An example of an algorithm to generate permutations.

 FirstPermute.pl            a terse version : not the recommended style
                             * no documentation
			     * no tests
			     * command line switches using -s
			     * Use: ./FirstPermute.pl -n=5 -times=2 -quiet

 time_first                 a bash script to run FirstPermute.pl and get run times
 time_first.out             output of time_first, hand edited for input to gnuplot
 plot_first                 gnuplot script; input=time_first.out, output=first.png
 first.png                  png image of FirstPermute.pl run times

 SecondPermute.pm           a cleaner version : better interface, docs, tests, timing
 SecondPermute.out          output from "perl SecondPermute.pm"

 sample_plot/plot           an example of a script to run gnuplot
 sample_plot/data           example input data for sample_plot/plot
 sample_plot/file.png       the output picture produced by sample_plot/plot