rorick Bad problem description for Clojure.
Description states to copy template and fill blank:
(fn[n]___________________________)But prepared caller part of solution is
(hello_word_n_times n)and is not editable. It will not compile if one copies template and fills blanks. Temlate must be(defn hello_word_n_times [n]___________________________)or(def hello_word_n_times (fn[n]___________________________)).BTW, there's also a misspelling in calling part that cannot be edited: word instead of wor**l**d.
I'm starting to suspect, that guys from Hackerrank do not really like Clojurists) Another surprise waiting Hackerrank student on his way of learning FP in Clojure is when his tested and submitted solution will fail with compile error. That's most likely because of version mismatch. Described environment is Clojure 1.9 and that is what anyone expects, but in reality it is ancient Clojure 1.6.
Katajam Thank you. I was trying hard to figure out the compile error as a person who never code in this language before...
christopher_lil1 My version in Haskell:
hello_worlds n = mapM_ putStrLn $ replicate n "Hello World"
nitinradkeirctc mine is same hello_worlds n = mapM_ putStrLn (take n (repeat "Hello World"))
Edka Imparetive looking way to do it in Haskell:
hello_worlds n = forM_ [1..n] $ \_ -> putStrLn "Hello World"
alsuga Lang: Haskell
I'm learning haskell, if someone have a suggestion or a correction please let me knowhello_worlds 1 = putStrLn "Hello World" hello_worlds n = do putStrLn "Hello World" hello_worlds (n - 1) main = do n <- readLn :: IO Int hello_worlds n
sfelde21 what does this line do?
hello_worlds 1 = putStrLn "Hello World"
aleksei_maide I wasn't sure either (new to haskell), but apparently it's a stop condition. (If the input to the function is 1 then it simply does the following: putStrLn "Hello World")
Hertzz I've had many issues with this mostly bc of the function getManyLines that editor provides and I've ended up cutting it down to basicly your hello_worlds. It prints hello world ten times, and the editor is still saying the outpust is wrong. Also, shouldn't haskell functions be defined for all possible inputs? Does anybody have good sources for learning Haskell? turns out to be much more difficult then object oriented Langs
uvaprakashp Scala version
def f(n: Int) = println("Hello World\n" * n)
xiang19950505 My version in Haskell:
import Control.Monad (replicateM_) hello_worlds :: Int -> IO () hello_worlds n = replicateM_ n $ putStrLn "Hello World"
antonio_net There is my Clojure solution:
(defn hello_word_n_times[n] (if (not= n 0) (do (println "Hello World") (recur (dec n)))))
darren_m_k My version in F#:
open System List.iter (fun _ -> printfn "Hello World") [1..(int (Console.ReadLine()))]
ben_knoble Functional scala approach:
def hello = println("Hello World") def f(n) = 1 to n map (i => hello)
Sri1998 What's the problem with this racket code (not compiling)? Works fine in Dr Racket compiler.
(define (hpr x) (if (= x 1) "Hello World" (string-append "Hello World \n " (hpr (- x 1))))) (let ([n (read)]) (printf "~a~%" (hpr n)))
ravi_andrew_baj1 Yeah, this code seems perfect but I think it needs attention as it refuses to run as it usually must. This is the error message:
Compile time error Compile Message load-handler: expected a
module' declaration forsolution' in #, but found something else compilation context...: solution.rkt context...: /usr/share/racket/collects/syntax/modcode.rkt:62:2: reader /usr/share/racket/collects/syntax/modcode.rkt:279:5: compile-one /usr/share/racket/collects/compiler/cm.rkt:363:0: compile-zo* /usr/share/racket/collects/compiler/cm.rkt:572:26 /usr/share/racket/collects/compiler/cm.rkt:564:42 /usr/share/racket/collects/compiler/cm.rkt:644:2: do-check /usr/share/racket/collects/compiler/cm.rkt:737:4 /usr/share/racket/pkgs/compiler-lib/compiler/commands/make.rkt:81:8: for-loop /usr/share/racket/pkgs/compiler-lib/compiler/commands/make.rkt: [running body] /usr/share/racket/collects/raco/raco.rkt: [running body] /usr/share/racket/collects/raco/main.rkt: [running body] Exit Status 255
xxiane I'm getting a weird error message:
Solution.scala:16: error: not found: value f f(n) ^ one error found
Here's everything I have (Scala):
object Solution extends App { object Solution { def main(args: Array[String]) { val sc = new java.util.Scanner (System.in); var n = sc.nextInt(); def f(n: Int) = { for(i <- 0 until n) { println("Hello World"); } } } } var n = scala.io.StdIn.readInt f(n) }
Am I just putting the f(n) in the wrong place?
ObaidGill [deleted]ObaidGill object Solution { def main(args: Array[String]) { val sc = new java.util.Scanner (System.in); var n = sc.nextInt(); } } def f(n: Int) : Unit = { for (i <- 1 to n) { println("Hello World") } }
singh_r1115 keep the function f directly in the pane remove all other code like below
def f(n:Int):Unit = { for(i <- 1 to n) Console println "Hello World" }
PitrDubovich Or, using
foreach:def f(n:Int):Unit = { (1 to n).foreach (_ => println("Hello World")) }
binoyyj Can someone please explain this code? I'm new to Scala.
PitrDubovich In the code above:
def f(n:Int):Unit = { (1 to n).foreach (_ => println("Hello World")) }
We define a function,
f, which takes one integer argument,n, and returnsUnitwhich is sort of likevoidin Java (because we don't need to return anything in particular, as the purpose of the function is to print the output "Hello World", not return it).The function works by calling the
tomethod of theIntclass(1 to n)which creates aRange. Range has a methodforEach, which applies a function to each element in the range.The function applied to each element of the Range 1..n is this part of the code:
_ => println("Hello World"). The Range class calls this function over and over again, each time passing in one of the values from 1 to n (so: 1, then 2, then 3, etc), but because we don't need to know which element we are currently on just to printHello World, we ignore that argument, which is why we name it underscore (_).binoyyj Understood. Thank you for the detailed explaination!
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