Week 208 task 1

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+#!/usr/bin/env perl
+# vim:set ts=4 sw=4 sts=4 et ai wm=0 nu:
+#=============================================================================
+# ch-1.pl Perl Weekly Challenge Week 208 Task 1 Minimum Index Sum 
+#=============================================================================
+# Copyright (c) 2023, Bob Lied
+#=============================================================================
+# You are given two arrays of strings.
+# Write a script to find out all common strings in the given two arrays with
+# minimum index sum. If no common strings found returns an empty list.
+# Example 1 Input: @list1 = ("Perl", "Raku", "Love")
+#                  @list2 = ("Raku", "Perl", "Hate")
+#          Output: ("Perl", "Raku")
+#   There are two common strings "Perl" and "Raku".
+#   Index sum of "Perl": 0 + 1 = 1
+#   Index sum of "Raku": 1 + 0 = 1
+# Example 2 Input: @list1 = ("A", "B", "C")
+#                  @list2 = ("D", "E", "F")
+#          Output: ()
+#   No common string found, so no result.
+# Example 3 Input: @list1 = ("A", "B", "C")
+#                  @list2 = ("C", "A", "B")
+#          Output: ("A")
+#   There are three common strings "A", "B" and "C".
+#   Index sum of "A": 0 + 1 = 1
+#   Index sum of "B": 1 + 2 = 3
+#   Index sum of "C": 2 + 0 = 2
+#=============================================================================
+
+use v5.36;
+
+use List::Util qw/min/;
+
+use Getopt::Long;
+my $Verbose = 0;
+my $DoTest  = 0;
+
+GetOptions("test" => \$DoTest, "verbose" => \$Verbose);
+exit(!runTest()) if $DoTest;
+
+#########
+# Command line 
+#########
+use feature 'try'; no warnings "experimental::try";
+my @list1 = ();
+my @list2 = ();
+try
+{
+    @list1 = defined $ARGV[0] && split(/[ ,]/, $ARGV[0]);
+    @list2 = defined $ARGV[1] && split(/[ ,]/, $ARGV[1]);
+}
+catch ($e) {
+    say "Caught: ", $e;
+}
+
+say "LIST1: [@list1]\nLIST2: [@list2]" if $Verbose;
+
+say "(", join(",", map { qq("$_") } minIndexSum(\@list1, \@list2)->@*), ")";
+
+# Convert a list to an index lookup hash.  Example:
+#   [ a, b ]  becomes  { a => 0, b => 1 }
+sub asHash($list)
+{
+    my %h = map { $list->[$_] => $_ } 0 .. $#{$list};
+    return \%h;
+}
+
+sub minIndexSum($list1, $list2)
+{
+    my @result;
+
+    my ($h1, $h2) = ( asHash($list1), asHash($list2) );
+
+    my %indexSum = map { $_ => ( $h1->{$_} + $h2->{$_} ) }
+                            grep { exists $h2->{$_} } keys %$h1;
+
+    my $min = min(values %indexSum);
+
+    @result = grep { $indexSum{$_} == $min } keys %indexSum;
+
+    return \@result;
+}
+
+sub runTest
+{
+    use Test2::V0;
+
+    is( minIndexSum( [ qw(Perl Raku Love) ], [ qw(Raku Perl Hate) ] ),
+            [ qw(Perl Raku) ], "Example 1");
+
+    is( minIndexSum( [ qw(A B C) ], [ qw(D E F) ] ), [], "Example 2");
+
+    is( minIndexSum( [ qw(A B C) ], [ qw(C A B) ] ), [ "A" ], "Example 3");
+
+    is( minIndexSum( [ ], [ qw(A B C) ] ), [], "list 1 empty");
+    is( minIndexSum( [ qw(A B C) ], [ ] ), [], "list 2 empty");
+    is( minIndexSum( [ ], [ ] ), [], "both lists empty");
+
+    done_testing;
+}
+