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-rwxr-xr-xchallenge-147/steven-wilson/javascript/ch-02.js38
-rw-r--r--challenge-147/steven-wilson/perl/ch-02.pl41
2 files changed, 79 insertions, 0 deletions
diff --git a/challenge-147/steven-wilson/javascript/ch-02.js b/challenge-147/steven-wilson/javascript/ch-02.js
new file mode 100755
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+++ b/challenge-147/steven-wilson/javascript/ch-02.js
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+#!/usr/bin/env node
+// Week 147 Task 2
+// Pentagon Numbers
+// Write a sript to find the first pair of Pentagon Numbers
+// whose sum and difference are also a Pentagon Number.
+// Answer: First pair is 1560090 and 7042750
+
+var pentagonal_numbers = [1]
+var pair_found = false
+var number = 2
+
+while (!pair_found) {
+ let next_pn = pentagonal_number(number)
+ for (let i = 0; i < pentagonal_numbers.length; i++) {
+ if ((is_pentagonal_number(next_pn - pentagonal_numbers[i])) &&
+ (is_pentagonal_number(next_pn + pentagonal_numbers[i]))) {
+ console.log('First pair are ' + pentagonal_numbers[i] + ' and ' + next_pn)
+ pair_found = true
+ break
+ }
+ }
+ pentagonal_numbers.push(next_pn)
+ number++
+}
+
+function pentagonal_number (number) {
+ return ( ( 3 * ( number * number ) ) - number ) / 2
+}
+
+function is_pentagonal_number (number) {
+ let remainder = ( Math.sqrt( 24 * number + 1 ) + 1 ) % 6;
+ if ( remainder > 0 ) {
+ return false
+ }
+ else {
+ return true
+ }
+}
diff --git a/challenge-147/steven-wilson/perl/ch-02.pl b/challenge-147/steven-wilson/perl/ch-02.pl
new file mode 100644
index 0000000000..d1bf716a76
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+++ b/challenge-147/steven-wilson/perl/ch-02.pl
@@ -0,0 +1,41 @@
+#!/usr/bin/env perl
+# Week 147 Task 2
+# Pentagon Numbers
+# Write a sript to find the first pair of Pentagon Numbers
+# whose sum and difference are also a Pentagon Number.
+# Answer: First pair is 1560090 and 7042750
+
+use strict;
+use warnings;
+use feature qw/ say /;
+use POSIX qw/ fmod /;
+
+my @pentagonal_numbers = qw/ 1 /;
+my $first_pair_found = 0;
+my $number = 2;
+
+while ( not $first_pair_found ) {
+ my $next_pn = pentagonal_number($number);
+ for (@pentagonal_numbers) {
+ if ( is_pentagonal_number( $next_pn - $_ )
+ and is_pentagonal_number( $next_pn + $_ ) )
+ {
+ say "First pair is $_ and $next_pn";
+ $first_pair_found = 1;
+ last;
+ }
+ }
+ push @pentagonal_numbers, $next_pn;
+ $number++;
+}
+
+sub pentagonal_number {
+ my $n = shift;
+ return ( ( 3 * ( $n * $n ) ) - $n ) / 2;
+}
+
+sub is_pentagonal_number {
+ my $x = shift;
+ my $remainder = fmod( sqrt( 24 * $x + 1 ) + 1, 6 );
+ $remainder > 0 ? return 0 : return 1;
+}