7 files changed, 69 insertions, 29 deletions
diff --git a/challenge-074/bob-lied/README b/challenge-074/bob-lied/README
index 289b995df4..e3712fbb10 100644
--- a/challenge-074/bob-lied/README
+++ b/challenge-074/bob-lied/README
@@ -6,8 +6,12 @@ https://perlweeklychallenge.org/blog/perl-weekly-challenge-074/
 
 ** Initial thoughts
 
+This is going to be an exercise in hashes and grep.
+
 ** Post Solution Thoughts
 
+Use a hash to count to count elements, then use grep with a code block to select the match.
+
 ** Problem Statement
 
 You are given an array of integers of size $N.
@@ -20,8 +24,19 @@ Majority element in the list is the one that appears more than floor(size_of_lis
 
 ** Initial Thoughts
 
+The specification is a little odd and doesn't match the example.  But, OK, whatever.
+Similar to the first task, another hash to count occurrences and grep to find the answers.
+
 ** Post Solution Thoughts
 
+Going through the string could be either done with substr one character at a time,
+or splitting the string into an array of characters.  Finding the first char could be
+a search through the character positions, or a sort and picking off the first element.
+Sort is the easy answer, but I'm always wary of scaling.  Like in many of these
+problems, it's not an issue for "reasonable" strings, but could become a performance
+question if the strings were a thousand or a million times bigger.
+
+
 ** Problem Statement
 
 You are given a string $S.
diff --git a/challenge-074/bob-lied/perl/ch-1.pl b/challenge-074/bob-lied/perl/ch-1.pl
index 57201dd4ff..fd0a1a51ee 100644
--- a/challenge-074/bob-lied/perl/ch-1.pl
+++ b/challenge-074/bob-lied/perl/ch-1.pl
@@ -9,11 +9,17 @@
 #=============================================================================
 # You are given an array of integers of size $N.
 # Write a script to find the majority element.  If none found, then print -1.
-# Majority element in the list is th one that appears more than floor($N/2).
+# Majority element in the list is the one that appears more than floor($N/2).
 
 use strict;
 use warnings;
+use feature qw(say);
 
 use lib "lib";
 use MajorityElement;
 
+my @ARR = @ARGV;
+
+die "Give a list of integers" unless @ARR;
+
+say majorityElement(@ARR);
diff --git a/challenge-074/bob-lied/perl/ch-2.pl b/challenge-074/bob-lied/perl/ch-2.pl
index 64b3a88739..6dbfa34667 100644
--- a/challenge-074/bob-lied/perl/ch-2.pl
+++ b/challenge-074/bob-lied/perl/ch-2.pl
@@ -17,10 +17,19 @@
 # Pass 2: "ab"    the FNR is 'b'
 # Pass 3: "aba"   the FNR is 'b'
 # Pass 4: "abab"  the FNR is '#' (all chars repeat)
-# Pass 5: "ababc" then FNR is 'c'
+# Pass 5: "ababc" the FNR is 'c'
+#
+# Note that this example is actually taking the right-most character as
+# the first non-repeater, which is counter-intuitive to the specification.
 
 use strict;
 use warnings;
 
 use lib "lib";
+use FNR qw(firstNonRepeat);
 
+my $S = shift;
+
+die "Need a string" unless $S;
+
+say firstNonRepeat($S);
diff --git a/challenge-074/bob-lied/perl/lib/FNR.pm b/challenge-074/bob-lied/perl/lib/FNR.pm
index c0cbae378d..ba53ff2f68 100644
--- a/challenge-074/bob-lied/perl/lib/FNR.pm
+++ b/challenge-074/bob-lied/perl/lib/FNR.pm
@@ -4,7 +4,7 @@
 #=============================================================================
 # Copyright (c) 2020, Bob Lied
 #=============================================================================
-# Description:
+# Description: 
 #=============================================================================
 
 package FNR;
@@ -14,24 +14,27 @@ use warnings;
 
 require Exporter;
 our @ISA = qw(Exporter);
-our @EXPORT = qw();
+our @EXPORT = qw(firstNonRepeat);
 our @EXPORT_OK = qw();
 
-sub new
-{
-    my $class = shift;
-    my $class = ref($class) || $class;
-    my $self = {
-        _name1 = $_[0],
-    };
-    bless $self, $class;
-    return $self;
-}
-
-sub FNR
+sub firstNonRepeat
 {
     my ($s) = @_;
     my $result = "";
+    my %charData;   # Save position and count of letters
+
+    for my $i ( 0 .. length($s)-1 )
+    {
+        my $char = substr($s, $i, 1);
+        $charData{$char}{cnt}++;
+        $charData{$char}{pos} = $i unless exists $charData{$char}{pos};
+
+        # Select non-repeating characters and sort by position
+        my @nr = sort { $charData{$a}{pos} lt $charData{$b}{pos} }
+                    grep { $charData{$_}{cnt} == 1 } keys %charData;
+
+        $result .= $nr[0] // '#';
+    }
 
     return $result;
 }
diff --git a/challenge-074/bob-lied/perl/lib/MajorityElement.pm b/challenge-074/bob-lied/perl/lib/MajorityElement.pm
index 8a7dcb0192..a5c91ece97 100644
--- a/challenge-074/bob-lied/perl/lib/MajorityElement.pm
+++ b/challenge-074/bob-lied/perl/lib/MajorityElement.pm
@@ -17,21 +17,18 @@ our @ISA = qw(Exporter);
 our @EXPORT = qw(majorityElement);
 our @EXPORT_OK = qw();
 
-sub new
-{
-    my $class = shift;
-    my $class = ref($class) || $class;
-    my $self = {
-        _name1 = $_[0],
-    };
-    bless $self, $class;
-    return $self;
-}
-
 sub majorityElement
 {
     my (@arr) = @_;
     my $result = -1;
+    my %presence;
+    my $majorityThreshold = int(scalar(@arr)/2);
+
+    # Count the repetitions.
+    $presence{$_}++ foreach @arr;
+
+    # Select the one that passes the threshold.  There can only be one or none.
+    $result = (grep { $presence{$_} > $majorityThreshold } keys %presence)[0] // -1;
 
     return $result;
 }
diff --git a/challenge-074/bob-lied/perl/t/FNR.t b/challenge-074/bob-lied/perl/t/FNR.t
index 1d4fdd9472..dab6d0d82d 100644
--- a/challenge-074/bob-lied/perl/t/FNR.t
+++ b/challenge-074/bob-lied/perl/t/FNR.t
@@ -8,7 +8,13 @@ use warnings;
 
 use Test2::V0;
 
-use lib "../lib";
 use FNR;
 
+is( firstNonRepeat('ababc'),
+                   'abb#c',    "Example 1");
+is( firstNonRepeat('xyzzyx'),
+                   'xyzyx#', "Example 2 as given");
+#is( firstNonRepeat('xyzzyx'),
+#                   'xxxxx#', "Example 2 as specified");
+
 done_testing();
diff --git a/challenge-074/bob-lied/perl/t/MajorityElement.t b/challenge-074/bob-lied/perl/t/MajorityElement.t
index 7d1b4a22d8..e6d825cd38 100644
--- a/challenge-074/bob-lied/perl/t/MajorityElement.t
+++ b/challenge-074/bob-lied/perl/t/MajorityElement.t
@@ -8,7 +8,11 @@ use warnings;
 
 use Test2::V0;
 
-use lib "../lib";
 use MajorityElement;
 
+is( majorityElement(1,2,2,3,2,4,2),  2, "Example 1");
+is( majorityElement(1,3,1,2,4,5),   -1, "Example 2");
+
+is( majorityElement(1),              1, "Single element");
+
 done_testing();