Pavol Pidanič

Hackerrank – Alien Username

Problem Statement A description of the problem can be found on Hackerrank. Solution Regular Expression that validates input username: ^[_\.]\d+[a-zA-Z]*_?$ I created solution in: Java JavaScript Scala Ruby All solutions are also available on my GitHub. Java

import java.util.Scanner;

public class AlienUsername
{
    public static void main(String[] args)
    {
        Scanner scanner = new Scanner(System.in);
        int testCases = scanner.nextInt();
        for (int i = 0; i < testCases; i++)
        {
            String input = scanner.next();
            if(input.matches("[_\\.]\\d+[a-zA-Z]*_?"))
            {
                System.out.println("VALID");
            }
            else
            {
                System.out.println("INVALID");
            }
        }
        scanner.close();
    }
}

import java.util.Scanner;

public class AlienUsername

{

public static void main(String[] args)

{

Scanner scanner = new Scanner(System.in);

int testCases = scanner.nextInt();

for (int i = 0; i < testCases; i++)

{

String input = scanner.next();

if(input.matches("[_\\.]\\d+[a-zA-Z]*_?"))

{

System.out.println("VALID");

}

else

{

System.out.println("INVALID");

}

scanner.close();

}

JavaScript

function processData(input) {
    var lines = input.split("\n");
    for(var i = 1; i < lines.length; i++) {
        if(lines[i].match(/^[_\.]\d+[a-z]*_?$/ig)) {
            console.log("VALID");
        } else {
            console.log("INVALID");
        }
    }
}

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
    processData(_input);
});

function processData(input) {

var lines = input.split("\n");

for(var i = 1; i < lines.length; i++) {

if(lines[i].match(/^[_\.]\d+[a-z]*_?$/ig)) {

console.log("VALID");

} else {

console.log("INVALID");

}

process.stdin.resume();

process.stdin.setEncoding("ascii");

_input = "";

process.stdin.on("data", function (input) {

_input += input;

});

process.stdin.on("end", function () {

processData(_input);

});

Scala

import scala.io.Source

object AlienUsername extends App {
  val usernames = Source.stdin.getLines().drop(1)

  println(usernames.map(validateUsername).mkString("\n"))

  def validateUsername(name: String): String = {
    if (name.matches("[_\\.]\\d+[a-zA-Z]*_?"))
      return "VALID"
    else
      return "INVALID"
  }
}

import scala.io.Source

object AlienUsername extends App {

val usernames = Source.stdin.getLines().drop(1)

println(usernames.map(validateUsername).mkString("\n"))

def validateUsername(name: String): String = {

if (name.matches("[_\\.]\\d+[a-zA-Z]*_?"))

return "VALID"

else

return "INVALID"

}

Ruby

n = gets.to_i
n.times do
  name = gets.to_s.strip
  if /[_\.]\d+[a-zA-Z]*_?/ =~ name
    puts "VALID"
  else
    puts "INVALID"
  end
end

n = gets.to_i

n.times do

name = gets.to_s.strip

if /[_\.]\d+[a-zA-Z]*_?/ =~ name

puts "VALID"

else

puts "INVALID"

end

Hackerrank – Chocolate Feast

Problem Statement A description of the problem can be found on Hackerrank. Solution Calculate count of chocolates: chocolates = money / price . Count of chocolates is count of wrappers, too. Free chocolates are calculated: divide chocolates with count of chocolates needed for discount add solution of the division to chocolates new wrappers count is: […]

Hackerrank – Cavity Map

Problem Statement A description of the problem can be found on Hackerrank. Solution Filter all matrix indexes that are at the periphery. For all the rest choose one index and compare its value with all neighbours (left, right, up, down). If it is greater than all neighbours, replace it with ‘X’. I created solution in […]

Hackerrank – Service Lane

Problem Statement A description of the problem can be found on Hackerrank. Solution Find minimum in given array from index i to j. I created solution in 4 languages: Scala Java JavaScript Ruby All solutions are also available on my GitHub. Scala

object ServiceLane extends App {
  val lines = io.Source.stdin.getLines().toList
  val lanes = lines(1).split(" ").map(_.toInt)
  val segments = lines.drop(2)
  val vehicles = segments.map(width(lanes, _))
  println(vehicles.mkString("\n"))

  def width(lanes: Array[Int], inputLane: String): Int = {
    val arr = inputLane.split(" ").map(_.toInt)
    lanes.slice(arr(0), arr(1) + 1).min
  }
}

object ServiceLane extends App {

val lines = io.Source.stdin.getLines().toList

val lanes = lines(1).split(" ").map(_.toInt)

val segments = lines.drop(2)

val vehicles = segments.map(width(lanes, _))

println(vehicles.mkString("\n"))

def width(lanes: Array[Int], inputLane: String): Int = {

val arr = inputLane.split(" ").map(_.toInt)

lanes.slice(arr(0), arr(1) + 1).min

}

Java

import java.util.Scanner;

public class ServiceLane
{
    private static final int BIKE = 1;
    private static final int TRUCK = 3;

    public static void main(String[] args)
    {
         Scanner scanner = new Scanner(System.in);
         int laneLength = scanner.nextInt();
         int testCases = scanner.nextInt();
         int[] laneWidth = new int[laneLength];
         for (int i = 0; i < laneLength; i++)
         {
             laneWidth[i] = scanner.nextInt();
         }
         for (int j = 0; j < testCases; j++)
         {
             int laneEntry = scanner.nextInt();
             int laneExit = scanner.nextInt();
             System.out.println(largestVehicle(laneWidth, laneEntry, laneExit));
         }
         scanner.close();
    }

    private static int largestVehicle(int[] laneWidth, int laneEntry, int laneExit)
    {
         int car = TRUCK;
         while (car > BIKE && laneExit >= laneEntry)
         {
             if(laneWidth[laneEntry] < car)
             {
                 car = laneWidth[laneEntry];
             }
             laneEntry++;
         }
         return car;
    }
}

import java.util.Scanner;

public class ServiceLane

{

private static final int BIKE = 1;

private static final int TRUCK = 3;

public static void main(String[] args)

{

Scanner scanner = new Scanner(System.in);

int laneLength = scanner.nextInt();

int testCases = scanner.nextInt();

int[] laneWidth = new int[laneLength];

for (int i = 0; i < laneLength; i++)

{

laneWidth[i] = scanner.nextInt();

}

for (int j = 0; j < testCases; j++)

{

int laneEntry = scanner.nextInt();

int laneExit = scanner.nextInt();

System.out.println(largestVehicle(laneWidth, laneEntry, laneExit));

}

scanner.close();

}

private static int largestVehicle(int[] laneWidth, int laneEntry, int laneExit)

{

int car = TRUCK;

while (car > BIKE && laneExit >= laneEntry)

{

if(laneWidth[laneEntry] < car)

{

car = laneWidth[laneEntry];

}

laneEntry++;

}

return car;

}

JavaScript

function processData(input) {
    var lines = input.split('\n');
    var lanes = lines[1].split(' ').map(function(item) {return parseInt(item)});
    for(var i = 2; i < lines.length; i++) {
        var arr = lines[i].split(' ').map(function(item) {return parseInt(item)});
        console.log(findMin(lanes, arr[0], arr[1]));
    }
}

function findMin(arr, i, j) {
    var min = 10000000;
    for(var k = i; k <= j; k++) {
        if(arr[k] < min) {
            min = arr[k];
        }
    }
    return min;
}

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
    processData(_input);
});

function processData(input) {

var lines = input.split('\n');

var lanes = lines[1].split(' ').map(function(item) {return parseInt(item)});

for(var i = 2; i < lines.length; i++) {

var arr = lines[i].split(' ').map(function(item) {return parseInt(item)});

console.log(findMin(lanes, arr[0], arr[1]));

}

function findMin(arr, i, j) {

var min = 10000000;

for(var k = i; k <= j; k++) {

if(arr[k] < min) {

min = arr[k];

}

return min;

}

process.stdin.resume();

process.stdin.setEncoding("ascii");

_input = "";

process.stdin.on("data", function (input) {

_input += input;

});

process.stdin.on("end", function () {

processData(_input);

});

Ruby

(length, tests) = gets.split(" ").map{ |i| i.to_i }
lanes = gets.split(" ").map{ |i| i.to_i }

tests.times do
  arr = gets.split(" ").map{ |i| i.to_i }
  puts lanes.slice(arr[0], arr[1] - arr[0] + 1).min
end

(length, tests) = gets.split(" ").map{ |i| i.to_i }

lanes = gets.split(" ").map{ |i| i.to_i }

tests.times do

arr = gets.split(" ").map{ |i| i.to_i }

puts lanes.slice(arr[0], arr[1] - arr[0] + 1).min

end

Hackerrank – Encryption

Problem Statement A description of the problem can be found on Hackerrank. Solution Calculate a width and height of a required matrix: height = ceil(length(input_string) width = floor(length(input_string) Then create a height x width matrix containing a characters from input_string. Transpose the matrix and print all rows. Node: Instead we can print all columns of […]

Ad Infinitum 13 – Math Programming Contest

Hackerrank organized another programming contests from 23.10.2015 17:30 CEST to 25.10.2015 CET called Ad Infinitum 13 – Math Programming Contest, which I participaded in. It was my 12th contest at Hackerrank and I think I was quite successfull. I was able to solve 3 challenges and earned full points: Game with coins Integral Points The […]

Hackerrank – Evaluating e^x

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

object EvaluatingEx extends App {
  def f(x: Double): Double =
    {
      f2(x, 9)
    }

  def fact(x: Int): Int = if (x <= 1) 1 else x * fact(x - 1)

  def f2(x: Double, i: Int): Double =
    {
      if (i == 0) 1 else Math.pow(x, i) / fact(i) + f2(x, i - 1)
    }

  val n = readInt
  (1 to n) foreach (x => println(f(readFloat())))
}

object EvaluatingEx extends App {

def f(x: Double): Double =

{

f2(x, 9)

}

def fact(x: Int): Int = if (x <= 1) 1 else x * fact(x - 1)

def f2(x: Double, i: Int): Double =

{

if (i == 0) 1 else Math.pow(x, i) / fact(i) + f2(x, i - 1)

}

val n = readInt

(1 to n) foreach (x => println(f(readFloat())))

}

Solution also available on my GitHub.

Hackerrank – Update List

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

object UpdateList extends App {
  def f(arr: List[Int]): List[Int] = 
    if (arr.isEmpty) Nil else arr.head.abs :: f(arr.tail)
}

object UpdateList extends App {

def f(arr: List[Int]): List[Int] =

if (arr.isEmpty) Nil else arr.head.abs :: f(arr.tail)

}

Solution also available on my GitHub.

Hackerrank – List Length

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

object ListLength extends App {

  def f(arr: List[Int]): Int = {
    var count = 0
    for (i <- arr) count += 1
    count
  }
  
  println(f(io.Source.stdin.getLines.toList.map(_.trim).map(_.toInt)))
}

object ListLength extends App {

def f(arr: List[Int]): Int = {

var count = 0

for (i <- arr) count += 1

count

}

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

}

Solution also available on my GitHub.

Hackerrank – Sum of odd elements

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

object SumOddElements extends App{
   def f(arr:List[Int]):Int = arr.filter(_ % 2 != 0).sum
}

object SumOddElements extends App{

def f(arr:List[Int]):Int = arr.filter(_ % 2 != 0).sum

}

Solution also available on my GitHub.