#!/usr/local/bin/perl
#################################################
# hanoi.pl
# translated from C++ to Perl by Jeff Anderson
# original C++ code by Brenda Parker
#################################################
#recursive function
sub Hanoi {
local($number, $from, $to, $aux);
($number, $from, $to, $aux) = @_;
if ($number == 1) {
print "Move 1 from $from to $to
";
}
elsif ($number != 0) {
&Hanoi($number-1,$from,$aux,$to);
print "Move $number from $from to $to
";
&Hanoi($number-1,$aux,$to,$from);
}
}
#this library contains the function &GetFormInput which reads
#and parses the form data
require('libs/forms-lib.pl');
#read input from the form
%input = &GetFormInput();
print "Content-type: text/html\n\n";
$number = $input{'pegs'};
unless ($number =~ /^[0-1]?[0-9]$/) {
print "Numeric, not alpha-numeric!
";
exit;
}
print <<"EOM";
Towers Result
EOM
if ($number < 1) {
print "You are really cruel, zero pegs. Go away.
";
} elsif ($number > 15) {
print "I said 15 is the max, go tie up your own processor!
";
} else {
print "For $number pegs:";
&Hanoi($number,'A','B','C');
}
print <<"EOM";
EOM