Merge pull request #3595 from boblied/master

PWC 99 solutions

3 files changed, 164 insertions, 2 deletions

diff --git a/challenge-100/bob-lied/README b/challenge-100/bob-lied/README
index be9398e9a3..bcd73da742 100644
--- a/challenge-100/bob-lied/README
+++ b/challenge-100/bob-lied/README
@@ -1,3 +1,3 @@
-Solutions to weekly challenge 83 by Bob Lied.
+Solutions to weekly challenge 100 by Bob Lied.
 
-https://perlweeklychallenge.org/blog/perl-weekly-challenge-083/
+https://perlweeklychallenge.org/blog/perl-weekly-challenge-100/
diff --git a/challenge-100/bob-lied/perl/ch-1.pl b/challenge-100/bob-lied/perl/ch-1.pl
new file mode 100755
index 0000000000..1016be7c42
--- /dev/null
+++ b/challenge-100/bob-lied/perl/ch-1.pl
@@ -0,0 +1,69 @@
+#!/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 100, TASK #1 › Fun Time
+#
+# You are given a time (12 hour / 24 hour).
+# Write a script to convert the given time from 12 hour format to 24 hour format and vice versa.
+# Ideally we expect a one-liner.
+# Example 1: Input: 05:15 pm or 05:15pm Output: 17:15
+# Example 2: Input: 19:15 Output: 07:15 pm or 07:15pm
+# 
+#=============================================================================
+
+use strict;
+use warnings;
+use 5.020;
+use experimental qw/signatures/;
+
+use Getopt::Long;
+
+my $DoTest = 0;
+GetOptions('test' => \$DoTest);
+
+runTest() if $DoTest;
+
+for my $tstr ( @ARGV )
+{
+    say funTime($tstr);
+}
+
+sub funTime($t)
+{
+    my ($hr,$min) = $t =~ m/(\d{1,2}):(\d\d)/;
+    return "--:--" if ( $hr < 0 || $hr > 24 || $min < 0 || $min > 59 );
+    my $suf;
+
+    if    ( $t =~ m/am/i ) { $suf = ""  ;                        }
+    elsif ( $t =~ m/pm/i ) { $suf = ""  ; $hr += 12 if $hr < 12; }
+    elsif ( $hr == 24 )    { $suf = "am"; $hr = 0;               }
+    elsif ( $hr == 12 )    { $suf = "pm";                        }
+    elsif ( $hr <  12 )    { $suf = "am";                        }
+    else                   { $suf = "pm"; $hr -= 12;             }
+
+    return sprintf "%02d:%02d%s", $hr, $min, $suf;
+}
+
+sub runTest
+{
+    use Test::More;
+    for my $case (
+                    ['05:15', '05:15am'],
+                    ['19:15', '07:15pm'],
+                    ['00:00', '00:00am'],
+                    ['11:15', '11:15am'],
+                    ['23:45', '11:45pm'],
+                    ['12:00', '12:00pm'],
+                 )
+    {
+        is( funTime($case->[0]), $case->[1] );
+        is( funTime($case->[1]), $case->[0] );
+    }
+    is( funTime("24:00"), "00:00am");
+
+    done_testing;
+}
diff --git a/challenge-100/bob-lied/perl/ch-2.pl b/challenge-100/bob-lied/perl/ch-2.pl
new file mode 100755
index 0000000000..720df96b95
--- /dev/null
+++ b/challenge-100/bob-lied/perl/ch-2.pl
@@ -0,0 +1,93 @@
+#!/usr/bin/env perl
+# vim:set ts=4 sw=4 sts=4 et ai wm=0 nu:
+#=============================================================================
+# ch-2.pl
+#=============================================================================
+# Copyright (c) 2021, Bob Lied
+#=============================================================================
+# Perl Weekly Challenge 100, Task #2 › Triangle Sum
+#
+# You are given triangle array.
+# Write a script to find the minimum path sum from top to bottom.
+#
+# When you are on index i on the current row then you may move to either index
+# i or index i + 1 on the next row.
+#
+# Example 1: Input: Triangle = [ [1], [2,4], [6,4,9], [5,1,7,2] ]
+#            Output: 8
+#
+# Explanation: The given triangle
+#
+#           1
+#          2 4
+#         6 4 9
+#        5 1 7 2
+# The minimum path sum from top to bottom:  1 + 2 + 4 + 1 = 8
+#=============================================================================
+
+use strict;
+use warnings;
+use 5.020;
+use experimental qw/ signatures /;
+
+use Getopt::Long;
+my $DoTest;
+my $Verbose;
+GetOptions('test' => \$DoTest, 'verbose' => \$Verbose);
+
+use List::Util qw(min);
+
+runTest() if $DoTest;
+
+my $minSum;
+sub walk($tree, $lastRow, $row, $col, $sum)
+{
+    say "WALK: lastRow=$lastRow, row=$row, col=$col, sum=$sum" if $Verbose;
+    if ( $row == $lastRow )
+    {
+        $minSum = min( ($minSum //= $sum), $sum);
+        say "LEAF: row=$row, col=$col, sum=$sum: minSum=$minSum" if $Verbose;
+        return $sum;
+    }
+
+    walk($tree, $lastRow, $row+1, $col,   $sum + $tree->[$row+1][$col]  );
+    walk($tree, $lastRow, $row+1, $col+1, $sum + $tree->[$row+1][$col+1]);
+
+    return $sum;
+}
+sub triangleSum($tri)
+{
+    $minSum = undef;
+    my $lastRow = @$tri - 1;
+
+    if ( $lastRow > 0 )
+    {
+        walk($tri, $lastRow, 1, 0, $tri->[0][0] + $tri->[1][0]) ;
+        walk($tri, $lastRow, 1, 1, $tri->[0][0] + $tri->[1][1]) ;
+    }
+    else
+    {
+        $minSum = $tri->[0][0];
+    }
+
+    return $minSum;
+}
+
+sub runTest
+{
+    use Test::More;
+
+    for my $case (
+        [  [ [9] ]  , 9 ],
+        [  [ [2], [3,5] ]  , 5 ],
+        [  [ [1], [2,4], [6,4,9]  ]            , 7 ],
+        [  [ [1], [2,4], [6,4,9], [5,1,7,2] ]  , 8 ],
+        [  [ [3], [3,1], [5,2,3], [4,3,1,3] ]  , 7 ],
+                 )
+    {
+        is ( triangleSum($case->[0]), $case->[1] );
+    }
+
+    done_testing;
+}
+