Minimum Distances - Ruby - HackerRank

minimum_distances.rb

#!/bin/ruby

require 'json'
require 'stringio'

#
# Complete the 'minimumDistances' function below.
#
# The function is expected to return an INTEGER.
# The function accepts INTEGER_ARRAY a as parameter.
#

def minimumDistances(arr)
  # Write your code here
  min_distance = -1
  pairs = {}

  #find pairs - O(n)
  arr.each_with_index do |a, i|
    if pairs[a]
      current_distance = i - pairs[a][0]     
      min_distance = min_distance == -1 ? current_distance : [min_distance, current_distance].min
      pairs[a] << i
    else
      pairs[a] = [i]
    end
  end
  min_distance
end

fptr = File.open(ENV['OUTPUT_PATH'], 'w')

n = gets.strip.to_i

a = gets.rstrip.split.map(&:to_i)

result = minimumDistances a

fptr.write result
fptr.write "\n"

fptr.close()