Archives functional programming - Page 3 of 3

Hackerrank – List Replication

Problem Statement A description of the problem can be found on Hackerrank. Solution

object ListReplication extends App {

  def f(num: Int, arr: List[Int]): List[Int] = if (arr.isEmpty) Nil 
                            else List.fill(num)(arr.head) ::: f(num, arr.tail)

  def f2(num: Int, arr: List[Int]): List[Int] =
    arr match {
      case x :: xs => List.fill(num)(x) ::: f2(num, xs)
      case Nil => Nil
    }

  def displayResult(arr: List[Int]) = println(f(arr(0).toInt, arr.drop(1)).map(_.toString).mkString("\n"))

  displayResult(io.Source.stdin.getLines.toList.map(_.trim).map(_.toInt))
}

object ListReplication extends App {

def f(num: Int, arr: List[Int]): List[Int] = if (arr.isEmpty) Nil

else List.fill(num)(arr.head) ::: f(num, arr.tail)

def f2(num: Int, arr: List[Int]): List[Int] =

arr match {

case x :: xs => List.fill(num)(x) ::: f2(num, xs)

case Nil => Nil

}

def displayResult(arr: List[Int]) = println(f(arr(0).toInt, arr.drop(1)).map(_.toString).mkString("\n"))

displayResult(io.Source.stdin.getLines.toList.map(_.trim).map(_.toInt))

}

Solution also available on my GitHub.

Hackerrank – Hello World N Times

Problem Statement A description of the problem can be found on Hackerrank. Solution

object HelloWorldNTimes extends App {
  def f2(i: Int): Unit = println("Hello World")

  def f(n: Int) = (1 to n).foreach(f2(_))

  var n = readInt
  f(n)
}

object HelloWorldNTimes extends App {

def f2(i: Int): Unit = println("Hello World")

def f(n: Int) = (1 to n).foreach(f2(_))

var n = readInt

f(n)

}

Solution also available on my GitHub.

Hackerrank – Hello World

Problem Statement A description of the problem can be found on Hackerrank. Solution

object HelloWorld extends App {
  def f() = println("Hello World")

  f()
}

object HelloWorld extends App {

def f() = println("Hello World")

f()

}

Solution also available on my GitHub.

Hackerrank – Solve me first FP

Problem Statement A description of the problem can be found on Hackerrank. Solution

object SolveMeFirst {
  def main(args: Array[String]) {
    println(io.Source.stdin.getLines().take(2).map(_.toInt).sum)
  }
}

object SolveMeFirst {

def main(args: Array[String]) {

println(io.Source.stdin.getLines().take(2).map(_.toInt).sum)

}

Solution also available on my GitHub.

Hackerrank – String Reductions

Problem Statement A description of the problem can be found on Hackerrank. Solution

object StringReductions extends App {
  println(io.Source.stdin.getLines().toList.head.distinct)
}

object StringReductions extends App {

println(io.Source.stdin.getLines().toList.head.distinct)

}

Solution also available on my GitHub.

Hackerrank – Pascal’s Triangle

Problem Statement A description of the problem can be found on Hackerrank. Solution I created recursive function for factorial . Then create all combinations of rows and column indexes. For input 4 it looks like:

(0,0)
(1,0), (1,1)
(2,0), (2,1), (2,2)
(3,0), (3,1), (3,2), (3,3)

(0,0)

(1,0), (1,1)

(2,0), (2,1), (2,2)

(3,0), (3,1), (3,2), (3,3)

Apply function for pascal triangle for each combination. I created solution in Scala: The solution […]

Pavol Pidanič

I can count to 1023 with 10 fingers

Tag: functional programming

Hackerrank – List Replication

Hackerrank – Hello World N Times

Hackerrank – Hello World

Hackerrank – Solve me first FP

Hackerrank – String Reductions

Hackerrank – Pascal’s Triangle