Hackerrank - Plus Minus - Pavol Pidanič

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

Solution
After reading all numbers in array, you have to filter this array according to three conditions – number greater than zero, lower then zero and equals to zero. Count the subarrays and divide by array length.

I created solution in 4 languages:

Scala
Java
JavaScript
Ruby

All solutions are also available on my GitHub.

Scala

import java.util.Locale

object PlusMinus extends App {
   val console = io.Source.stdin.bufferedReader()

   val n = console.readLine().toInt
   val arr = console.readLine().split(" ").map(_.toInt)

   println("%.3f".formatLocal(Locale.ENGLISH, arr.count(_ > 0) / n.toDouble))
   println("%.3f".formatLocal(Locale.ENGLISH, arr.count(_ < 0) / n.toDouble))
   println("%.3f".formatLocal(Locale.ENGLISH, arr.count(_ == 0) / n.toDouble))
}

import java.util.Locale

object PlusMinus extends App {

val console = io.Source.stdin.bufferedReader()

val n = console.readLine().toInt

val arr = console.readLine().split(" ").map(_.toInt)

println("%.3f".formatLocal(Locale.ENGLISH, arr.count(_ > 0) / n.toDouble))

println("%.3f".formatLocal(Locale.ENGLISH, arr.count(_ < 0) / n.toDouble))

println("%.3f".formatLocal(Locale.ENGLISH, arr.count(_ == 0) / n.toDouble))

}

Java

import java.util.*;

public class PlusMinus {
    public static void main(String[] args) {
        Scanner stdin = new Scanner(System.in);
        int n = Integer.parseInt(stdin.nextLine());
        String[] numbers = stdin.nextLine().split(" ");
        int positives = 0;
        int negatives = 0;
        int zeroes = 0;
        for(int i = 0; i < n; i++)
        {
            int num = Integer.parseInt(numbers[i]);
            if(num > 0)
            {
                positives++;    
            }
            else if(num < 0)
            {
                negatives++;
            }
            else
            {
                zeroes++;    
            }
        }
        System.out.println(String.format(Locale.ENGLISH, "%.3f", (double) positives / n));
        System.out.println(String.format(Locale.ENGLISH, "%.3f", (double) negatives / n));
        System.out.println(String.format(Locale.ENGLISH, "%.3f", (double) zeroes / n));
        stdin.close();
    }
}

import java.util.*;

public class PlusMinus {

public static void main(String[] args) {

Scanner stdin = new Scanner(System.in);

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

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

int positives = 0;

int negatives = 0;

int zeroes = 0;

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

{

int num = Integer.parseInt(numbers[i]);

if(num > 0)

{

positives++;

}

else if(num < 0)

{

negatives++;

}

else

{

zeroes++;

}

System.out.println(String.format(Locale.ENGLISH, "%.3f", (double) positives / n));

System.out.println(String.format(Locale.ENGLISH, "%.3f", (double) negatives / n));

System.out.println(String.format(Locale.ENGLISH, "%.3f", (double) zeroes / n));

stdin.close();

}

JavaScript

function processData(input) {
    var lines = input.split(" ");

    var n = parseInt(lines[0]);
    var arr = lines[1].split(" ").map(function(s) {return parseInt(s);});

    var positives = 0;
    var negatives = 0;
    var zeroes = 0;
    for(var i = 0; i < arr.length; i++)
    {
        if(arr[i] > 0)
        {
            positives++;
        }
        else if(arr[i] < 0)
        {
            negatives++;
        }
        else
        {
            zeroes++;
        }
    }
    console.log(positives / n);
    console.log(negatives / n);
    console.log(zeroes / n);
}

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(" ");

var n = parseInt(lines[0]);

var arr = lines[1].split(" ").map(function(s) {return parseInt(s);});

var positives = 0;

var negatives = 0;

var zeroes = 0;

for(var i = 0; i < arr.length; i++)

{

if(arr[i] > 0)

{

positives++;

}

else if(arr[i] < 0)

{

negatives++;

}

else

{

zeroes++;

}

console.log(positives / n);

console.log(negatives / n);

console.log(zeroes / n);

}

process.stdin.resume();

process.stdin.setEncoding("ascii");

_input = "";

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

_input += input;

});

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

processData(_input);

});

Ruby

n = gets.to_s.to_i
arr = gets.to_s.split(" ").map { |s| s.to_i }
positives = 0
negatives = 0
zeroes = 0
for i in arr do
  positives += 1 if i > 0
  negatives += 1 if i < 0
  zeroes += 1 if i == 0
end

puts positives / n.to_f
puts negatives / n.to_f
puts zeroes / n.to_f

n = gets.to_s.to_i

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

positives = 0

negatives = 0

zeroes = 0

for i in arr do

positives += 1 if i > 0

negatives += 1 if i < 0

zeroes += 1 if i == 0

end

puts positives / n.to_f

puts negatives / n.to_f

puts zeroes / n.to_f

Pavol Pidanič

I can count to 1023 with 10 fingers

Hackerrank – Plus Minus