From fed310b12f1ff9a0b03090cb8ae922e940221d68 Mon Sep 17 00:00:00 2001
From: Adam Russell <ac.russell@live.com>
Date: Sun, 10 May 2020 11:28:00 -0400
Subject: solution for challenge 059

---
 challenge-059/adam-russell/blog.txt           |  1 +
 challenge-059/adam-russell/perl/LinkedList.pm | 75 +++++++++++++++++++++++++++
 challenge-059/adam-russell/perl/ch-1.pl       | 22 ++++++++
 challenge-059/adam-russell/perl/ch-2.pl       | 38 ++++++++++++++
 4 files changed, 136 insertions(+)
 create mode 100644 challenge-059/adam-russell/blog.txt
 create mode 100644 challenge-059/adam-russell/perl/LinkedList.pm
 create mode 100644 challenge-059/adam-russell/perl/ch-1.pl
 create mode 100644 challenge-059/adam-russell/perl/ch-2.pl

(limited to 'challenge-059')

diff --git a/challenge-059/adam-russell/blog.txt b/challenge-059/adam-russell/blog.txt
new file mode 100644
index 0000000000..4f5e408d78
--- /dev/null
+++ b/challenge-059/adam-russell/blog.txt
@@ -0,0 +1 @@
+https://adamcrussell.livejournal.com/16202.html
diff --git a/challenge-059/adam-russell/perl/LinkedList.pm b/challenge-059/adam-russell/perl/LinkedList.pm
new file mode 100644
index 0000000000..a340f898e9
--- /dev/null
+++ b/challenge-059/adam-russell/perl/LinkedList.pm
@@ -0,0 +1,75 @@
+use strict;
+use warnings;
+package LinkedList{
+    use boolean;
+    use Tie::RefHash;
+    use Class::Struct;
+    package Node{
+        use Class::Struct;
+
+        struct(
+            data => q/$/,
+            next => q/Node/
+        );
+    }
+
+    struct(
+        head => q/Node/
+    );
+
+    sub stringify{
+        my($self) = @_;
+        my $s = "";
+        my $next = $self->head()->next();
+        while($next && $next->next()){
+            $s .= " -> " if $s; 
+            $s = $s . $next->data();
+            $next = $next->next();
+        }
+        $s = $s . " -> " . $next->data() if $next->data();
+        $s .= "\n"; 
+        return $s;
+    }
+
+    sub insert{
+        my($self, $data, $previous) = @_;
+        if(!$previous){
+            $previous=new Node(data => undef, next => undef);
+            $self->head($previous);
+        }
+        my $next=new Node(data => $data, next => undef);
+        $previous->next($next);
+        return $next;
+    }
+
+    sub partition{
+        my($self, $k) = @_;
+        my $previous = $self->head();
+        my $next = $self->head()->next();
+        tie my %node_value, "Tie::RefHash";
+        while($next){
+            if($next->data() < $k){
+                $node_value{$next} = $next->data();
+                if($next->next()){
+                    $previous->next($next->next());
+                }
+                else{
+                    $previous->next(new Node());
+                    $next = undef;
+                    next;
+                }
+            }
+            $previous = $next;
+            $next = $next->next();
+        }
+        my @sorted_nodes = sort {$node_value{$b} <=> $node_value{$a}} keys %node_value;
+        $previous = $self->head();
+        my $old_first = $previous->next();
+        while(@sorted_nodes){
+           my $node = pop @sorted_nodes;
+           $previous = insert($self,$node->data(), $previous);
+        }
+        $previous->next($old_first);
+    }
+    true;
+}
diff --git a/challenge-059/adam-russell/perl/ch-1.pl b/challenge-059/adam-russell/perl/ch-1.pl
new file mode 100644
index 0000000000..960302b6a3
--- /dev/null
+++ b/challenge-059/adam-russell/perl/ch-1.pl
@@ -0,0 +1,22 @@
+use strict;
+use warnings;
+##
+# Write a script to partition a linked list such that 
+# all nodes less than k come before nodes greater than or equal to k.
+##
+use LinkedList;
+
+MAIN:{
+    my $ll = new LinkedList();
+    my $next = $ll->insert(1, undef);
+    $next = $ll->insert(4, $next);
+    $next = $ll->insert(3, $next);
+    $next = $ll->insert(2, $next);
+    $next = $ll->insert(5, $next);
+    $next = $ll->insert(2, $next);
+    print "Original: "; 
+    print $ll->stringify();
+    $ll->partition(3);
+    print "Partitioned: "; 
+    print $ll->stringify();
+}
diff --git a/challenge-059/adam-russell/perl/ch-2.pl b/challenge-059/adam-russell/perl/ch-2.pl
new file mode 100644
index 0000000000..ea09ad3c25
--- /dev/null
+++ b/challenge-059/adam-russell/perl/ch-2.pl
@@ -0,0 +1,38 @@
+use strict;
+use warnings;
+##
+# Write a function which returns the count of 
+# different bits of the binary representation of 
+# positive numbers a and b. The script should 
+# accept n positive numbers and sum the result 
+# for every pair of numbers given.  
+##
+sub count_different_bits{
+    my($a, $b) = @_;
+    my $bits = 0;
+    while($a || $b){
+        $bits++ if ($a & 1) && !($b & 1);
+        $bits++ if !($a & 1) && ($b & 1);
+        $a = $a >> 1;
+        $b = $b >> 1;
+    }
+    return $bits;
+}
+
+MAIN:{
+    my $sum = 0;
+    my $line; 
+    while($line = <DATA>){
+       chomp($line);
+       my($a, $b) = split(/,/, $line);
+       my $different_bits = count_different_bits($a, $b);
+       print "($a, $b) = $different_bits\n";
+       $sum += $different_bits; 
+    } 
+    print "sum of all bit differences: $sum\n"; 
+}
+
+__DATA__
+2,3
+2,4
+3,4
-- 
cgit