Data commit

Task/Metallic-ratios/Perl/metallic-ratios.pl

@@ -0,0 +1,39 @@
+use strict;
+use warnings;
+use feature qw(say state);
+use Math::AnyNum qw<:overload as_dec>;
+
+sub gen_lucas {
+    my $b = shift;
+    my $i = 0;
+    return sub {
+        state @seq = (state $v1 = 1, state $v2 = 1);
+        ($v2, $v1) = ($v1, $v2 + $b*$v1) and push(@seq, $v1) unless defined $seq[$i+1];
+        return $seq[$i++];
+    }
+}
+
+sub metallic {
+    my $lucas  = shift;
+    my $places = shift || 32;
+    my $n = my $last = 0;
+    my @seq = $lucas->();
+    while (1) {
+        push @seq, $lucas->();
+        my $this = as_dec( $seq[-1]/$seq[-2], $places+1 );
+        last if $this eq $last;
+        $last = $this;
+        $n++;
+    }
+    $last, $n
+}
+
+my @name = <Platinum Golden Silver Bronze Copper Nickel Aluminum Iron Tin Lead>;
+
+for my $b (0..$#name) {
+    my $lucas = gen_lucas($b);
+    printf "\n'Lucas' sequence for $name[$b] ratio, where b = $b:\nFirst 15 elements: " . join ', ', map { $lucas->() } 1..15;
+    printf "Approximated value %s reached after %d iterations\n", metallic(gen_lucas($b));
+}
+
+printf "\nGolden ratio to 256 decimal places %s reached after %d iterations", metallic(gen_lucas(1),256);