Merge pull request #534 from Doomtrain14/master

code update

2 files changed, 46 insertions, 24 deletions

diff --git a/challenge-022/yet-ebreo/perl5/ch-1.pl b/challenge-022/yet-ebreo/perl5/ch-1.pl
index b0a1bae4a4..fbc68cb5fd 100644
--- a/challenge-022/yet-ebreo/perl5/ch-1.pl
+++ b/challenge-022/yet-ebreo/perl5/ch-1.pl
@@ -1,7 +1,15 @@
-# Write a script to print first 10 Sexy Prime Pairs. 
-# Sexy primes are prime numbers that differ from each other by 6. 
-# For example, the numbers 5 and 11 are both sexy primes, because 11 - 5 = 6. 
+# Write a script to print first 10 Sexy Prime Pairs.
+# Sexy primes are prime numbers that differ from each other by 6.
+# For example, the numbers 5 and 11 are both sexy primes, because 11 - 5 = 6.
 # The term “sexy prime” is a pun stemming from the Latin word for six: sex.
 
-@_=grep{@_[ map $x*$_,//..@_/($x=$_) ] =0 if $_[$_] > 1}@_=0..54;
+#This part determines the primes from 0 to 54 using sieve of eratosthenes
+#Multiple of each current value (from 0..54) are set to 0 leaving only those
+#which are not (Primes)
+@_=grep{@_[ map $x*$_,$_..@_/($x=$_) ] =0 if $_[$_] > 1}@_=0..54;
+
+#The ocde below go through the primes generated above and print combinations
+#which have difference of +6
 map { ($_[$_]-$_[$'] == 6) && print "$_[$'] $_[$_]\n" for  $_+//..$#_ } 0..$#_;
+
+#My love for obfuscated code strikes again, sorry ;)
diff --git a/challenge-022/yet-ebreo/perl5/ch-2.pl b/challenge-022/yet-ebreo/perl5/ch-2.pl
index 3d96301c0b..9ad27f72b5 100644
--- a/challenge-022/yet-ebreo/perl5/ch-2.pl
+++ b/challenge-022/yet-ebreo/perl5/ch-2.pl
@@ -10,21 +10,24 @@ sub encode {
     my $string      = pop;
     my $len         = length $string;
 
+    #Initialize the dictionary to hash
     my $dict_size   = INIT_DICT_SIZE;
-    my %dictionary  = map { chr($_) => $_ }0..$dict_size;
-    
-    my $bin_buff    = "";
+    my %dictionary  = map { chr $_ => $_ } 0..$dict_size;
+
+    #Initialize variables
     my @buff_out    = ();
     my $pos         = 0;
     my $output      = "";
     my $l           = "";
     my $v           = "";
 
+    #Go through the characters and build-up the $dictionary
     while ($pos<$len) {
         my $incr = 1;
         for my $x ($pos+1..$len) {
-            $l    = substr $string, $pos, $x-$pos;
-            
+            $l = substr $string, $pos, $x-$pos;
+
+            #Check if current L value is in the $dictionary
             if (exists $dictionary{$l}) {
                 $v = $dictionary{$l};
 
@@ -34,7 +37,7 @@ sub encode {
                 }
             } else {
                 $incr = $x - $pos-1;
-
+                #Store last value to @buff_out and update the $dictionary
                 push @buff_out, $v;
                 $dictionary{$l} = ++$dict_size;
                 last;
@@ -47,29 +50,45 @@ sub encode {
 
 sub decode {
     my @buff_in     = @{+pop};
+
+    #Initialize dictionary using numbers as keys
+    #Using array would work too
     my %dictionary  = map { $_ => chr }0..INIT_DICT_SIZE;
-    my $old         = $buff_in[0];
-    my $n           = "";
 
-    my $s           = $dictionary{$old};
+    #Initialize the first value from @buff_in to $o
+    my $o           = $buff_in[0];
+    my $n           = "";
+    my $s           = $dictionary{$o};
     my $c           = substr $s, 0, 1;
     my $ret         = $s;
+
+
     my $count       = INIT_DICT_SIZE;
 
+    #Go through the codes in @buff_in
     for (my $i =0; $i < $#buff_in;$i++) {
+
+        #Store the $n-ext value
         $n = $buff_in[$i+1];
 
-        if ( !exists $dictionary{$n} ) {
-            $s = $dictionary{$old};
-            $s.= $c;
-        } else {
+        #Check if $n-ext value is in the dictionary
+        if ( exists $dictionary{$n} ) {
             $s = $dictionary{$n};
+        } else {
+            $s = $dictionary{$o};
+            $s.= $c;
         }
+
+        #Update return value
         $ret .= $s;
         $c = substr $s, 0, 1;
-        $dictionary{++$count} = $dictionary{$old}.$c;
 
-        $old = $n;
+        #Update dictionary
+        $dictionary{++$count} = $dictionary{$o}.$c;
+
+        #Update store $n to $o as
+        #new value becomes old and be replaced on next iteration
+        $o = $n;
     }
     return $ret;
 }
@@ -87,8 +106,3 @@ print ("Uncompressed String has length ". (length $uncompressed)."\n");
 print "$uncompressed\n\n";
 
 print "Uncompressed string matches original\n\n" if $uncompressed eq $string;
-
-
-
-
-