sub findInterleavedString {
	my $string=$_[0];
	my $word=$_[1];
	my @letters=split //,$word;

	my $index=0;
	for(my $i=0;$i<=$#letters && $index!=-1;++$i) {
		$index=index $string, $letters[$i], $index+1;
	}
	return $index!=-1;
}

##</code><code>##

#!/usr/bin/perl -w

use strict;

use Benchmark qw(cmpthese);

{
	my $word="sigma";
	my $re  = join '.*?',
			  map quotemeta,
			  split (//,$word);

	sub ikegami {
		my $result=1;
		foreach my $text (
			'sigma',
			'stigma',
			'magma',
		) {
			$result &&= ($text=~$re);
		}
	}
}

sub ikegami_noprep {
	my $word="sigma";
	my $re  = join '.*?',
			  map quotemeta,
			  split (//,$word);
	my $result=1;
	foreach my $text (
		'sigma',
		'stigma',
		'magma',
	) {
		$result &&= ($text=~$re);
	}
}

{
	my $word='sigma';
	my @letters=split //,$word;
	sub findSigma {
		my $string=$_[0];
		my $index=0;
		for(my $i=0;$i<=$#letters && $index!=-1;++$i) {
			$index=index $string, $letters[$i], $index+1;
		}
		return $index!=-1;
	}
	sub rmgir {
		my $result=1;
		foreach my $text (
			'sigma',
			'stigma',
			'magma',
		) {
			$result &&= findSigma($text);
		}
	}
}

sub findInterleavedString {
	my $string=$_[0];
	my $word=$_[1];
	my @letters=split //,$word;

	my $index=0;
	for(my $i=0;$i<=$#letters && $index!=-1;++$i) {
		$index=index $string, $letters[$i], $index+1;
	}
	return $index!=-1;
}

sub rmgir_noprep {
	my $result=1;
	foreach my $text (
		'sigma',
		'stigma',
		'magma',
	) {
		$result &&= findInterleavedString($text, 'sigma');
	}
}

cmpthese -3, { 
				ikegami => \&ikegami,
				ikegami_noprep => \&ikegami_noprep,
				rmgir => \&rmgir,
				rmgir_noprep => \&rmgir_noprep,
			 };