solutions for challenge 020

3 files changed, 73 insertions, 0 deletions

diff --git a/challenge-020/adam-russell/blog.txt b/challenge-020/adam-russell/blog.txt
new file mode 100644
index 0000000000..c6d4916e2f
--- /dev/null
+++ b/challenge-020/adam-russell/blog.txt
@@ -0,0 +1 @@
+https://adamcrussell.livejournal.com/6526.html
diff --git a/challenge-020/adam-russell/perl5/ch-1.pl b/challenge-020/adam-russell/perl5/ch-1.pl
new file mode 100644
index 0000000000..7ca9fbd9e3
--- /dev/null
+++ b/challenge-020/adam-russell/perl5/ch-1.pl
@@ -0,0 +1,18 @@
+use strict;
+use warnings;
+##
+# Write a script to accept a string from command line and split it on change of character.
+##
+my $string = $ARGV[0];
+my @letters = split(//, $string);
+my $letter;
+my $letter_previous = shift @letters;
+do{ 
+    $letter = shift @letters;
+    print $letter_previous if($letter eq $letter_previous); 
+    print "$letter_previous\n" if($letter ne $letter_previous); 
+    $letter_previous = $letter; 
+}while(@letters);
+print $letter_previous if($letter eq $letter_previous); 
+print "$letter_previous\n" if($letter ne $letter_previous);
+print "\n";  
diff --git a/challenge-020/adam-russell/perl5/ch-2.pl b/challenge-020/adam-russell/perl5/ch-2.pl
new file mode 100644
index 0000000000..e86084b6c7
--- /dev/null
+++ b/challenge-020/adam-russell/perl5/ch-2.pl
@@ -0,0 +1,54 @@
+use strict;
+use warnings;
+##
+# Write a script to print the smallest pair of Amicable Numbers.
+##
+use boolean; 
+use Thread;
+use constant RANGE_SIZE => 50; 
+use constant THREAD_COUNT => 4;  
+
+sub factor_sum{ 
+    my(@numbers) = @_;
+    my %number_sof; 
+    foreach my $n (@numbers){  
+        my @factors = (1);
+            foreach my $j (2..sqrt($n)){
+            push @factors, $j if $n % $j == 0;
+            push @factors, ($n / $j) if $n % $j == 0 && $j ** 2 != $n;
+        }    
+        $number_sof{$n}=unpack("%32C*", pack("C*", @factors));  
+    } 
+    return \%number_sof;   
+}
+
+MAIN:{
+    my %number_sof; 
+    my @threads;
+    my $range_start = 1;
+    my $range_end = RANGE_SIZE; 
+    my $found = false; 
+    do{
+        for(0 .. (THREAD_COUNT - 1)){
+            my $t = Thread->new(\&factor_sum, ($range_start .. $range_end)); 
+            push @threads, $t;  
+            $range_start = $range_end + 1;
+            $range_end = $range_start + RANGE_SIZE;  
+        }  
+        foreach my $t (@threads){
+            my $sof = $t->join();
+            @number_sof{keys %{$sof}} = values %{$sof};  
+            foreach my $k (values %{$sof}){
+                if($number_sof{$k}){
+                    if($number_sof{$number_sof{$k}} && 
+                       $number_sof{$number_sof{$k}} == $k && 
+                       $number_sof{$k} != $k && !$found){
+                           print "First amicable pair of numbers: $k " . $number_sof{$k} . " \n"; 
+                           $found = true;   
+                    }    
+                }  
+            }     
+        }  
+        @threads = (); 
+    }while(!$found);     
+}