# Tag Info

### I reverse the source code, you negate the input!

Knight, 5 bytes O P~O Try It Online! Try It Online reversed!

### I reverse the source code, you negate the input!

Ly, 3 bytes +0- Try it online! Forwards: ...
1 vote

### Generate a Kirkman triple system

PARI/GP, 218 bytes ...

### I reverse the source code, you negate the input!

sed, 14 bytes #//--/s;/-/^/s The code is only comment, which means the input is outputted unchanged. Attempt This Online! Reversed: ...

### I reverse the source code, you negate the input!

Alice, 11 bytes \ X'@ /I-O/ Try it online! !enilno ti yrT Operates entirely within ordinal mode. The negation is done by taking string symmetric difference ...

### I reverse the source code, you negate the input!

Alice, 15 bytes /O\ /I@ @I/R\O/ Try it online! !enilno ti yrT Flattened Original I O@, reads from the input, output Reversed <...

### The inverse Collatz Conjecture

dc, 35 bytes [3*1+]0:s[1-2/]1:s[pd2%;sxd0<l]dslx Try it online!
1 vote

### Are they collinear?

Vyxal, 4 bytes v-ÞḊ Try it Online! Outputs 0 for truthy and any other integer for falsy. Port of fireflame241's Jelly answer. ...

### I reverse the source code, you negate the input!

dc, 5 bytes dp-r0 Try it online!
1 vote

### Anti-divisors of a number

Nibbles, 8 bytes (16 nibbles) >>|,$~-!=$*%@\$~~ ...
1 vote

### How many steps does it take from n to 1 by subtracting the greatest divisor?

dc, 39 bytes 0[1+rd[d3R1-d_4R%0<t]dstxr-d_3R1<l]dslx Try it online! Takes input as number on top of stack, and leaves result as top of stack
1 vote

R, 30+24=54 bytes Cartesian to polar, 30 bytes $$x,y)c(Mod(z<-x+1i*y),Arg(z)) Attempt This Online! No imaginary numbers for +2: ... 2 votes ### Cartesian - polar conversion couple x86 64-bit machine code, 23 + 13 = 36 bytes D9 06 D9 07 D9 F3 D9 07 D8 C8 D9 06 D8 C8 DE C1 D9 FA D9 1E D9 1F C3 D9 07 D9 FB D8 0E D9 1F D8 0E D9 1E C3 Try it ... 1 vote ### Anti-divisors of a number x86 64-bit machine code, 26 bytes 89 F1 51 8D 44 71 01 99 01 C9 F7 F1 58 83 FA 02 77 01 AB 91 E2 EC FF 4F FC C3 Try it online! Takes $n$ in ESI and writes the ... 2 votes ### Cartesian - polar conversion couple 05AB1E (legacy), 7 + 22 = 29 bytes Polar to Cartesian (7 bytes): .¾¹.½‚* Loose inputs in the order $\phi,r$; outputs as a pair $[x,y]$. Try it online or verify ... 1 vote ### Are the numbers amicable? Vyxal, 5 bytes ∆KUṘ⁼ Try it Online! 1 vote ### Divisor reduction Vyxal l, 5 bytes ≬KL-İ Try it Online! Flagless: Vyxal, 6 bytes ≬KL-İL Try it Online! 3 votes ### Cartesian - polar conversion couple Factor, 16 + 15 = 31 bytes [ rect> >polar ] Try it online! [ cis * >rect ] Try it online! ... 1 vote ### Cartesian - polar conversion couple PARI/GP, 34 + 24 = 58 bytes f(x,y)=[abs(z=x+I*y),if(z,arg(z))] g(r,a)=r*[cos(a),sin(a)] Attempt This Online! 8 votes ### Cartesian - polar conversion couple Python, 49 + 48 = 97 bytes -2 thanks to @Seb lambda r,a,n=9e9:((x:=r*(a/n-1j)**n).real,x.imag) Attempt This Online! lambda x,y,n=1e-9:(abs(c:=x+1j*y),(c**n).imag/n) Doesn't use any libraries, no exp, ... 0 votes ### Find a Fixed Point J, 3 bytes ^:_ Try it online! When a conjunction in J is missing an operand, it becomes an adjective. This program produces an adjective which takes as an argument ... 1 vote ### Cartesian - polar conversion couple SageMath, 69 68 bytes lambda x,y:((x^2+y^2)^.5,arctan2(y,x)) lambda r,t:(r*cos(t),r*sin(t)) Try it online! Adjusted score correctly thanks to Steffan. Saved a ... 0 votes ### Find a Fixed Point Vyxal, 1 byte Try it Online! Builtin lol 1 vote ### Find a Fixed Point dc, 30 bytes [pq][Smrd3Rd3Rxd3R=mLmlmx]dsmx Try it online! Takes as input the function in the form of a macro and initial value on the stack(pushed in that order). ... 2 votes ### Cartesian - polar conversion couple MATLAB/Octave, 9+9=18 bytes, builtins Simple builtins, convert between (x,y) and (angle[radians],radius) Cartesian to polar: @cart2pol Try it online! Polar to ... 3 votes ### Cartesian - polar conversion couple J 10 (5 + 5) to polar, 5 bytes *.@j. Try it online! to cartesian, 5 bytes +.@r. Try it online! Both of these amount to one ... 1 vote ### Cartesian - polar conversion couple lin, 28 + 17 = 45 bytes To Polar ([a b] -> [a b]): "2^._ +.5^""._.~ atant", Q To Cartesian (... 5 votes ### Cartesian - polar conversion couple Wolfram Language (Mathematica), 14+11=25 bytes AbsArg[#+I#2]& AngleVector Try it online! Input [x,y]/... 2 votes ### Cartesian - polar conversion couple Python, 48+48 = 96 bytes lambda*t:(hypot(*t),atan2(*t)) from math import* Attempt This Online! -4 bytes thanks to xnor. lambda a,b:(a*cos(b),a*sin(b)) from math import* Attempt This Online! 1 vote ### Cartesian - polar conversion couple C (gcc), 88 bytes C(x,b,t)float*x,t;{t=x;x=b?*x*sin(t):atan(t/(*x));*x=b?*x*cos(t):sqrt(*x**x+t*t);} 86 bytes 2 bytes can be saved by inverting the order of ... 2 votes ### Cartesian - polar conversion couple APL (Dyalog Classic), 22 + 15 = 37 bytes Cartesian to Polar: 22 bytes {(.5*⍨+/⍵⍺*2),¯3○⍵÷⍺} Polar to Cartesian: 15 bytes ... 3 votes ### Cartesian - polar conversion couple Jelly, 7 + 6 bytes = 13 Polar to Cartesian: ×ıÆe×Æi A dyadic Link accepting $\theta$ on the left and $r$ on the right that yields a list $[x, y]$. Try it ... 1 vote ### Cartesian - polar conversion couple Vyxal, 10 + 7 = 17 bytes Cartesian to Polar, 10 bytes ²∑√?Ṙƒ/∆T" Try it Online! Polar to Cartesian, 7 bytes ⁰₍∆c∆s* Try ... 4 votes ### Cartesian - polar conversion couple Pip -p, 10 + 12 = 22 bytes Polar to Cartesian: a*[CObSIb] Takes angle in radians. Outputs a list containing x and y. Try it ... 4 votes ### Cartesian - polar conversion couple Mathematica, 18+20 = 38 bytes ToPolarCoordinates FromPolarCoordinates Try it online! For the ... 4 votes ### Cartesian - polar conversion couple Desmos, 33+19 = 52 score Both functions take in two arguments representing either polar or Cartesian coordinates (depending on which function is being used), and returns a list representing the ... 1 vote ### Anti-divisors of a number Perl 5 -n, 35 bytes //;map{abs('%_*2-_)<2&&say}2.._ Try it online! Uses a take on xnor's formula in his python ... 1 vote ### Output the nth Even Perfect Number Haskell, 52 bytes ([n|n<-[1..],n==sum[d|d<-[1..div n 2],mod n d<1]]!!) Try it online! Starts at n = 0. Not particularly fast 1 vote ### Anti-divisors of a number lin, 33 bytes .#n.n.<1drop".n.+_ %.~2/ -2^1<".# Try it here! For testing purposes (use -i flag when running ... 1 vote ### Anti-divisors of a number Haskell, 38 bytes h n=[m|m<-[2..n-1],abs(mod n m*2-m)<2] Try it online! 0 votes ### What is the average of n, the closest prime to n, the square of n and the closest Fibonacci number to n? Haskell, 150 bytes ... 4 votes ### Anti-divisors of a number APL (Dyalog Classic), 23 bytes {1↓⍵{(2>|⍵-2×⍵|⍺)/⍵}⍳⍵} Try it online! Usage: ... 1 vote ### Anti-divisors of a number Charcoal, 16 bytes ＮθＩΦ…²θ‹↔⁻⊗﹪θιι² Try it online! Link is to verbose version of code. Explanation: ... 1 vote ### Anti-divisors of a number C (gcc), 58 52 bytes m;f(n){for(m=1;++m<n;)(n%m*2-m)/2||printf("%d ",m);} Try it online! Saved 6 bytes thanks to the suggestion of porting Kevin's ... 2 votes ### Anti-divisors of a number Java 8, 69 64 bytes n->{for(int i=1;++i<n;)if((n%i*2-i)/2==0)System.out.println(i);} -5 bytes thanks to @Deadcode Outputs the results to STDOUT on separated ... 1 vote ### Anti-divisors of a number MathGolf, 13 bytes ╒╞g{_k\%∞-±2< Try it online. Explanation: ... 3 votes ### Anti-divisors of a number 05AB1E, 8 bytes L¦ʒ%·yα! Try it online or verify all test cases. Explanation: ... 3 votes ### Anti-divisors of a number Desmos, 40 bytes l=[1...n][2...] f(n)=l[-2<2mod(n,l)-l<2] Try It On Desmos! Try It On Desmos! - Prettified 5 votes ### Anti-divisors of a number Knight, 40 34 bytes -6 bytes thanks to @Bubbler by looping backwards ;=i=pE P W<1=i-iT&>4^-*2%p i i 2Oi Try It Online! Outputs each anti-divisor in a ... 3 votes ### Delannoy numbers K (ngn/k), 18 bytes {0/x(+':+$$/1,y#1} Try it online! Port of my APL answer that does not use the binomial coefficient built-in. See the linked answer for the ...

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