Hackerrank - Beautiful Days at the Movies

Hackerrank – Problem Statement

A description of the problem can be found on Hackerrank.

Solution

For each number in the given interval between i and j count the numbers with valid given condition.

I created solution in:

Scala
Java
JavaScript
Ruby

All solutions are also available on my GitHub.

Java

import java.util.*;

public class Solution {

    public static void main(String[] args) {
        Scanner stdin = new Scanner(System.in);
        int start = stdin.nextInt();
        int end = stdin.nextInt();
        int k = stdin.nextInt();
        int count = 0;
        for(int i = start; i <= end; i++) {
            String s = String.valueOf(i);
            String reversed = new StringBuilder(s).reverse().toString();
            int diff = Math.abs(Integer.parseInt(s) - Integer.parseInt(reversed));
            if(diff % k == 0) {
                count++;
            }
        }
        System.out.println(count);
        stdin.close();
    }
}

import java.util.*;

public class Solution {

public static void main(String[] args) {

Scanner stdin = new Scanner(System.in);

int start = stdin.nextInt();

int end = stdin.nextInt();

int k = stdin.nextInt();

int count = 0;

for(int i = start; i <= end; i++) {

String s = String.valueOf(i);

String reversed = new StringBuilder(s).reverse().toString();

int diff = Math.abs(Integer.parseInt(s) - Integer.parseInt(reversed));

if(diff % k == 0) {

count++;

}

System.out.println(count);

stdin.close();

}

JavaScript

'use strict';

const reverse = (s) => s.split("").reverse().join("");

const processData = input => {
    const [start, end, d] = input.split(' ').map(i => parseInt(i));
    let count = 0;
    for(let i = start; i <= end; i++) {
        const s = i.toString();
        const reversed = reverse(s);
        const diff = Math.abs(parseInt(s) - parseInt(reversed));
        if(diff % d == 0) {
            count++;
        }
    }
    console.log(count);
};

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 reverse = (s) => s.split("").reverse().join("");

const processData = input => {

const [start, end, d] = input.split(' ').map(i => parseInt(i));

let count = 0;

for(let i = start; i <= end; i++) {

const s = i.toString();

const reversed = reverse(s);

const diff = Math.abs(parseInt(s) - parseInt(reversed));

if(diff % d == 0) {

count++;

}

console.log(count);

};

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 BeautifulDaysAtTheMovies extends App {
  val nums = Source.stdin.bufferedReader().readLine().split(" ").map(_.toInt)
  val start = nums(0)
  val end = nums(1)
  val d = nums(2)

  val beautifulNum = (start to end).count(num => {
    val reversed = num.toString.reverse.toInt
    val diff = (num - reversed).abs
    diff % d == 0
  })

  println(beautifulNum)
}

import scala.io.Source

object BeautifulDaysAtTheMovies extends App {

val nums = Source.stdin.bufferedReader().readLine().split(" ").map(_.toInt)

val start = nums(0)

val end = nums(1)

val d = nums(2)

val beautifulNum = (start to end).count(num => {

val reversed = num.toString.reverse.toInt

val diff = (num - reversed).abs

diff % d == 0

})

println(beautifulNum)

}

Ruby

(s, e, d) = gets.strip.split.map(&:to_i)

count = 0
for i in s..e do
  reversed = i.to_s.reverse
  count += 1 if (i - reversed.to_i).abs % d == 0
end

puts count

(s, e, d) = gets.strip.split.map(&:to_i)

count = 0

for i in s..e do

reversed = i.to_s.reverse

count += 1 if (i - reversed.to_i).abs % d == 0

end

puts count

Pavol Pidanič

I can count to 1023 with 10 fingers

Hackerrank – Beautiful Days at the Movies