Hackerrank - Angry Professor

Hackerrank – Problem Statement

A description of the problem can be found on Hackerrank.

Solution

Count all students which come before starting a class (their arrival time is lower or equal to 0). Check if the count of the students is lower than cancellation threshold.

I created solution in:

Scala
Java
JavaScript
Ruby

All solutions are also available on my GitHub.

Java

import java.util.Scanner;

public class AngryProfessor
{
    public static void main(String[] args)
    {
        Scanner stdin = new Scanner(System.in);
        int tests = Integer.parseInt(stdin.nextLine());
        for (int i = 0; i < tests; i++)
        {
            String[] inputs = stdin.nextLine().split(" ");
            int students = Integer.parseInt(inputs[0]);
            int classCancelation = Integer.parseInt(inputs[1]);
            String[] arrivals = stdin.nextLine().split(" ");
            if(classCancelation > studentsBeforeClass(arrivals))
            {
                System.out.println("YES");
            }
            else
            {
                System.out.println("NO");
            }
        }
        stdin.close();
    }

    private static int studentsBeforeClass(String[] arrivals) {
		int result = 0;
		for(int i = 0; i < arrivals.length; i++)
		{
		    if(Integer.parseInt(arrivals[i]) <= 0)
		    {
		        result++;
		    }
		}
		return result;
	}
}

import java.util.Scanner;

public class AngryProfessor

{

public static void main(String[] args)

{

Scanner stdin = new Scanner(System.in);

int tests = Integer.parseInt(stdin.nextLine());

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

{

String[] inputs = stdin.nextLine().split(" ");

int students = Integer.parseInt(inputs[0]);

int classCancelation = Integer.parseInt(inputs[1]);

String[] arrivals = stdin.nextLine().split(" ");

if(classCancelation > studentsBeforeClass(arrivals))

{

System.out.println("YES");

}

else

{

System.out.println("NO");

}

stdin.close();

}

private static int studentsBeforeClass(String[] arrivals) {

int result = 0;

for(int i = 0; i < arrivals.length; i++)

{

if(Integer.parseInt(arrivals[i]) <= 0)

{

result++;

}

return result;

}

JavaScript

'use strict';

const processData = input => {
    const lines = input.split('\n');
    const tests = parseInt(lines[0]);
    let actualLine = 1;
    for(let i = 0; i < tests; i++) {
        const studentsAndCancelation = lines[actualLine++].split(' ').map(i => parseInt(i));
        const cancelation = studentsAndCancelation[1];
        const arrivals = lines[actualLine++].split(' ').map(i => parseInt(i));
        const beforeClass = studentsBeforeClass(arrivals);
        const canceled = cancelation > beforeClass ? "YES" : "NO";
        console.log(canceled);
    }
};

const studentsBeforeClass = (arrivals) => {
    let result = 0;
    for(let i = 0; i < arrivals.length; i++) {
        if(arrivals[i] <= 0) {
            result++;
        }
    }
    return result;
};

process.stdin.resume();
process.stdin.setEncoding("ascii");

var _input = "";
process.stdin.on("data", input => _input += input);
process.stdin.on("end", () => processData(_input));

'use strict';

const processData = input => {

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

const tests = parseInt(lines[0]);

let actualLine = 1;

for(let i = 0; i < tests; i++) {

const studentsAndCancelation = lines[actualLine++].split(' ').map(i => parseInt(i));

const cancelation = studentsAndCancelation[1];

const arrivals = lines[actualLine++].split(' ').map(i => parseInt(i));

const beforeClass = studentsBeforeClass(arrivals);

const canceled = cancelation > beforeClass ? "YES" : "NO";

console.log(canceled);

}

};

const studentsBeforeClass = (arrivals) => {

let result = 0;

for(let i = 0; i < arrivals.length; i++) {

if(arrivals[i] <= 0) {

result++;

}

return result;

};

process.stdin.resume();

process.stdin.setEncoding("ascii");

var _input = "";

process.stdin.on("data", input => _input += input);

process.stdin.on("end", () => processData(_input));

Scala

import scala.io.Source

object AngryProfessor extends App {
  val lines = Source.stdin.getLines().drop(1)
  val inputs = lines.grouped(2).map(_.toList)
  inputs.foreach {
    input => {
      val studentsAndCancelation = input(0).split("\\s+").map(_.toInt)
      val students = studentsAndCancelation(0)
      val cancelation = studentsAndCancelation(1)
      val arrivals = input(1).split("\\s+").map(_.toInt)
      val cancelled = if(cancelation > studentsBeforeClass(arrivals)) "YES" else "NO"
      println(cancelled)
    }
  }

  def studentsBeforeClass(arrivals: Array[Int]): Int = {
    arrivals.count(_ <= 0)
  }
}

import scala.io.Source

object AngryProfessor extends App {

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

val inputs = lines.grouped(2).map(_.toList)

inputs.foreach {

input => {

val studentsAndCancelation = input(0).split("\\s+").map(_.toInt)

val students = studentsAndCancelation(0)

val cancelation = studentsAndCancelation(1)

val arrivals = input(1).split("\\s+").map(_.toInt)

val cancelled = if(cancelation > studentsBeforeClass(arrivals)) "YES" else "NO"

println(cancelled)

}

def studentsBeforeClass(arrivals: Array[Int]): Int = {

arrivals.count(_ <= 0)

}

Ruby

def before_class(arrivals)
  result = 0
  arrivals.each do |item|
    result += 1 if item <= 0
  end
  return result
end

tests = gets.to_i
tests.times do |i|
  (students, cancelation) = gets.split(" ").map {|i| i.to_i}
  arrivals = gets.split(" ").map {|i| i.to_i}
  before = before_class(arrivals)
  if(cancelation > before)
    puts "YES"
  else
    puts "NO"
  end
end

def before_class(arrivals)

result = 0

arrivals.each do |item|

result += 1 if item <= 0

end

return result

end

tests = gets.to_i

tests.times do |i|

(students, cancelation) = gets.split(" ").map {|i| i.to_i}

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

before = before_class(arrivals)

if(cancelation > before)

puts "YES"

else

puts "NO"

end

Pavol Pidanič

I can count to 1023 with 10 fingers

Hackerrank – Angry Professor