<![CDATA[
#!/usr/bin/perl -w
use strict;
use diagnostics;
package main; # default namespace
my @examples = ("macecad",
"Racecar",
"Go hang a salami; I'm a lasagna hog!",
"Mississippi",
"Are we not drawn onward, we few, drawn onward to new era?",
"Madam, I'm Adam.",
"Able was I ere I saw Elba.");
print "\n";
foreach my $example(@examples) {
my $output = $example . "\nThis";
if ( isPalindrome($example) ) {
$output = $output . " is ";
} else {
$output = $output . " is not ";
}
$output = $output . "a palindrome.\n\n";
print $output;
}
exit(0);
# if ( isPalindrome($example) )
sub isPalindrome {
my $example = shift;
$example = makeTextOnly($example);
my $length = length($example);
my $i = 0;
my $j = $length - 1;
# check equality of first & last characters
# Else, complete and return "true"
while ($i < $j) {
# Exit at the first mismatch, returning "false"
if (!(substr($example, $i, 1) eq substr($example, $j, 1))) {
return 0;
}
++ $i;
-- $j;
}
return 1;
}
# $text = makeTextOnly($example);
sub makeTextOnly {
my $example = shift;
# Make case-insensitive (all uppercase)
$example = uc($example);
# Remove whitespaces
$example =~ s/\s//g;
# Remove punctuation
$example =~ s/[?;:!,.'"]//g;
return $example;
}
]]>