Hackerrank - Equalize the Array

Hackerrank – Problem Statement

A description of the problem can be found on Hackerrank.

Solution

Create groups containing same numbers from defined array. The result is length of the array without size of the biggest groups.

Explanation: The only way to make a minimum deletion of other numbers from array. If I would delete any group which does not have the biggest count of elements, number of deletion would be always more.

I created solution in:

Scala
Java
JavaScript
Ruby

All solutions are also available on my GitHub.

Java

import java.util.*;

public class EqualizeTheArray {

    public static void main(String[] args) {
        Scanner stdin = new Scanner(System.in);
        int n = stdin.nextInt();
        int[] array = new int[n];
        for(int i = 0; i < n; i++) {
            array[i] = stdin.nextInt();
        }
        Map<Integer, Integer> numCount = new HashMap<>();
        for(int i = 0; i < n; i++) {
            int count = numCount.getOrDefault(array[i], 0);
            numCount.put(array[i], count + 1);
        }
        int maxCount = numCount.values().stream().max(
                (Integer o1, Integer o2) -> o1 - o2
        ).orElse(0);

        System.out.println(n - maxCount);
        stdin.close();
    }
}

import java.util.*;

public class EqualizeTheArray {

public static void main(String[] args) {

Scanner stdin = new Scanner(System.in);

int n = stdin.nextInt();

int[] array = new int[n];

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

array[i] = stdin.nextInt();

}

Map<Integer, Integer> numCount = new HashMap<>();

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

int count = numCount.getOrDefault(array[i], 0);

numCount.put(array[i], count + 1);

}

int maxCount = numCount.values().stream().max(

(Integer o1, Integer o2) -> o1 - o2

).orElse(0);

System.out.println(n - maxCount);

stdin.close();

}

JavaScript

'use strict';

const processData = input => {
    const lines = input.split('\n');
    const array = lines[1].split(' ');
    const numCounts = {};
    for(let i = 0; i < array.length; i++) {
        let count = numCounts[array[i]] || 0;
        numCounts[array[i]] = count + 1;
    }
    let maxCount = 0;
    for(let p in numCounts) {
        if(numCounts.hasOwnProperty(p) && numCounts[p] > maxCount) {
            maxCount = numCounts[p];
        }
    }
    console.log(array.length - maxCount);
};

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

let _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 array = lines[1].split(' ');

const numCounts = {};

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

let count = numCounts[array[i]] || 0;

numCounts[array[i]] = count + 1;

}

let maxCount = 0;

for(let p in numCounts) {

if(numCounts.hasOwnProperty(p) && numCounts[p] > maxCount) {

maxCount = numCounts[p];

}

console.log(array.length - maxCount);

};

process.stdin.resume();

process.stdin.setEncoding("ascii");

let _input = "";

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

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

Scala

import scala.io.Source

object EqualizeTheArray extends App {
  val lines = Source.stdin.getLines().toList
  val array = lines(1).split(" ").map(_.toInt)

  val maxOccuredNumber = array.groupBy(n => n).map(_._2.length).max
  val toRemove = array.length - maxOccuredNumber
  println(toRemove)
}

import scala.io.Source

object EqualizeTheArray extends App {

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

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

val maxOccuredNumber = array.groupBy(n => n).map(_._2.length).max

val toRemove = array.length - maxOccuredNumber

println(toRemove)

}

Ruby

n = gets.strip.to_i
arr = gets.strip.split

num_counts = Hash.new
arr.each do |num|
  count = 0
    count = num_counts[num] if num_counts.has_key?(num)
  num_counts[num] = count + 1
end

max_count = 0
num_counts.each_key do |key|
  count = num_counts[key]
  max_count = count if count > max_count
end

puts n - max_count

n = gets.strip.to_i

arr = gets.strip.split

num_counts = Hash.new

arr.each do |num|

count = 0

count = num_counts[num] if num_counts.has_key?(num)

num_counts[num] = count + 1

end

max_count = 0

num_counts.each_key do |key|

count = num_counts[key]

max_count = count if count > max_count

end

puts n - max_count

Pavol Pidanič

I can count to 1023 with 10 fingers

Hackerrank – Equalize the Array