Hackerrank - Minimum Distances

Hackerrank – Problem Statement

A description of the problem can be found on Hackerrank.

Solution

Create index pairs variations for all indexes that pair are unique – it means when (i, j) exists (j, i) is the same. Filter only this pairs of indexes, which have the same value. Make an absolute difference of them |i-j| and choose the minimum value. if there are not differences, print -1.

I created solution in:

Scala
Java
JavaScript
Ruby

All solutions are also available on my GitHub.

Java

import java.util.*;

public class MinimumDistances {

    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();
        }

        int min = Integer.MAX_VALUE;
        for(int i = 0; i < n - 1; i++) {
            for(int j = i + 1; j < n; j++) {
                if(array[i] == array[j]) {
                    min = Math.min(min, Math.abs(j - i));
                }
            }
        }
        int result = (min == Integer.MAX_VALUE ? -1 : min);
        System.out.println(result);
        stdin.close();
    }
}

import java.util.*;

public class MinimumDistances {

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();

}

int min = Integer.MAX_VALUE;

for(int i = 0; i < n - 1; i++) {

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

if(array[i] == array[j]) {

min = Math.min(min, Math.abs(j - i));

}

int result = (min == Integer.MAX_VALUE ? -1 : min);

System.out.println(result);

stdin.close();

}

JavaScript

'use strict';

const processData = input => {
    const lines = input.split('\n');
    const array = lines[1].split(' ').map(i => parseInt(i));

    let min = 999999999;
    for(let i = 0; i < array.length - 1; i++) {
        for(let j = i + 1; j < array.length; j++) {
            if(array[i] == array[j]) {
                min = Math.min(min, Math.abs(j - i));
            }
        }
    }
    const result = (min === 999999999 ? -1 : min);
    console.log(result);
};

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(' ').map(i => parseInt(i));

let min = 999999999;

for(let i = 0; i < array.length - 1; i++) {

for(let j = i + 1; j < array.length; j++) {

if(array[i] == array[j]) {

min = Math.min(min, Math.abs(j - i));

}

const result = (min === 999999999 ? -1 : min);

console.log(result);

};

process.stdin.resume();

process.stdin.setEncoding("ascii");

let _input = "";

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

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

Scala

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

  val indexPairs = array.indices.flatMap(i => array.indices.slice(i + 1, array.length).map(j => (i, j)))
  val equalValues = indexPairs.filter(pair => array(pair._1) == array(pair._2))
  val distances = equalValues.map(pair => (pair._1 - pair._2).abs)

  val result = if(distances.isEmpty) -1 else distances.min
  println(result)
}

object MinimumDistances extends App {

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

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

val indexPairs = array.indices.flatMap(i => array.indices.slice(i + 1, array.length).map(j => (i, j)))

val equalValues = indexPairs.filter(pair => array(pair._1) == array(pair._2))

val distances = equalValues.map(pair => (pair._1 - pair._2).abs)

val result = if(distances.isEmpty) -1 else distances.min

println(result)

}

Ruby

n = gets.to_i
arr = gets.split(" ").map {|i| i.to_i}
min = 99999999
for i in 0..(n-1)
  for j in (i+1)..n
    min = [min, (j - i).abs].min if (arr[j] == arr[i])
  end
end

min = -1 if(min == 99999999)
puts min

n = gets.to_i

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

min = 99999999

for i in 0..(n-1)

for j in (i+1)..n

min = [min, (j - i).abs].min if (arr[j] == arr[i])

end

min = -1 if(min == 99999999)

puts min

Pavol Pidanič

I can count to 1023 with 10 fingers

Hackerrank – Minimum Distances