Merge pull request #552 from adamcrussell/challenge-022

Challenge 022

3 files changed, 113 insertions, 0 deletions

diff --git a/challenge-022/adam-russell/blog.txt b/challenge-022/adam-russell/blog.txt
new file mode 100644
index 0000000000..6ac9c77e8b
--- /dev/null
+++ b/challenge-022/adam-russell/blog.txt
@@ -0,0 +1 @@
+https://adamcrussell.livejournal.com/7521.html
diff --git a/challenge-022/adam-russell/perl5/ch-1.pl b/challenge-022/adam-russell/perl5/ch-1.pl
new file mode 100644
index 0000000000..ecb9a0905d
--- /dev/null
+++ b/challenge-022/adam-russell/perl5/ch-1.pl
@@ -0,0 +1,41 @@
+use strict;
+use warnings;
+##
+# Write a script to print the first 10 sexy prime numbers.
+##
+use boolean; 
+use LWP::UserAgent;
+use constant PRIME_URL => "http://primes.utm.edu/lists/small/100000.txt";
+
+sub get_primes{
+    my @primes;  
+    my $ua = new LWP::UserAgent(
+        ssl_opts => {verify_hostname => 0}
+    );
+    my $response = $ua->get(PRIME_URL);
+    my @lines = split(/\n/,$response->decoded_content);  
+    foreach my $line (@lines){
+        my @p = split(/\s+/, $line);
+        unless(@p < 10){
+            push @primes, @p[1..(@p - 1)]; 
+        }  
+    }
+    return @primes; 
+}
+
+MAIN:{
+    my @sexy;   
+    my @primes = get_primes();  
+    for my $i (0 .. (@primes - 1)){
+        for my $j (($i + 1) .. (@primes - 1)){
+            last if($primes[$j] - $primes[$i] > 6); 
+            push @sexy, [$primes[$i], $primes[$j]] if($primes[$j] - $primes[$i] == 6); 
+            last if(@sexy == 10); 
+        }  
+        last if(@sexy == 10); 
+    }   
+    for my $pair (@sexy){
+        print "[" . join(", ", @{$pair}) . "]";  
+    }
+    print "\n";
+}  
diff --git a/challenge-022/adam-russell/perl5/ch-2.pl b/challenge-022/adam-russell/perl5/ch-2.pl
new file mode 100644
index 0000000000..066f0834d5
--- /dev/null
+++ b/challenge-022/adam-russell/perl5/ch-2.pl
@@ -0,0 +1,71 @@
+use strict;
+use warnings;
+##
+# Write a script to implement Lempel–Ziv–Welch (LZW) compression algorithm.
+##
+use constant TABLE_SIZE => 256;
+
+sub initialize_table{
+    my $code = 0; 
+    my %compression_table;
+    do{
+        $compression_table{chr($code)} = $code++;
+    }while($code < TABLE_SIZE); 
+    return %compression_table; 
+}  
+
+sub encode{
+    my($string) = @_;
+    my %compression_table = initialize_table();
+    my $code = keys %compression_table; 
+    my @encoded;
+    my @characters = split(//, $string); 
+    my $p = shift @characters; 
+    while(@characters){
+        my $c = shift @characters; 
+        if($compression_table{"$p$c"}){
+            $p = "$p$c"; 
+        } 
+        else{
+            push @encoded, $compression_table{$p};  
+            $compression_table{"$p$c"} = $code++;
+            $p = $c; 
+        }  
+    }
+    push @encoded, $compression_table{$p};  
+    return @encoded; 
+}
+
+sub decode{
+    my(@codes) = @_;
+    my %decoding_table = reverse(initialize_table());
+    my $code = keys %decoding_table; 
+    my $string = ""; 
+    my $p = shift @codes;
+    my $c; 
+    $string = $decoding_table{$p};
+    while(@codes){
+        $c = shift @codes;
+        my $entry = $decoding_table{$c}; 
+        $string .= $entry;
+        my $first_character = substr($entry, 0, 1);     
+        my $string_previous = $decoding_table{$p};
+        $decoding_table{$code++} = "$string_previous$first_character"; 
+        $p = $c; 
+    }  
+    return $string; 
+}  
+
+MAIN:{
+    my $text = <DATA>;
+    chomp($text); 
+    initialize_table();  
+    print join(" ", encode($text));  
+    print "\n"; 
+    print decode(encode($text));  
+    print "\n"; 
+}  
+
+
+__DATA__
+Abra abracadabra