task6.rb

class Road < Object
  attr_accessor :low_bound,
                :high_bound,
                :transport_count,
                :road_id,
                :counter

end

file = File.open('F:/input.txt', 'r')
i = 0

road_count = file.readline.to_i;
arr = Array.new

r = nil

for i in (1..road_count)
  line = file.readline.to_s
  r = Road.new()
  r.road_id = i
  bound_arr = line.to_s.split(' ')
  r.low_bound = bound_arr[0]
  r.high_bound = bound_arr[1]
  arr << r
end

file.readline();
transp_str = file.readline().to_s + ' ';

start_pos = 0;

while start_pos < transp_str.length
  # например, так
  r.counter += 1
  arr[transp_str[start_pos..transp_str.index(' ', start_pos)].to_i].transport_count += 1
  start_pos = transp_str.index(' ', start_pos) + 1
end