next_larget_number

def find_next_largest arr
  base = arr[0]
  new_base = arr.map{|x| x if x > base}.compact.sort.first

  new_array = [new_base]
  no_of_times_base_value_present = arr.select{|x| x == new_base}.compact.count

  rest_array = arr - [new_base] + (new_base.to_s*(no_of_times_base_value_present-1)).split("").map{|x| x.to_i}
  rest_array = rest_array.sort

  new_array << rest_array
  new_array.flatten
end

num =  134466530

puts "input : #{num}"

numbers_array = num.to_s.split('').map{|x| x.to_i}
reverse_array = numbers_array.reverse

puts "arr : #{numbers_array}"

reverse_array.reverse.each_with_index do |x, i |
  sub_string = reverse_array[0, i].reverse

  next if  sub_string == sub_string.sort.reverse
  string_to_replace =  sub_string.join('')
  puts "STRING TO REPLACE"
  puts string_to_replace
  puts "=================="

  new_string =  find_next_largest(sub_string).join('')

  puts "NEW STRING"
  puts new_string
  puts "=================="

  puts "ANSWER : "
  puts num.to_s.gsub(string_to_replace, new_string)
  puts "--------------------"

  break

end