Basic working version for ch-2.p5

1 files changed, 58 insertions, 0 deletions

diff --git a/challenge-022/ruben-westerberg/perl5/ch-2.pl b/challenge-022/ruben-westerberg/perl5/ch-2.pl
new file mode 100755
index 0000000000..aa504468d6
--- /dev/null
+++ b/challenge-022/ruben-westerberg/perl5/ch-2.pl
@@ -0,0 +1,58 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use v5.26;
+
+# implement LZW 
+my @symbols= 'A'..'Z';
+my @indexes;
+for (split "","TOBEORNOTTOBEORTOBEORNOT") {
+	my $res=encode(\@symbols, $_);
+	if ($res) {
+		push @indexes, $res
+	}
+}
+my $res=encode(\@symbols, $_);
+if ($res) {
+	push @indexes, $res
+}
+print join ",",@indexes;
+
+for (@indexes) {
+	print decode(\@symbols,$_),"\n";
+}
+sub encode {
+	state $symbol="";
+	my $dict=shift;
+	state $count= @$dict;
+	my $next=shift;
+	$symbol.=$next if defined $next;
+	print "Symbol: ",$symbol,"\n";
+	state $prev="";
+	print "Prev: ",$prev,"\n";
+	my $s=(grep {$symbol eq $_} @$dict)[0];
+	print "$s\n";
+	print "$symbol\n";
+	my $res;
+	if (defined $s and  $next) {
+		#found existing keep adding
+		$res=undef;
+	}
+	else {
+		#add new symbol
+		print "New symbol $symbol\n";
+		#$$dict{$symbol}=$count++;
+		push @$dict, $symbol;
+		$res=(grep {$prev eq $$dict[$_]} 0..@$dict-1)[0];
+		$symbol=substr $symbol, -1;
+	}
+	$prev=$symbol;
+	$res;
+}
+
+
+sub decode {
+	my $dict=shift;
+	my $code=shift;	
+	@$dict[$code];
+}