Sfida

Dato un numero intero, , come input dove s ≥ 1 emette il valore di ζ ( s ) (Where ζ ( x $s$$s\geq 1$$\zeta(s)$$\zeta(x)$ rappresenta la funzione Ziem di Riemann ).

Ulteriori informazioni

$\zeta(s)$ è definito come:

Dovresti generare la tua risposta con 5 cifre decimali (niente di più, niente di meno). Se la risposta risulta infinita, dovresti emettere o equivalente nella tua lingua.$\infty$

Gli incorporamenti di Riemann Zeta sono consentiti, ma è meno divertente farlo in questo modo;)

Esempi

Le uscite devono essere esattamente come mostrato di seguito

Input -> Output
1 -> ∞ or inf etc.
2 -> 1.64493
3 -> 1.20206
4 -> 1.08232
8 -> 1.00408
19 -> 1.00000

generosità

Come consolazione per consentire i built-in, offrirò una generosità di 100 rep alla risposta più breve che non lo fa utilizza le funzioni zeta integrate. (Il segno di spunta verde continuerà comunque con la soluzione più breve in assoluto)

vincente

Vince il codice più breve in byte.

Mathematica, 9 7 11 byte

Zeta@#~N~6&

Spiegazione:

Zeta@#       (* Zeta performed on input *)
      ~N     (* Piped into the N function *)
        ~6   (* With 6 digits (5 decimals) *)
          &  (* Make into function *)

Senza incorporato:

Mathematica, 23 byte UTF-8

Sum[1/n^#,{n,∞}]~N~6&

Grazie a Kelly Lowder

Javascript, 81 70 66 65 byte

s=>s-1?new Int8Array(1e6).reduce((a,b,i)=>a+i**-s).toFixed(5):1/0

Esempi eseguibili:

ζ=s=>s-1?new Int8Array(1e6).reduce((a,b,i)=>a+i**-s).toFixed(5):1/0

const values = [ 1, 2, 3, 4, 8, 19 ];
document.write('<pre>');
for(let s of values) {
  document.write('ζ(' + s + ') = ' + ζ(s) + '\n')
}

APL (Dyalog), 22 21 bytes

Look ma, no built-ins! -1 thanks to ngn.

Since Dyalog APL does not have infinities, I use Iverson's proposed notation.

{1=⍵:'¯'⋄5⍕+/÷⍵*⍨⍳!9}

Try it online!

{ anonymous function:

 1=⍵: if the argument is one, then:

  '¯' return a macron

 ⋄ else

  !9 factorial of nine (362880)

  ⍳ first that many integers integers

  ⍵*⍨ raise them to the power of the argument

  ÷ reciprocal values

  +/ sum

  5⍕ format with five decimals

} [end of anonymous function]

C, 74 70 69 bytes

n;f(s){double z=n=0;for(;++n>0;)z+=pow(n,-s);printf("%.5f",z/=s!=1);}

Compile with -fwrapv. It will take some time to produce an output.

See it work here. The part ++n>0 is replaced with ++n<999999, so you don't have to wait. This keeps identical functionality and output.

TI-Basic, 16 bytes (no builtins)

Fix 5:Σ(X^~Ans,X,1,99

C (gcc), 112 101 94 84 bytes

Thanks for the golfing tips from ceilingcat.

n;f(s){float r;for(n=98;n;r+=pow(n--,-s));printf("%.5f",r+pow(99,-s)*(.5+99./--s));}

Try it online!

Julia, 36 bytes

x->x!=1?@sprintf("%.5f",zeta(x)):Inf

MATL, 21 bytes

q?'%.5f'2e5:G_^sYD}YY

Try it online!

Explanation

Input 1 is special-cased to output inf, which is how MATL displays infinity.

For inputs other than 1, summing the first 2e5 terms suffices to achieve a precision of 5 decimal places. The reason is that, from direct computation, this number of terms suffices for input 2, and for greater exponents the tail of the series is smaller.

q         % Input (implicit) minus 1
?         % If non-zero
  '%.5f'  %   Push string: format specifier
  2e5:    %   Push [1 2 ... 2e5]
  G       %   Push input again
  _       %   Negate
  ^       %   Power. element-wise
  s       %   Sum of array
  YD      %   Format string with sprintf
}         % Else
YY        %   Push infinity
          % End (implicit)
          % Display (implicit)

R, 54 bytes

function(a){round(ifelse(a==1,Inf,sum((1:9^6)^-a)),5)}

Finds the sum directly and formats as desired, outputs Inf if a is 1. Summing out to 9^6 appears to be enough to get five-place accuracy while still being testable; 9^9 would get better accuracy in the same length of code. I could get this shorter if R had a proper ternary operator.

C,129 130 128 bytes

#include<math.h>
f(s,n){double r=0;for(n=1;n<999;++n)r+=(n&1?1:-1)*pow(n,-s);s-1?printf("%.5f\n",r/(1-pow(2,1-s))):puts("oo");}

it uses the following formula

test and results

main(){f(2,0);f(1,0);f(3,0);f(4,0);f(8,0);f(19,0);}

1.64493
+oo
1.20206
1.08232
1.00408
1.00000

Python 3: 67 bytes (no built-ins)

f=lambda a:"∞"if a<2else"%.5f"%sum([m**-a for m in range(1,10**6)])

Nothing fancy, only uses python 3 because of the implicit utf-8 encoding.

Try it online with test cases.

Perl 6, 50 bytes

{$_-1??(1..1e6).map(* **-$_).sum.fmt('%.5f')!!∞}

PARI/GP, 27 26 bytes

\p 6
s->trap(,inf,zeta(s))

Jelly, 23 bytes

ȷ6Rİ*⁸S÷Ị¬$ær5;ḷỊ?”0ẋ4¤

Try it online!

How?

• Sums the first million terms
• Divides by 0 when abs(input)<=1 to yield inf (rather than 14.392726722864989) for 1
• Rounds to 5 decimal places
• Appends four zeros if abs(result)<=1 to format the 1.0 as 1.00000
• Prints the result

ȷ6Rİ*⁸S÷Ị¬$ær5;ḷỊ?”0ẋ4¤ - Main link: s
ȷ6                      - literal one million
  R                     - range: [1,2,...,1000000]
   İ                    - inverse (vectorises)
     ⁸                  - link's left argument, s
    *                   - exponentiate
      S                 - sum
          $             - last two links as a monad:
        Ị               -   insignificant? (absolute value of s less than or equal to 1?)
         ¬              -   not (0 when s=1, 1 when s>1)
       ÷                - divide (yielding inf when s=1, no effect when s>1)
           ær5          - round to 10^-5
                      ¤ - nilad followed by link(s) as a nilad:
                  ”0    -   literal '0'
                    ẋ4  -   repeated four times
                Ị?      - if insignificant (absolute value less than or equal to 1?)
              ;         -       concatenate the "0000" (which displays as "1.00000")
               ḷ        - else: left argument
                        - implicit print

Python 3 + SciPy, 52 bytes

lambda n:'%.5f'%zeta(n,1)
from scipy.special import*

Try it online!

Jelly, 26 bytes

⁵*5İH+µŒṘḣ7
⁴!Rİ*³Sǵ’ݵ’?

Don't try it online with this link! (Since this uses 16!~20 trillion terms, running on TIO produces a MemoryError)

Try it online with this link instead. (Uses 1 million terms instead. Much more manageable but takes one more byte)

Returns inf for input 1.

Explanation

⁵*5İH+µŒṘḣ7    - format the output number
⁵*5İH+         - add 0.000005
      µŒṘ      - get a string representation
         ḣ7    - trim after the fifth decimal.

⁴!Rİ*³Sǵ’ݵ’? - main link, input s
           µ’? - if input minus 1 is not 0...
⁴!R            -   [1,2,3,...,16!] provides enough terms.
   İ           -   take the inverse of each term
    *³         -   raise each term to the power of s
      S        -   sum all terms
       Ç       -   format with the above link
               - else:
        µ’İ    -   return the reciprocal of the input minus 1 (evaluates to inf)

Out of the 26, bytes, 7 are used for computation, 12 are for formatting, and 7 are for producing inf on zero. There has to be a better golf for this.

MathGolf, 14 bytes (no builtins)

┴¿Å'∞{◄╒▬∩Σ░7<

Note that in the TIO link, I have substituted ◄ for ►, which pushed $10^6$ instead of $10^7$. This is because the version submitted here timeouts for all test cases. This results in the answers for 3 and 8 to be off by 1 decimal place. However, there are way bigger 1-byte numerical literals in MathGolf, allowing for arbitrary decimal precision.

Try it online!

Explanation

┴                check if equal to 1
 ¿               if/else (uses one of the next two characters/blocks in the code)
  Å              start block of length 2
   '∞            push single character "∞"
     {           start block or arbitrary length
      ◄          push 10000000
       ╒         range(1,n+1)
        ▬        pop a, b : push(b**a)
         ∩       pop a : push 1/a (implicit map)
          Σ      sum(list), digit sum(int)
           ░     convert to string (implicit map)
            7    push 7
             <   pop(a, b), push(a<b), slicing for lists/strings

JavaScript (Node.js), 64 bytes

s=>[...Array(1e6)].reduce((a,b,i)=>s>1>i?a:i**-s+a,0).toFixed(5)

Try it online!

Pointed in Frxstrem's