Archives Hackerrank - Page 3 of 26

Hackerrank – Birthday Cake Candles

Hackerrank – Problem Statement A description of the problem can be found on Hackerrank. Solution We find the highest candles. Then we find count of candles with max height. I created solution in: Scala Java JavaScript All solutions are also available on my GitHub profile. Scala

object BirthdayCakeCandles {

  def birthdayCakeCandles(n: Int, ar: Array[Int]): Int =  {
    val candleHeightGroups: Map[Int, Seq[Int]] = ar.toList.groupBy(i => i)
    val maxHeight = candleHeightGroups.keys.max
    candleHeightGroups.getOrElse(maxHeight, Seq.empty).size
  }

  def main(args: Array[String]) {
    val sc = new java.util.Scanner (System.in)
    val n = sc.nextInt()
    val ar = new Array[Int](n)
    for(ar_i <- 0 until n) {
      ar(ar_i) = sc.nextInt()
    }
    val result = birthdayCakeCandles(n, ar)
    println(result)
  }
}

object BirthdayCakeCandles {

def birthdayCakeCandles(n: Int, ar: Array[Int]): Int = {

val candleHeightGroups: Map[Int, Seq[Int]] = ar.toList.groupBy(i => i)

val maxHeight = candleHeightGroups.keys.max

candleHeightGroups.getOrElse(maxHeight, Seq.empty).size

}

def main(args: Array[String]) {

val sc = new java.util.Scanner (System.in)

val n = sc.nextInt()

val ar = new Array[Int](n)

for(ar_i <- 0 until n) {

ar(ar_i) = sc.nextInt()

}

val result = birthdayCakeCandles(n, ar)

println(result)

}

Java

import java.util.*;

public class BirthdayCakeCandles {

    static int birthdayCakeCandles(int n, int[] ar) {
        int max = 0;
        for(int i = 0; i < ar.length; i++) {
            if(ar[i] > max) {
                max = ar[i];
            }
        }
        int count = 0;
        for(int i = 0; i < ar.length; i++) {
            if(ar[i] == max) {
                count++;
            }
        }
        return count;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] ar = new int[n];
        for(int ar_i = 0; ar_i < n; ar_i++){
            ar[ar_i] = in.nextInt();
        }
        int result = birthdayCakeCandles(n, ar);
        System.out.println(result);
    }
}

import java.util.*;

public class BirthdayCakeCandles {

static int birthdayCakeCandles(int n, int[] ar) {

int max = 0;

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

if(ar[i] > max) {

max = ar[i];

}

int count = 0;

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

if(ar[i] == max) {

count++;

}

return count;

}

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

int n = in.nextInt();

int[] ar = new int[n];

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

ar[ar_i] = in.nextInt();

}

int result = birthdayCakeCandles(n, ar);

System.out.println(result);

}

Javascript

'use strict';

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

var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;

process.stdin.on('data', function (data) {
    input_stdin += data;
});

process.stdin.on('end', function () {
    input_stdin_array = input_stdin.split("\n");
    main();    
});

function readLine() {
    return input_stdin_array[input_currentline++];
}

/////////////// ignore above this line ////////////////////

function birthdayCakeCandles(n, ar) {
    let max = 0;
    for(let i = 0; i < ar.length; i++) {
        if(ar[i] > max) {
            max = ar[i];
        }
    }
    let count = 0;
    for(let i = 0; i < ar.length; i++) {
        if(ar[i] === max) {
            count++;
        }
    }
    return count;
}

function main() {
    var n = parseInt(readLine());

    const ar = readLine().split(' ').map(i => parseInt(i));
    var result = birthdayCakeCandles(n, ar);
    process.stdout.write("" + result + "\n");

}

'use strict';

process.stdin.resume();

process.stdin.setEncoding('ascii');

var input_stdin = "";

var input_stdin_array = "";

var input_currentline = 0;

process.stdin.on('data', function (data) {

input_stdin += data;

});

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

input_stdin_array = input_stdin.split("\n");

main();

});

function readLine() {

return input_stdin_array[input_currentline++];

}

/////////////// ignore above this line ////////////////////

function birthdayCakeCandles(n, ar) {

let max = 0;

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

if(ar[i] > max) {

max = ar[i];

}

let count = 0;

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

if(ar[i] === max) {

count++;

}

return count;

}

function main() {

var n = parseInt(readLine());

const ar = readLine().split(' ').map(i => parseInt(i));

var result = birthdayCakeCandles(n, ar);

process.stdout.write("" + result + "\n");

}

Hackerrank – Taum and B’day

Hackerrank – Problem Statement A description of the problem can be found on Hackerrank. Solution The hint is given in problem description. One should compare if it is better to buy presents without changing colors or with changing colors. I created solution in: Scala Java JavaScript All solutions are also available on my GitHub profile. […]

Hackerrank – Sequence Equation

Hackerrank – Problem Statement A description of the problem can be found on Hackerrank. Solution I have given count of numbers n. I will iterate over all numbers from 1 to n I will find index of each iterated number in all elements and then index of index within all elements I created solution in: […]

Hackerrank – Priyanka and Toys

Hackerrank – Problem Statement A description of the problem can be found on Hackerrank. Solution I created solution in: Scala Java JavaScript All solutions are also available on my GitHub profile. Scala

object PriyankaAndToys extends App {
  val lines = Source.stdin.getLines().toList
  val n = Integer.parseInt(lines.head)
  val weights = lines.tail.head.split("\\s+").map(_.toInt).sorted
  var price = 1
  var lastWeight = weights(0)

  var i = 1
  while ( {
    i < weights.length
  }) {
    if (lastWeight + 4 >= weights(i)) {
      // lastWeight = toys[i];
    }
    else {
      price += 1
      lastWeight = weights(i)
    }

    {
      i += 1; i - 1
    }
  }
  println(price)
}

object PriyankaAndToys extends App {

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

val n = Integer.parseInt(lines.head)

val weights = lines.tail.head.split("\\s+").map(_.toInt).sorted

var price = 1

var lastWeight = weights(0)

var i = 1

while ( {

i < weights.length

}) {

if (lastWeight + 4 >= weights(i)) {

// lastWeight = toys[i];

}

else {

price += 1

lastWeight = weights(i)

}

{

i += 1; i - 1

}

println(price)

}

Java

import java.util.Arrays;
import java.util.Scanner;

public class PriyankaAndToys
{
    public static void main(String[] args)
    {
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());
        String[] weights = scanner.nextLine().split("\\s+");

        int[] toyWeights = new int[n];
        for (int i = 0; i < n; i++)
        {
            toyWeights[i] = Integer.parseInt(weights[i]);
        }

        Arrays.sort(toyWeights);
        int price = 1;
        int lastWeight = toyWeights[0];

        for (int i = 1; i < toyWeights.length; i++)
        {
            if(lastWeight + 4 >= toyWeights[i])
            {
                // lastWeight = toys[i];
            }
            else
            {
                price++;
                lastWeight = toyWeights[i];
            }
        }
        System.out.println(price);
        scanner.close();
    }
}

import java.util.Arrays;

import java.util.Scanner;

public class PriyankaAndToys

{

public static void main(String[] args)

{

Scanner scanner = new Scanner(System.in);

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

String[] weights = scanner.nextLine().split("\\s+");

int[] toyWeights = new int[n];

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

{

toyWeights[i] = Integer.parseInt(weights[i]);

}

Arrays.sort(toyWeights);

int price = 1;

int lastWeight = toyWeights[0];

for (int i = 1; i < toyWeights.length; i++)

{

if(lastWeight + 4 >= toyWeights[i])

{

// lastWeight = toys[i];

}

else

{

price++;

lastWeight = toyWeights[i];

}

System.out.println(price);

scanner.close();

}

Javascript

'use strict';

const processData = input => {
    const lines = input.split('\n');
    const n = parseInt(lines[0]);
    const weights = lines[1].split(" ").map(i => parseInt(i)).sort((a, b) => a - b);

    let price = 1;
    let lastWeight = weights[0];
    for (let i = 1; i < weights.length; i++)
    {
        if(lastWeight + 4 >= weights[i])
        {
            // lastWeight = toys[i];
        }
        else
        {
            price++;
            lastWeight = weights[i];
        }
    }
    console.log(price);
};

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 n = parseInt(lines[0]);

const weights = lines[1].split(" ").map(i => parseInt(i)).sort((a, b) => a - b);

let price = 1;

let lastWeight = weights[0];

for (let i = 1; i < weights.length; i++)

{

if(lastWeight + 4 >= weights[i])

{

// lastWeight = toys[i];

}

else

{

price++;

lastWeight = weights[i];

}

console.log(price);

};

process.stdin.resume();

process.stdin.setEncoding("ascii");

let _input = "";

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

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

Hackerrank – Consecutive Subsequences

Hackerrank – Problem Statement A description of the problem can be found on Hackerrank. Solution http://stackoverflow.com/questions/24518682/count-subsequences-divisible-by-k I created solution in: Java All solutions are also available on my GitHub profile. Java

import java.util.Scanner;

// http://stackoverflow.com/questions/24518682/count-subsequences-divisible-by-k
public class ConsecutiveSubsequences
{
    public static void main(String[] args)
    {
        Scanner scanner = new Scanner(System.in);
        int tests = scanner.nextInt();

        for(int l = 0; l < tests; l++)
        {
            int n = scanner.nextInt();
            int k = scanner.nextInt();
            long[] numbers = new long[n];

            for(int i = 0; i < n; i++)
            {
                numbers[i] = scanner.nextLong();
            }

            long[] prefixModCount = new long[k];
            for(int i = 0; i < k; i++)
            {
                prefixModCount[i] = 0;
            }
            prefixModCount[0] = 1;

            int prefixSum = 0;
            for(int i = 0; i < numbers.length; i++)
            {
                prefixSum += numbers[i];
                prefixSum %= k;
                prefixModCount[prefixSum] += 1;
            }

            long result = 0;
            for(int mod = 0; mod < k; mod++)
            {
                result += prefixModCount[mod] * (prefixModCount[mod] - 1) / 2;
            }
            System.out.println(result);
        }

        scanner.close();
    }
}

import java.util.Scanner;

// http://stackoverflow.com/questions/24518682/count-subsequences-divisible-by-k

public class ConsecutiveSubsequences

{

public static void main(String[] args)

{

Scanner scanner = new Scanner(System.in);

int tests = scanner.nextInt();

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

{

int n = scanner.nextInt();

int k = scanner.nextInt();

long[] numbers = new long[n];

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

{

numbers[i] = scanner.nextLong();

}

long[] prefixModCount = new long[k];

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

{

prefixModCount[i] = 0;

}

prefixModCount[0] = 1;

int prefixSum = 0;

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

{

prefixSum += numbers[i];

prefixSum %= k;

prefixModCount[prefixSum] += 1;

}

long result = 0;

for(int mod = 0; mod < k; mod++)

{

result += prefixModCount[mod] * (prefixModCount[mod] - 1) / 2;

}

System.out.println(result);

}

scanner.close();

}

Hackerrank – Project Euler+ #067 – Maximum path sum II

Hackerrank – Problem description The problem description – Hackerrank. Solution The same solution as Maximum Path Sum I.

Hackerrank – Project Euler+ #036 – Double-base palindromes

Hackerrank – Problem description The problem description – Hackerrank. Solution Steps are given in the problem description. I created solution in: Java All solutions are also available on my GitHub profile. Java

public class DoubleBasePalindromes 
{
	public static void main(String[] args)
	{
		Scanner stdin = new Scanner(System.in);
		int n = stdin.nextInt();
		int base = stdin.nextInt();
		long sum = 0;
		for(int i = 1; i < n; i++)
		{
			String decimalString = Integer.toString(i, 10);
			String kBaseString = Integer.toString(i, base);
			if(isPalindrome(decimalString) && isPalindrome(kBaseString))
			{
				sum += i;
			}
		}
		System.out.println(sum);
		stdin.close();
	}
	
	
	private static boolean isPalindrome(String n)
	{
		for(int i = 0; i < n.length() / 2; i++)
		{
			char first = n.charAt(i);
			char last = n.charAt(n.length() - i - 1);
			if(first != last)
			{
				return false;
			}
		}
		return true;
	}
}

public class DoubleBasePalindromes

{

public static void main(String[] args)

{

Scanner stdin = new Scanner(System.in);

int n = stdin.nextInt();

int base = stdin.nextInt();

long sum = 0;

for(int i = 1; i < n; i++)

{

String decimalString = Integer.toString(i, 10);

String kBaseString = Integer.toString(i, base);

if(isPalindrome(decimalString) && isPalindrome(kBaseString))

{

sum += i;

}

System.out.println(sum);

stdin.close();

}

private static boolean isPalindrome(String n)

{

for(int i = 0; i < n.length() / 2; i++)

{

char first = n.charAt(i);

char last = n.charAt(n.length() - i - 1);

if(first != last)

{

return false;

}

return true;

}

Hackerrank – Project Euler+ #022 – Name scores

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;

public class NameScores
{
    private static Map<Character, Integer> alphabet;
    static
    {
        alphabet = new HashMap<>(26);
        alphabet.put('A', 1);
        alphabet.put('B', 2);
        alphabet.put('C', 3);
        alphabet.put('D', 4);
        alphabet.put('E', 5);
        alphabet.put('F', 6);
        alphabet.put('G', 7);
        alphabet.put('H', 8);
        alphabet.put('I', 9);
        alphabet.put('J', 10);
        alphabet.put('K', 11);
        alphabet.put('L', 12);
        alphabet.put('M', 13);
        alphabet.put('N', 14);
        alphabet.put('O', 15);
        alphabet.put('P', 16);
        alphabet.put('Q', 17);
        alphabet.put('R', 18);
        alphabet.put('S', 19);
        alphabet.put('T', 20);
        alphabet.put('U', 21);
        alphabet.put('V', 22);
        alphabet.put('W', 23);
        alphabet.put('X', 24);
        alphabet.put('Y', 25);
        alphabet.put('Z', 26);
    }

    public static void main(String[] args)
    {
        Scanner scanner = new Scanner(System.in);
        int namesCount = Integer.parseInt(scanner.nextLine());
        List<String> namesList = new ArrayList<>(namesCount);
        for (int i = 0; i < namesCount; i++)
        {
            String name = scanner.nextLine();
            namesList.add(name);
        }
        Collections.sort(namesList);
        Map<String, Integer> names = new HashMap<>();
        for (int i = 1; i <= namesList.size(); i++)
        {
            names.put(namesList.get(i - 1), i);
        }
        int queries = Integer.parseInt(scanner.nextLine());
        for (int i = 0; i < queries; i++)
        {
            String query = scanner.nextLine();
            int score = nameScore(names, query);
            System.out.println(score);
        }
        scanner.close();
    }

    private static int nameScore(Map<String, Integer> names, String name)
    {
        int result = 0;
        for (int i = 0; i < name.length(); i++)
        {
            result += alphabet.get(name.charAt(i));
        }
        result *= names.get(name);
        return result;
    }
}

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.Scanner;

public class NameScores

{

private static Map<Character, Integer> alphabet;

static

{

alphabet = new HashMap<>(26);

alphabet.put('A', 1);

alphabet.put('B', 2);

alphabet.put('C', 3);

alphabet.put('D', 4);

alphabet.put('E', 5);

alphabet.put('F', 6);

alphabet.put('G', 7);

alphabet.put('H', 8);

alphabet.put('I', 9);

alphabet.put('J', 10);

alphabet.put('K', 11);

alphabet.put('L', 12);

alphabet.put('M', 13);

alphabet.put('N', 14);

alphabet.put('O', 15);

alphabet.put('P', 16);

alphabet.put('Q', 17);

alphabet.put('R', 18);

alphabet.put('S', 19);

alphabet.put('T', 20);

alphabet.put('U', 21);

alphabet.put('V', 22);

alphabet.put('W', 23);

alphabet.put('X', 24);

alphabet.put('Y', 25);

alphabet.put('Z', 26);

}

public static void main(String[] args)

{

Scanner scanner = new Scanner(System.in);

int namesCount = Integer.parseInt(scanner.nextLine());

List<String> namesList = new ArrayList<>(namesCount);

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

{

String name = scanner.nextLine();

namesList.add(name);

}

Collections.sort(namesList);

Map<String, Integer> names = new HashMap<>();

for (int i = 1; i <= namesList.size(); i++)

{

names.put(namesList.get(i - 1), i);

}

int queries = Integer.parseInt(scanner.nextLine());

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

{

String query = scanner.nextLine();

int score = nameScore(names, query);

System.out.println(score);

}

scanner.close();

}

private static int nameScore(Map<String, Integer> names, String name)

{

int result = 0;

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

{

result += alphabet.get(name.charAt(i));

}

result *= names.get(name);

return result;

}

Hackerrank – Project Euler+ #020 – Factorial digit sum

Hackerrank – Problem description The problem description Hackerrank. Solution The catch is to have a support for big numbers operations in your progamming language. Do a factorial and sum the numbers. I created solution in: Ruby All solutions are also available on my GitHub profile. Ruby

def factorial(n)
  fact = 1
  for i in 2..n do
    fact *= i
  end
  return fact
end


def sum_digits(number)
  chars = number.to_s.chars
  sum = 0
  chars.each { |char| sum += char.to_i }
  return sum
end
 
gets.chomp.to_i.times do
  n = gets.chomp.to_i
  puts sum_digits(factorial(n))
end

def factorial(n)

fact = 1

for i in 2..n do

fact *= i

end

return fact

end

def sum_digits(number)

chars = number.to_s.chars

sum = 0

chars.each { |char| sum += char.to_i }

return sum

end

gets.chomp.to_i.times do

n = gets.chomp.to_i

puts sum_digits(factorial(n))

end

Hackerrank – Project Euler+ #019 – Counting Sundays

Hackerrank – Problem description The problem description – Hackerrank. Solution The implementation is specific based on a programming language – the features in libraries for date manipulation. I found out from given date, what is the next sunday. Then I added 7 days to the sunday’s date, to have next sunday. I was cautioned for […]

Pavol Pidanič

I can count to 1023 with 10 fingers

Category: Hackerrank

Hackerrank – Birthday Cake Candles

Hackerrank – Taum and B’day

Hackerrank – Sequence Equation

Hackerrank – Priyanka and Toys

Hackerrank – Consecutive Subsequences

Hackerrank – Project Euler+ #067 – Maximum path sum II

Hackerrank – Project Euler+ #036 – Double-base palindromes

Hackerrank – Project Euler+ #022 – Name scores

Hackerrank – Project Euler+ #020 – Factorial digit sum

Hackerrank – Project Euler+ #019 – Counting Sundays