Search
Factor, 108 bytes USING: assocs kernel math math.primes.factors ; IN: s : ? ( n -- ? ) group-factors [ nip 2 < ] assoc-all? ;
Myby, 12 5 bytes primf=primfd primf : prime factors = : equals primfd : unique prime factors Evaluated as a monadic fork in J (f y) g (h y). The test cases (retest...
Vyxal, 4 bytes KƛtO Try it Online! Explained KƛtO Kƛ # For each prefix of the input tO # How many times does the tail occur in the prefix?
Scala, 52 bytes Stream.from(1).filter(x=>x%(x+"":\0)(_+_-48)<1).take Try it in Scastie! Woo, 3 deprecation warnings! (okay, one of them could be fixed but I like to live dangerously) St...
Vyxal, 1 byte Ċ Try it Online! Yes, there really is a built-in for this.
Vyxal, 4 bytes ‡∑Ḋȯ Try it Online! Explained ‡∑Ḋȯ ‡ ȯ # Find the first input numbers where: ∑ # The sum Ḋ # Divides that number
Challenge A Niven number is a positive integer which is divisible by the sum of its digits. For example, 81 -> 8+1=9 -> 81%9=0. Your task is to find the first n Niven numbers, given n. Te...
ESCR, 17 bytes show [and [in] 1] ESCR has no way to read from standard input (currently), so I assumed the existence of the function IN which magically returns the user input. Since the user i...
Myby, 2 bytes %2 Input is taken from the command line implicitly. 0 for even, 1 for odd. Since Myby is still in its early stages, there is no online sandbox. Some test cases can be seen here.
Python 3, 74 bytes def f(a): d={x:0 for x in a};r=[] for x in a:d[x]+=1;r+=[d[x]] return r Try it online!
Python 3.8 (pre-release), 69 bytes def f(x,y={},z=[]): for i in x:y[i]=y.get(i,0)+1;z+=[y[i]] return z Try it online! Bonus: theoretical answer if python allowed named assignment with su...
J, 9 bytes 1#.]=&><\ This is the 7 byte APL solve but makes use of #. in place of +/"1. I came up with 1#.]=[\ first, but bubbler pointed out it breaks when non zeros are present. At...
J, 24 char ([: +/ [: (* +/\ )"1 ~. ="0 1 ]) Sample Runs ([:+/[:(*+/\)"1~.="0 1]) 1 1 2 2 2 1 1 1 3 3 1 2 1 2 3 3 4 5 1 2 ([:+/[:(*+/\)"1~.="0 1]) 3 7 5 4 9 2 3 2 6 6 1 1 1 1 1 1 2 ...
Lua, 98 bytes function(t)r={}for k,v in pairs(t)do r[v]=0 end for k,v in pairs(t)do r[v]=r[v]+1 end return r end Attempt This Online!
C (gcc), 45, 42 bytes t[9999];f(s,a)int*a;{for(;s;)t[a[--s]]++;} Try it online! Assumptions: Passing the array size to a function can be used as a means to deal with empty arrays (not s...
J, 8 bytes ~.,:#/.~ Tacit function, this is the de facto method for this problem in J. Attempt it online!
Python 3, 38 36 33 bytes lambda x:{n:x.count(n)for n in x} -2 bytes thanks to @Razetime Another -3 bytes thanks to @orthoplex Attempt it online!
APL(Dyalog Unicode), 4 bytes SBCS Anonymous tacit prefix function. ,∘≢⌸ Try it on APLgolf! …⌸ between each unique element and its indices, apply: ,∘≢ concatenate the unique element to the ta...
JavaScript (Node.js), 38 32 bytes -6 bytes thanks to Shaggy! a=>a.map(v=>d[v]=-~d[v],d={})&&d Try it online! Basically just this but returning the result
Challenge Given an array in any suitable format, create a frequency table for it. i.e: Pair each unique element with the number of times it appears in the array. You can return the frequency tabl...
Function parameters should not be allowed to be used in place of a return value. Reasons: Terms like return value and function result are explicitly specified as a specific, formal language i...
C (gcc), 358 bytes static inline _Noreturn float f(union u);extern _Thread_local _Complex long double*restrict B;main(void){_Atomic register enum {A};typedef _Alignas(unsigned char)struct S;_Sta...
