6 files changed, 151 insertions, 0 deletions
diff --git a/challenge-102/adam-russell/blog.txt b/challenge-102/adam-russell/blog.txt
new file mode 100644
index 0000000000..3b012b2385
--- /dev/null
+++ b/challenge-102/adam-russell/blog.txt
@@ -0,0 +1 @@
+http://www.rabbitfarm.com/cgi-bin/blosxom/perl/2021/03/07
+\ No newline at end of file
diff --git a/challenge-102/adam-russell/blog1.txt b/challenge-102/adam-russell/blog1.txt
new file mode 100644
index 0000000000..4503e3ca0c
--- /dev/null
+++ b/challenge-102/adam-russell/blog1.txt
@@ -0,0 +1 @@
+http://www.rabbitfarm.com/cgi-bin/blosxom/prolog/2021/03/07
+\ No newline at end of file
diff --git a/challenge-102/adam-russell/perl/ch-1.pl b/challenge-102/adam-russell/perl/ch-1.pl
new file mode 100644
index 0000000000..a207875027
--- /dev/null
+++ b/challenge-102/adam-russell/perl/ch-1.pl
@@ -0,0 +1,64 @@
+use strict;
+use warnings;
+##
+# You are given a positive integer $N.
+# Write a script to generate all Rare Numbers of size $N, if any exist.
+##
+use Thread;
+use constant THREAD_COUNT => 4;
+
+sub rare_number_check{
+    my($lower, $upper) = @_;
+    my @rares; 
+    {
+        my $r = $lower;
+        my $r1 = reverse($r);  
+        if($r > $r1){
+            my $rs = sqrt($r + $r1);  
+            my $r1s = sqrt($r - $r1);  
+            if($rs !~ m/\./ && $r1s !~ m/\./){
+                push @rares, $lower; 
+            } 
+        } 
+        $lower++; 
+        redo unless $lower > $upper;
+    }  
+    return \@rares;
+}
+
+sub rare_number{
+    my($n) = @_;
+    my @rares; 
+    my $lower = "1" . 0 x ($n - 1);
+    my $upper = "1" . 9 x ($n - 1);
+    my $increment = $lower;
+    {
+        my @threads;
+        for(1 .. THREAD_COUNT){
+            my $t = Thread->new(\&rare_number_check, $lower, $upper); 
+            push @threads, $t;
+            $lower = $upper + 1;
+            $upper = $lower + $increment - 1;  
+            last if(length($upper) == ($n + 1)); 
+        }
+        foreach my $t (@threads){
+            my $rares = $t->join();
+            push @rares, @{$rares}; 
+        }  
+        redo unless(length($upper) == ($n + 1)); 
+    }
+    return \@rares;  
+}
+
+MAIN:{
+    my($N);
+    $N=2;
+    my $rares = rare_number($N); 
+    print "$N digits: " . join(" ", @{$rares}) . "\n";
+    $N=6;
+    $rares = rare_number($N); 
+    print "$N digits: " . join(" ", @{$rares}) . "\n";
+    $N=9;
+    $rares = rare_number($N); 
+    print "$N digits: " . join(" ", @{$rares}) . "\n";
+} 
diff --git a/challenge-102/adam-russell/perl/ch-2.pl b/challenge-102/adam-russell/perl/ch-2.pl
new file mode 100644
index 0000000000..62722ff918
--- /dev/null
+++ b/challenge-102/adam-russell/perl/ch-2.pl
@@ -0,0 +1,22 @@
+use strict;
+use warnings;
+##
+# You are given a positive integer $N.
+# Write a script to produce a hash counting string
+# of that length.
+##
+sub hash_counting_string{
+    my($n) = @_;
+    return "" if $n == 0; 
+    return "#" if $n == 1; 
+    my $h = "$n#";  
+    return hash_counting_string($n - length($h)) . $h;  
+}
+
+MAIN:{
+    print hash_counting_string(1). "\n";
+    print hash_counting_string(2). "\n";
+    print hash_counting_string(3). "\n";
+    print hash_counting_string(10). "\n";
+    print hash_counting_string(14). "\n";
+}
diff --git a/challenge-102/adam-russell/prolog/ch-1.p b/challenge-102/adam-russell/prolog/ch-1.p
new file mode 100644
index 0000000000..929f1520c4
--- /dev/null
+++ b/challenge-102/adam-russell/prolog/ch-1.p
@@ -0,0 +1,34 @@
+:-initialization(main).
+
+perfect_square(N):-
+    A is floor(sqrt(N)), 
+    N is A * A.
+
+rare(N, N, Rares, Rares). 
+rare(Lower, Upper, RareAccum, Rares):-
+    number_codes(Lower, C),
+    reverse(C, CR), 
+    number_codes(R1, CR),
+    X0 is Lower + R1,
+    X1 is Lower - R1,
+    perfect_square(X0),
+    perfect_square(X1),
+    Next is Lower + 1,
+    rare(Next, Upper, [Lower|RareAccum], Rares).
+rare(Lower, Upper, RareAccum, Rares):-
+    Next is Lower + 1,
+    rare(Next, Upper, RareAccum, Rares).
+
+rare_numbers(N, Rares):-
+    Lower is 10 ^ (N - 1),   
+    Upper is (10 ^ N) - 1,
+    rare(Lower, Upper, [], Rares). 
+
+main:-
+    rare_numbers(2, Rares2),
+    write(Rares2), nl, 
+    rare_numbers(6, Rares6),
+    write(Rares6), nl, 
+    rare_numbers(9, Rares9),
+    write(Rares9), nl,
+    halt.
diff --git a/challenge-102/adam-russell/prolog/ch-2.p b/challenge-102/adam-russell/prolog/ch-2.p
new file mode 100644
index 0000000000..b62179b8e0
--- /dev/null
+++ b/challenge-102/adam-russell/prolog/ch-2.p
@@ -0,0 +1,29 @@
+:-initialization(main).
+
+hcs(0, String, String).
+hcs(1, StringAccum, String):-
+    hcs(0, [35|StringAccum], String). 
+hcs(N, StringAccum, String):-
+    number_codes(N, C),
+    append(C, "#", Accum), 
+    length(Accum, L),
+    N0 is N - L, 
+    append(Accum, StringAccum, StringAccum0), 
+    hcs(N0, StringAccum0, String). 
+
+hash_counting_string(N, String):-
+    hcs(N, [], S),
+    atom_codes(String, S).
+
+main:-
+    hash_counting_string(1, String1), 
+    write(String1), nl,
+    hash_counting_string(2, String2), 
+    write(String2), nl, 
+    hash_counting_string(3, String3), 
+    write(String3), nl, 
+    hash_counting_string(10, String10), 
+    write(String10), nl, 
+    hash_counting_string(14, String14), 
+    write(String14), nl,
+    halt.