `new Long(i)` is shorter than 2x `int` and `new Integer(i)`, hence long instead of int)
  return x<2?                               //  If `x` is 1:
      1                                     //   return 1
    :                                       //  Else:
      x*f(x-1);                             //   return `x` multiplied by the recursive-call of `x-1`
}                                           // End of method (2)

Test code:

Try it here.

class M{
  String c(int n){String r=n+",",c;for(;!r.matches("^"+(c=(n=d(n))+",")+".*|.*,"+c+".*");r+=c);return r;}int d(int n){int s=0;for(String i:(n+"").split(""))s+=f(new Long(i));return s;}long f(long x){return x<2?1:x*f(x-1);}

  public static void main(String[] a){
    System.out.println(new M().c(132));
  }
}

Output:

132,9,362880,81369,403927,367953,368772,51128,40444,97,367920,368649,404670,5810,40442,75,5160,842,40346,775,10200,6,720,5043,151,122,5,120,4,24,26,722,5044,169,363601,1454,

1

GolfScript, 44 bytes

~]{..)\;10base{,1\{)*}/}%{+}*.@\+@@?)!}do);`

~                                             eval input
 ]                                            initialization
  {                                   }do     do...
   ..)\;                                          initialization
        10base                                    get digits
              {,1\{)*}/}%                         factorial each
                         {+}*                     sum
                             .@\+@@?)!        while result not found
                                         );   drop last element
                                           `  tostring

Try it online!

The factorial part is from here.


1

C, 161 bytes

f(a){return a?a*f(a-1):1;}
a(l){return l?f(l%10)+a(l/10):0;}
c,t,o;r(i){for(t=o=i;t=a(t),o=a(a(o)),c=t^o;);for(t=i;t^c;printf("%d ",t),c=c|t^o?c:o,t=a(t),o=a(o));}

See it work online.


1

TI-BASIC, 85 79 64 60 bytes

:Prompt L₁                             //Get input as 1 length list, 4 bytes
:Lbl C                                //create marker for looping, see below, 3 bytes
:int(10fPart(Xseq(10^(~A-1),A,0,log(X //split input into list of digits, 20 bytes
:sum(Ans!→X                           //factorial and sum the list, write to new input, 6 bytes
:If prod(L₁-X                         //Test to see if new element is repeated, see below, 7 bytes
:Then                                 //Part of If statement, 2 bytes
:augment(L₁,{X→L₁                     //Push new input to List 1, 10 bytes
:Goto C                               //Loop back to beginning, 3 bytes
:Else                                 //Part of If statement, 2 bytes
:L₁                                   //Print Answer, 2 bytes

Since this is running on a graphing calculator, there is limited RAM. Try testing it with numbers that loop quickly, like 169.

More Explanation:

:int(10fPart(Xseq(10^(~A-1),A,0,log(X
              seq(10^(~A-1),A,0,log(X //Get a list of powers of 10 for each digit (i.e. 1, 0.1, 0.01, etc.)
             X                        //Multiply by input
       fPart(                         //Remove everything but the decimal
     10                               //Multiply by 10 (move one digit in front of the decimal
:int(                                 //Truncate to an integer

If prod(L₁-X works by subtracting the new element from the old list, then multiplying all the elements of the list together. If the element was already in the list, the product will be 0, a falsey value. Otherwise, the product will be a positive integer, a truthy value.



1

J, 40 31 bytes

Edit: 9 bytes saved using the improvements by FrownyFrog. Thanks!

f=.$:@,~`]@.e.~[:+/@:!10#.inv{:

Original code:

f=.[`($:@,)@.([:-.e.~)[:+/!@("."0&":@{:)

In this case I decided to count the bytes for the verb definition, since otherwise it doesn't work in the interpreter.

Explanation:

                         (        {:) - Takes the last element of the array
                               ":@    - converts it to string
                          "."0&       - converts each character back to integer
                       !@             - finds the factorials
                     +/               - sums them
                   [:                 - cap (there are 2 derived verbs above, we need 3 for a fork)
          (    e.~)                   - check if the result is present in the list    
             -.                       - negates the above check
           [:                         - cap
        @.                            - Agenda conjunction, needed for the recursion
  ($:@,)                              - if the result is not in the list, add it to the list and recur
[`                                    - if the result is in the list, display it and stop    

Try it online!


1
([:-.e.~) -> (1-e.~)
FrownyFrog


@FrownyFrog Thanks, your code is much better! I tried 10#.inv early while experimenting, but then I wrote it 10&#.inv and it was longer, so I rejected it. Thanks for all your suggestions! I have much to learn :)
Galen Ivanov

@FrownyFrog Reversing the cases for the agenda is so good, I regret I didn't see it :)
Galen Ivanov

[:+/!@"."0@":@{: is the same length, so there's no improvement with 10#.inv. Just had to drop the ().
FrownyFrog

1

Tcl, 143 bytes

proc P {n L\ ""} {proc F n {expr $n?($n)*\[F $n-1]:1}
while {[set n [expr [join [lmap d [split $n ""] {F $d}] +]]] ni $L} {lappend L $n}
set L}

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