Challenge 1 solution, nested loops

1 files changed, 62 insertions, 0 deletions

diff --git a/challenge-003/bob-lied/perl/ch-1.pl b/challenge-003/bob-lied/perl/ch-1.pl
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+#!/usr/bin/env perl
+# vim:set ts=4 sw=4 sts=4 et ai wm=0 nu:
+#=============================================================================
+# ch-1.pl
+#=============================================================================
+# Copyright (c) 2021, Bob Lied
+#=============================================================================
+# Perl Weekly challenge Week 3, Challenge #1
+# Create a script to generate 5-smooth numbers, whose prime divisors are less
+# or equal to 5. They are also called Hamming/Regular/Ugly numbers. For more
+# information, please check this wikipedia.
+# "... numbers are called 5-smooth, because they can be characterized as
+# having only 2, 3, or 5 as prime factors. ..."
+#=============================================================================
+
+use strict;
+use warnings;
+use v5.32;
+
+use experimental qw/ signatures /;
+no warnings "experimental::signatures";
+
+use Getopt::Long;
+my $Verbose = 0;
+my $DoTest  = 0;
+
+GetOptions("test" => \$DoTest, "verbose" => \$Verbose);
+my $Max = shift;
+$Max //= 100;
+
+sub fiveSmooth($max)
+{
+    my @smoothNumbers;
+    for ( my $mult2 = 1; $mult2 <= $max ; $mult2 *= 2 )
+    {
+        for ( my $mult3 = $mult2 ; $mult3 <= $max ; $mult3 *= 3 )
+        {
+            for ( my $mult5 = $mult3 ; $mult5 <= $max ; $mult5 *= 5 )
+            {
+                push @smoothNumbers, $mult5 unless $mult5 == 1;    # Not in order
+            }
+        }
+    }
+    return \@smoothNumbers;
+}
+exit(!runTest()) if $DoTest;
+my $smoothList = fiveSmooth($Max);
+say $_ foreach sort { $a <=> $b} @$smoothList;
+
+sub runTest
+{
+    use Test::More;
+
+    is_deeply( fiveSmooth( 2), [ 2 ], "max = 2");
+    is_deeply( fiveSmooth( 3), [ 2, 3 ], "max = 3");
+    is_deeply( fiveSmooth( 5), [ 2, 3, 4, 5 ], "max = 5");
+    is_deeply( fiveSmooth(10), [ 2, 3, 4, 5, 6, 8, 9, 10  ], "max = 10");
+    is_deeply( fiveSmooth(20), [ 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20 ], "max = 20");
+
+    done_testing;
+}
+