January 2016 - Page 2 of 8

Hackerrank – Prefix Compression

Problem Statement A description of the problem can be found on Hackerrank. Solution Compare all characters from both string at the same index until they are not equals or we get to the end of one of strings. Equals characters are desired prefix. I created solution in: Scala All solutions are also available on my […]

Hackerrank – Picking Cards

Problem Statement A description of the problem can be found on Hackerrank. Solution Sort the array descending. Take N from the input. For each element e substract N – e. That means that there is only N – e combinations to choose these two cards. After substraction decrement N and select the next element. All […]

Hackerrank – Pangrams

Problem Statement A description of the problem can be found on Hackerrank. Solution Calculate if an input contains 26 distinct characters. I created solution in: Java JavaScript Ruby Scala All solutions are also available on my GitHub. Java

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;


public class Pangrams 
{
    public static void main(String[] args)
    {
        Scanner stdin = new Scanner(System.in);
        String string = stdin.nextLine().toLowerCase();
        Set<Character> alphabet = new HashSet<>();
        for(int i = 0; i < string.length(); i++)
        {
            if(string.charAt(i) != ' ')
            {
                alphabet.add(string.charAt(i));
            }
        }
        
        if(alphabet.size() == 26)
        {
            System.out.println("pangram");
        }
        else 
        {
            System.out.println("not pangram");
        }
        stdin.close();
    }
}

import java.util.HashSet;

import java.util.Scanner;

import java.util.Set;

public class Pangrams

{

public static void main(String[] args)

{

Scanner stdin = new Scanner(System.in);

String string = stdin.nextLine().toLowerCase();

Set<Character> alphabet = new HashSet<>();

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

{

if(string.charAt(i) != ' ')

{

alphabet.add(string.charAt(i));

}

if(alphabet.size() == 26)

{

System.out.println("pangram");

}

else

{

System.out.println("not pangram");

}

stdin.close();

}

JavaScript

function processData(input) {
    var hash = {};
    input = input.toLowerCase().replace(/\s+/g, '');
    for(var i = 0; i < input.length; i++) {
        hash[input[i]] = true;
    }

    if(isPangram(hash)) {
        console.log("pangram");
    } else {
        console.log("not pangram");
    }
}

function isPangram(hash) {
    var chars = 0;
    for(prop in hash) {
        if(hash.hasOwnProperty(prop)) {
            chars++;
        }
    }
    return chars === 26;
}

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 hash = {};

input = input.toLowerCase().replace(/\s+/g, '');

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

hash[input[i]] = true;

}

if(isPangram(hash)) {

console.log("pangram");

} else {

console.log("not pangram");

}

function isPangram(hash) {

var chars = 0;

for(prop in hash) {

if(hash.hasOwnProperty(prop)) {

chars++;

}

return chars === 26;

}

process.stdin.resume();

process.stdin.setEncoding("ascii");

_input = "";

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

_input += input;

});

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

processData(_input);

});

Ruby

require 'set'

s = Set.new(gets.downcase.gsub(/\s+/, "").chars())
if(s.size() == 26)
  puts "pangram"
else
  puts "not pangram"
end

require 'set'

s = Set.new(gets.downcase.gsub(/\s+/, "").chars())

if(s.size() == 26)

puts "pangram"

else

puts "not pangram"

end

Scala

import scala.io.Source

object Pangrams extends App {
  println(
    if(Source.stdin.bufferedReader().readLine().toLowerCase().distinct.replaceAll("\\s+", "").distinct.length == 26)
      "pangram"
    else
      "not pangram"
  )
}

import scala.io.Source

object Pangrams extends App {

println(

if(Source.stdin.bufferedReader().readLine().toLowerCase().distinct.replaceAll("\\s+", "").distinct.length == 26)

"pangram"

else

"not pangram"

)

}

Hackerrank – Pairs

Problem Statement A description of the problem can be found on Hackerrank. Solution Sort the array. Choose one element and check continously every next element after chosen element if their difference is equals to k. If it is greater stop comparisons and choose next element. Note: JavaScript and Ruby solutions use the same algorithm as […]

Hackerrank – Missing Numbers

Problem Statement A description of the problem can be found on Hackerrank. Solution Calculate count of every number in array A and B. Check every number count from B if it is in the array A or its count is lower than the count of the number in the array A. I created solution in: […]

Hackerrank – Minimum Draws

Problem Statement A description of the problem can be found on Hackerrank. Solution Minimum result if always greater then a given count of pairs. I created solution in: Java JavaScript Scala Ruby All solutions are also available on my GitHub. Java

import java.util.*;

public class MinimumDraws {

    public static void main(String[] args) {
        Scanner stdin = new Scanner(System.in);
        int tests = stdin.nextInt();
        for(int i = 0; i < tests; i++) {
            System.out.println(stdin.nextInt() + 1);
        }
        stdin.close();
    }
}

import java.util.*;

public class MinimumDraws {

public static void main(String[] args) {

Scanner stdin = new Scanner(System.in);

int tests = stdin.nextInt();

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

System.out.println(stdin.nextInt() + 1);

}

stdin.close();

}

JavaScript

'use strict';

const processData = input => {
    console.log(input.split('\n').slice(1).map(i => parseInt(i) + 1).join('\n'));
};

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 => {

console.log(input.split('\n').slice(1).map(i => parseInt(i) + 1).join('\n'));

};

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 MinimumDraws extends App {
  val lines = Source.stdin.getLines()
  val pairs = lines.drop(1).map(_.toInt)
  val draws = pairs.map(_ + 1)
  println(draws.mkString("\n"))
}

import scala.io.Source

object MinimumDraws extends App {

val lines = Source.stdin.getLines()

val pairs = lines.drop(1).map(_.toInt)

val draws = pairs.map(_ + 1)

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

}

Ruby

tests = gets.chomp.to_i
tests.times do
    pairs = gets.chomp.to_i
    result = pairs + 1
    puts result
end

tests = gets.chomp.to_i

tests.times do

pairs = gets.chomp.to_i

result = pairs + 1

puts result

end

Hackerrank – Maximizing XOR

Problem Statement A description of the problem can be found on Hackerrank. Solution Create all pairs for all numbers in interval [l, r]. XOR each pair and select maximum. I created solution in: Java JavaScript Scala Ruby All solutions are also available on my GitHub. Java

import java.util.*;

public class MaximizingXor {

    public static void main(String[] args) {
        Scanner stdin = new Scanner(System.in);
        int l = stdin.nextInt();
        int r = stdin.nextInt();
        int max = 0;
        for(int i = l; i <= r; i++) {
            for(int j = l; j <= r; j++) {
                int xor = i ^ j;
                if(xor > max) {
                    max = xor;
                }
            }
        }
        System.out.println(max);
        stdin.close();
    }
}

import java.util.*;

public class MaximizingXor {

public static void main(String[] args) {

Scanner stdin = new Scanner(System.in);

int l = stdin.nextInt();

int r = stdin.nextInt();

int max = 0;

for(int i = l; i <= r; i++) {

for(int j = l; j <= r; j++) {

int xor = i ^ j;

if(xor > max) {

max = xor;

}

System.out.println(max);

stdin.close();

}

JavaScript

function processData(input) {
    var l = parseInt(input.split("\n")[0]);
    var r = parseInt(input.split("\n")[1]);
    var max = 0;
    for(var i = l; i <= r; i++) {
        for(var j = l; j <= r; j++) {
            var xor = i ^ j;
            if(xor > max) {
                max = xor;
            }
        }
    }
    console.log(max);
}

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 l = parseInt(input.split("\n")[0]);

var r = parseInt(input.split("\n")[1]);

var max = 0;

for(var i = l; i <= r; i++) {

for(var j = l; j <= r; j++) {

var xor = i ^ j;

if(xor > max) {

max = xor;

}

console.log(max);

}

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 MaximizingXor extends App {
  val lines = Source.stdin.getLines().toList
  val l = lines(0).toInt
  val r = lines(1).toInt
  val maxXor = (l: Int, r: Int) => {
    var max = 0
    (l to r).foreach(
      i => {
        (l to r).foreach(
          j => {
            val xor = i ^ j
            if (xor > max) max = xor
          })
      }
    )
    max
  }

  println(maxXor(l, r))
}

import scala.io.Source

object MaximizingXor extends App {

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

val l = lines(0).toInt

val r = lines(1).toInt

val maxXor = (l: Int, r: Int) => {

var max = 0

(l to r).foreach(

i => {

(l to r).foreach(

j => {

val xor = i ^ j

if (xor > max) max = xor

})

}

)

max

}

println(maxXor(l, r))

}

Ruby

def maxXor(l, r)
  max = 0
  for i in l..r do
    for j in l..r do
      xor = i ^ j
      max = xor if xor > max
    end
  end
  return max
end


l = gets.to_i
r = gets.to_i
print maxXor(l, r)

def maxXor(l, r)

max = 0

for i in l..r do

for j in l..r do

xor = i ^ j

max = xor if xor > max

end

return max

end

l = gets.to_i

r = gets.to_i

print maxXor(l, r)

Hackerrank – Max Min

Problem Statement A description of the problem can be found on Hackerrank. Solution Sort the given array ascending. Make k parts of the array. Calculate unfairness as difference between last element and first element for all k subarrays. Select the minimum unfairness. Formerly it was called Angry Children. I created solution in: Ruby Java JavaScript […]

Hackerrank – Manasa and Stones

Problem Statement A description of the problem can be found on Hackerrank. Solution The result is set of leaves of a tree in depth n with a stating root 0 and every child is calculated as: parent + a and parent + b. I created solution in: Java JavaScript Scala Ruby All solutions are also […]

Hackerrank – Lonely Integer

Problem Statement A description of the problem can be found on Hackerrank. Solution Find counts of all elements with the same value and print only these that their count is equals to 1. I created solution in: Java JavaScript Scala Ruby All solutions are also available on my GitHub. Java

import java.util.*;

public class LonelyInteger {

    public static void main(String[] args) {
        Scanner stdin = new Scanner(System.in);
        int n = stdin.nextInt();
        Map<Integer, Integer> array = new HashMap<>();
        for(int i = 0; i < n; i++) {
            int num = stdin.nextInt();
            Integer count = array.get(num);
            if(count == null) {
                array.put(num, 1);
            } else {
                array.put(num, count + 1);
            }
        }
        for(Integer key : array.keySet()) {
            if(array.get(key) == 1) {
                System.out.println(key);
                break;
            }
        }

        stdin.close();
    }
}

import java.util.*;

public class LonelyInteger {

public static void main(String[] args) {

Scanner stdin = new Scanner(System.in);

int n = stdin.nextInt();

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

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

int num = stdin.nextInt();

Integer count = array.get(num);

if(count == null) {

array.put(num, 1);

} else {

array.put(num, count + 1);

}

for(Integer key : array.keySet()) {

if(array.get(key) == 1) {

System.out.println(key);

break;

}

stdin.close();

}

JavaScript

function processData(input) {
    var arr = input.split("\n")[1].split(" ").map(function(item) {return parseInt(item)});
    var hash = {};
    for(var i = 0; i < arr.length; i++) {
        if(hash[arr[i]]) {
            hash[arr[i]] += 1;
        } else {
            hash[arr[i]] = 1;
        }
    }
    for(prop in hash) {
        if(hash.hasOwnProperty(prop) && hash[prop] == 1) {
            console.log(prop);
            return;
        }
    }
}

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 arr = input.split("\n")[1].split(" ").map(function(item) {return parseInt(item)});

var hash = {};

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

if(hash[arr[i]]) {

hash[arr[i]] += 1;

} else {

hash[arr[i]] = 1;

}

for(prop in hash) {

if(hash.hasOwnProperty(prop) && hash[prop] == 1) {

console.log(prop);

return;

}

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 LonelyInteger extends App {
  val arr = (Source.stdin.getLines().toList)(1).split(" ").map(_.toInt)
  val groups = arr.groupBy(i => i)
  val uniqueElement = groups.keys.find(key => groups.get(key).get.size == 1)
  println(uniqueElement)
}

import scala.io.Source

object LonelyInteger extends App {

val arr = (Source.stdin.getLines().toList)(1).split(" ").map(_.toInt)

val groups = arr.groupBy(i => i)

val uniqueElement = groups.keys.find(key => groups.get(key).get.size == 1)

println(uniqueElement)

}

[…]

Pavol Pidanič

I can count to 1023 with 10 fingers

Month: January 2016

Hackerrank – Prefix Compression

Hackerrank – Picking Cards

Hackerrank – Pangrams

Hackerrank – Pairs

Hackerrank – Missing Numbers

Hackerrank – Minimum Draws

Hackerrank – Maximizing XOR

Hackerrank – Max Min

Hackerrank – Manasa and Stones

Hackerrank – Lonely Integer