#!/usr/bin/env ruby
# Copyright 2005 Daniel Cer (daniel.cer@cs.colorado.edu)
#
# This work is licensed under the Creative Commons Attribution-NonCommercial-
# ShareAlike License. To view a copy of this license, visit 
# http://creativecommons.org/licenses/by-nc-sa/2.5/ or send a letter to 
# Creative Commons, 543 Howard Street, 5th Floor, San Francisco, California, 
# 94105, USA.

# insertion_sort - sort, in place, the list given by 'entries'
# As a convenience, the list 'entries' is also returned by this function
def insertion_sort(entries) 
  e = entries # shortened alias for list given by 'entries'
  1.upto(e.length-1) do |i| j = nil; value = e[i]
    if (i-1).downto(0) { |j| break if (e[j] <= value); e[j+1] = e[j] } then
      e[0] = value   # place 'value' at the very begining of the sorted list
    else 
      e[j+1] = value # place 'value' just after the entry at position 'j' 
  end; end; entries
end

if ARGV.length != 1
  $stderr.puts "Usage:\n\t#{$0} (file with numbers to sort)"
  exit -1
end

# read in the entries
entries = Array.new; IO.foreach(ARGV[0]) { |line| entries.push Float(line) }

# sort the entries & the display the sorted results
insertion_sort(entries).each { |line| puts line }