gistfile1.pl

# Decrypt
my $text = "Uid nx, aex jcdjipx iu wzux zp, ta wxtpa jtdaws, ai etkx vis.\n" .
  	   "Dcos zyexdzaxr aex Jxdw jezwipijes iu etkzyg nidx aety iyx hts\n" .
		   "ai ri aex ptnx aezyg. Z zyexdzaxr aeta jezwipijes udin Wtdds Htww,\n" .
		   "hei zp ns exdi tqactwws. Z htya ai ntfx Dcos cpxdp udxx. Z htya ai\n" .
		   "gzkx aexn aex udxxrin ai qeiipx. Jxijwx tdx rzuuxdxya. Jxijwx qeiipx\n" .
		   "rzuuxdxya qdzaxdzt. Oca zu aexdx zp t oxaaxd hts tniyg ntys\n" .
		   "twaxdytazkxp, Z htya ai xyqicdtgx aeta hts os ntfzyg za qinuidatowx.\n" .
		   "Pi aeta'p heta Z'kx adzxr ai ri.\n" .
		   "Z htya ai piwkx jdiowxnp Z nxxa zy aex rtzws wzux os cpzyg qinjcaxdp,\n" .
		   "pi Z yxxr ai hdzax jdigdtnp. Os cpzyg Dcos, Z htya ai qiyqxyadtax aex\n" .
		   "aezygp Z ri, yia aex ntgzqtw dcwxp iu aex wtygctgx, wzfx patdazyg hzae\n" .
		   "jcowzq kizr  pinxaezyg pinxaezyg pinxaezyg ai pts, \"jdzya exwwi hidwr.\"\n" .
		   "Z vcpa htya ai pts, \"jdzya aezp!\" Z riy'a htya tww aex pcddicyrzyg\n" .
		   "ntgzq fxshidrp. Z vcpa htya ai qiyqxyadtax iy aex atpf. Aeta'p aex otpzq\n" .
		   "zrxt. Pi Z etkx adzxr ai ntfx Dcos qirx qiyqzpx tyr pcqqzyqa.\n" .
		   "Scfzezdi Ntapcniai. (hhh.tdaznt.qin/zyak/dcos)";

my $freqLang = "TEOIARNSHLMYUCWDGPFBVKJ";

my $len = length( $text );
my %frequency;

for( my $k = 0; $k < $len; $k++ )
{
	my $c = uc( substr( $text, $k, 1 ) );
	if( $c =~ /[A-Z]/ )
	{
		if( exists( $frequency{ $c } ) )	{ $frequency{ $c } = $frequency{ $c } + 1; }
		else								{ $frequency{ $c } = 1; }
	}
}

my %dic;
my $freqText;
my $index = 0;

# Sort in descending order
foreach( sort( {$frequency{$b}<=>$frequency{$a}} keys( %frequency ) ) )
{
	#print( $_, " - ", $frequency{ $_ }, "\n" );
	$freqText .= $_;
	$dic{ uc( $_ ) } = substr( $freqLang, $index++, 1);
}
println( $freqText );
println( $freqLang );

my $decrypted;
$len = length( $text );

for( my $k = 0; $k < $len; $k++ )
{
	my $uper = 0;
	my $c = substr( $text, $k, 1 );
	if( $c =~ /[A-Z]/ )	{ $uper = 1; }
	else				{ $c = uc( $c ); }
	if( exists( $dic{ $c } ) )
	{
		if( $uper )	{ $decrypted .= $dic{ $c }; }
		else		{ $decrypted .= lc( $dic{ $c } ); }
	}
	else { $decrypted .= $c; }
}

println( $decrypted );