sgreen solutions to challenge 169

5 files changed, 245 insertions, 2 deletions

diff --git a/challenge-169/sgreen/README.md b/challenge-169/sgreen/README.md
index 9b6e026bc2..9956720a38 100644
--- a/challenge-169/sgreen/README.md
+++ b/challenge-169/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 158
+# The Weekly Challenge 169
 
-Blog: [Weekly Challenge 160](https://dev.to/simongreennet/weekly-challenge-160-3206)
\ No newline at end of file
+Blog: [It's all about the numbers](https://dev.to/simongreennet/its-all-about-the-numbers-4fh5)
\ No newline at end of file
diff --git a/challenge-169/sgreen/perl/ch-1.pl b/challenge-169/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..04ded95aa7
--- /dev/null
+++ b/challenge-169/sgreen/perl/ch-1.pl
@@ -0,0 +1,63 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+sub is_prime ($number) {
+    # Return true or false if the number is a prime
+    if ( $number < 2 ) {
+        return;
+    }
+
+    foreach my $i ( 2 .. int( sqrt($number) ) ) {
+        if ( $number % $i == 0 ) {
+            return;
+        }
+    }
+
+    # It's a prime
+    return 1;
+}
+
+sub numerical { $a <=> $b }
+
+sub get_bril_nums ($l) {
+    # Get all primes of length l
+    my @primes = ();
+    foreach my $i ( 10**( $l - 1 ) .. 10**$l ) {
+        if ( is_prime($i) ) {
+            push @primes, $i;
+        }
+    }
+
+    # Calculate all brilliant numbers
+    my @bril_nums = ();
+    while ( my ( $i, $v1 ) = each @primes ) {
+        foreach my $v2 ( @primes[ $i .. $#primes ] ) {
+            say "$i $v1 $v2";
+            push @bril_nums, $v1 * $v2;
+        }
+    }
+
+    # Return the sorted list
+    return sort numerical @bril_nums;
+}
+
+sub main() {
+    my $l         = 1;
+    my @bril_nums = ();
+
+    # Keep increasing the length of primes until we have at least twenty
+    #  solutions
+    while ( scalar(@bril_nums) < 20 ) {
+        push @bril_nums, get_bril_nums($l);
+        $l++;
+    }
+
+    # Print the first 20 numbers
+    say join ', ', @bril_nums[ 0 .. 19 ];
+}
+
+main();
diff --git a/challenge-169/sgreen/perl/ch-2.pl b/challenge-169/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..c557782966
--- /dev/null
+++ b/challenge-169/sgreen/perl/ch-2.pl
@@ -0,0 +1,70 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+use List::Util qw(all any min);
+
+sub is_achilles_number ($num) {
+    # Get the prime factors of the number
+    my %factors = ();
+
+    my $i = 2;
+    while ( $num > 1 ) {
+        if ( $num % $i == 0 ) {
+            $num /= $i;
+            if ( exists( $factors{$i} ) ) {
+                $factors{$i}++;
+            }
+            else {
+                $factors{$i} = 1;
+            }
+        }
+        else {
+            $i++;
+        }
+    }
+
+    # If there is only one prime factor, it is not an achilles number
+    if ( scalar( keys %factors ) == 1 ) {
+        return;
+    }
+
+    # Get a list of unique powers
+    my @powers = values(%factors);
+
+    # It's also not an achilles number if any of the powers were 1, or the
+    #  powers are all the same (a perfect sqaure)
+    if ( $#powers == 0 or any { $_ == 1 } @powers ) {
+        return;
+    }
+
+    # Finally, the greatest common divisor of these numbers has to be one
+    foreach my $i ( 2 .. min(@powers) ) {
+        if ( all { $_ % $i == 0 } @powers ) {
+            return;
+        }
+    }
+
+    return 1;
+}
+
+sub main() {
+    my @solutions = ();
+    my $num       = 2;
+
+    # Get the first 20 achilles numbers
+    while ( $#solutions < 19 ) {
+        if ( is_achilles_number($num) ) {
+            push @solutions, $num;
+        }
+        $num++;
+    }
+
+    # Print the list
+    say join ', ', @solutions;
+}
+
+main();
\ No newline at end of file
diff --git a/challenge-169/sgreen/python/ch-1.py b/challenge-169/sgreen/python/ch-1.py
new file mode 100755
index 0000000000..dee277497c
--- /dev/null
+++ b/challenge-169/sgreen/python/ch-1.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+
+import math
+
+
+def is_prime(number):
+    '''Return true or false if the number is a prime'''
+    if number < 2:
+        return False
+
+    for i in range(2, int(math.sqrt(number)) + 1):
+        if number % i == 0:
+            return False
+
+    # It's a prime
+    return True
+
+
+def get_bril_nums(l):
+    '''Get all primes of length l'''
+
+    primes = []
+    for i in range(10**(l-1), 10**l):
+        if is_prime(i):
+            primes.append(i)
+
+    # Calculate all brilliant numbers
+    bril_nums = []
+    for i, v1 in enumerate(primes):
+        for v2 in primes[i:]:
+            bril_nums.append(v1*v2)
+
+    # Return the sorted list
+    bril_nums.sort()
+    return bril_nums
+
+
+def main():
+    '''Find the first twenty brilliant numbers'''
+    l = 1
+    bril_nums = []
+
+    # Keep increasing the length of primes until we have at least twenty
+    #  solutions
+    while len(bril_nums) < 20:
+        bril_nums.extend(get_bril_nums(l))
+        l += 1
+
+    # Print the first 20 numbers
+    print(*bril_nums[0:20], sep=', ')
+
+
+if __name__ == '__main__':
+    main()
diff --git a/challenge-169/sgreen/python/ch-2.py b/challenge-169/sgreen/python/ch-2.py
new file mode 100755
index 0000000000..3cd0323f3a
--- /dev/null
+++ b/challenge-169/sgreen/python/ch-2.py
@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+
+def is_achilles_number(num):
+    '''Determine if this number is an achilles numbers'''
+
+    # Get the prime factors of the number
+    factors = {}
+
+    i = 2
+    while num > 1:
+        if num % i == 0:
+            num /= i
+            if i in factors:
+                factors[i] += 1
+            else:
+                factors[i] = 1
+        else:
+            i += 1
+
+    # If there is only one prime factor, it is not an achilles number
+    if len(factors) == 1:
+        return False
+
+    # Get a list of unique powers
+    powers = set(factors.values())
+
+    # It's also not an achilles number if any of the powers were 1, or the
+    #  powers are all the same (a perfect sqaure)
+    if 1 in powers or len(powers) == 1:
+        return False
+
+    # Finally, the greatest common divisor of these numbers has to be one
+    for i in range(2, min(powers)+1):
+        if all(x % i == 0 for x in powers):
+            return False
+
+    return True
+
+
+def main():
+    '''Find the first 20 achilles numbers'''
+    solutions = []
+    num = 2
+
+    # Get the first 20 achilles numbers
+    while len(solutions) < 20:
+        if is_achilles_number(num):
+            solutions.append(num)
+        num += 1
+
+    # Print the list
+    print(*solutions, sep=', ')
+
+
+if __name__ == '__main__':
+    main()