43
votes
Round towards zero
Python 3, 3 bytes
int
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Truncates the digits after the decimal point.
NOTE: This is a trivial answer. Please take a look at the other answers ...
- 2,722
30
votes
Egyptian fraction representations of 1
Python 2, 42 bytes
f=lambda n,x=1:1/n*[x]or[x+1]+f(n-1,x*-~x)
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The key thing to observe is that ...
- 22.8k
23
votes
22
votes
Half, Half Half, and, Half
Haskell, 25 bytes
pred.until(<2)(/2).(+0.5)
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Outputs decimals, one-indexed without the initial zero term.
Adds 0.5 to the input, then halves ...
- 146k
20
votes
16
votes
Accepted
Parse a Unicode vulgar fraction
Raku, 17 bytes
{S!\⅟!1/!.EVAL}
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Returns a rational number type. Raku actually natively supports unicode literals and operators, though it doesn't ...
- 47.4k
16
votes
Next digit of rational number
Regex (ECMAScript or better), 38 34 20 bytes
((.).*),?(.*)\1,?\3$
Uses , as the decimal separator. Returns its output as ...
- 11.7k
15
votes
Accepted
Simplify a continued fraction
J, 8 5 bytes
Same as this, but uses a build-in for rationals.
Argument is {a0,a1,a2,a3,...} as a list of J extended precision rational numbers. Result is the fraction as a J extended precision ...
- 30.9k
15
votes
Find Index of Rational Number in Calkin-Wilf Sequence
JavaScript (ES6), 33 bytes
Expects a pair of integers (p,q) representing the fraction \$p/q\$.
...
- 195k
15
votes
Rabinowitz-Wagon \$\pi\$ formula
Python, 71 70 60 57 bytes
f=lambda n,q=1,p=1:n and f(n-1,q:=q*2*n+q,p*n+q)or(2*p,q)
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Outputs the (0-indexed) nth term of the sequence as a (...
- 561
14
votes
Simplify a continued fraction
GolfScript, 13 bytes
~]-1%{\-1?+}*
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Yay for GolfScript's hidden rationals. :)
Explanation
GolfScript's only "official" number type is integers. ...
- 197k
14
votes
Simplify a continued fraction
Haskell, 37 36 18 bytes
foldr1$(.(1/)).(+)
This function expects Haskell's Ratio type as input. Usage example:
...
- 35.9k
14
votes
Accepted
Infinitely Print Zeno's Dichotomy Paradox (1/(2^n))
05AB1E, 10 9 bytes
Saved 1 byte thanks to Erik the Outgolfer
[No…+1/J?
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Explanation
...
- 53k
14
votes
14
votes
Accepted
Round towards zero
Jelly, 1 byte
r
A full program (as a monadic Link it returns a list of length one).
Try it online!
How?
...
- 109k
14
votes
Phony fractions
J, 22 bytes
%&".e.=/#&,%/&(1".\.])
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quick explanation for now:
take the input as strings
...
- 33.7k
14
votes
Repetend length in 1/n
Jelly, 6 bytes
R⁵*%i1
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Basically compute 10**[1..n] % n and get the 1-based index of ...
- 78.2k
14
votes
Quoted rational numbers
J, 25 bytes
(%-.)~/@(10^#&>)#.10#.&>]
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Takes a boxed 2-item vector containing the digit vectors of \$x\$ and \$y\$, and returns a ...
- 78.2k
13
votes
Simplify a continued fraction
LabVIEW, 36 equivalent bytes
Fairly straight forward naive implementation using OP's algorithm. Is there a nicer way to do this?
- 441
13
votes
Is it within the Cantor set?
Mathematica, 54 bytes
If[Last@#===1,Most@#,#]&@RealDigits[#,3][[1]]~FreeQ~1&
Unnamed function taking a fraction x/y ...
- 15.9k
13
votes
Infinitely Print Zeno's Dichotomy Paradox (1/(2^n))
Python 2, 30 bytes
-5 thanks to Erik the Outgolfer
i=1
while 1:print i,'+1/';i*=2
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- 2,421
13
votes
I want my book to be away from this table
Octave, 41 40 33 bytes
1 byte saved thanks to @Dennis
@(n)find(cumsum(.5./(1:9^n))>n,1)
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Explanation
This uses the fact that harmonic numbers can ...
- 105k
13
votes
Ryley's Theorem
PARI/GP, 35 bytes
r->[x=r+1/3,-x+r/3/d=x^2-r,1/9/d-1]
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PARI/GP, 40 bytes
...
- 49.3k
13
votes
Iterate your way to a fraction
Python, 54 bytes (-1 @Jonathan Allan, -1 me)
f=lambda n,d:n and'gf'[p:=n*d>0]+f(p*n-d,[n,d][p])or''
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Old Python, 56 bytes (@tsh)
f=lambda n,d:n*d<0and'g&#...
- 16.7k
13
votes
Egyptian fraction representations of 1
Vyxal, 10 bytes
¡ɾṗ'Ė∑1=;t
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Bruteforcer. \$O\left(2^{n!}\right)\$ time complexity, searches for fractions with reciprocals \$ n! \$ which seems to be ...
- 510
13
votes
Infinite Candle Sequence
Python, 31 bytes
f=lambda a:a and(f(a//2)+a%2)/2
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Returns the nth term (0-based) as a float.
Python, 54 bytes
a=b=0
while[print(int(bin(a)[:1:-1],2)/-~b)]:a+=1;b|=a
Attempt This ...
- 16.7k
13
votes
Find Index of Rational Number in Calkin-Wilf Sequence
PARI/GP, 29 bytes
f(x)=if(x,1+f(-1\-x*2-1-1/x))
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\$\begin{align}f(0)&=0\\f(x)&=1+f(2\lceil1/x\rceil-1-1/x)\end{align}\$
- 49.3k
12
votes
Delete the first periodic digit
Wolfram Language (Mathematica), 59 bytes
FromDigits@MapAt[RotateLeft@*List@@#&,RealDigits@#,{1,-1}]&
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Explanation
...
- 13.8k
12
votes
Phony fractions
Python 3, 86 bytes
lambda a,b:g(a)&g(b)
g=lambda s:{(int(s[:i]+s[i+1:])/int(s),x)for i,x in enumerate(s)}
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-8 bytes thanks to ovs
Making use ...
- 7,684
12
votes
Egyptian fraction representations of 1
Wolfram Language (Mathematica), 32 bytes
Using Sylvester's sequence A000058
Nest[##&[#^2+#,1+#,##2]&,1,#-1]&
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-8 bytes from @att
- 24.9k
Only top scored, non community-wiki answers of a minimum length are eligible