Create ch-1.pl

1 files changed, 48 insertions, 0 deletions

diff --git a/challenge-208/james-smith/perl/ch-1.pl b/challenge-208/james-smith/perl/ch-1.pl
new file mode 100644
index 0000000000..f33c93686f
--- /dev/null
+++ b/challenge-208/james-smith/perl/ch-1.pl
@@ -0,0 +1,48 @@
+#!/usr/local/bin/perl
+
+use strict;
+use warnings;
+use feature qw(say);
+use Test::More;
+
+my @TESTS = (
+ [ [qw(Perl Raku Love)], [qw(Raku Perl Hate)], 'Perl Raku' ],
+ [ [qw(A B C)],          [qw(D E F)         ], ''             ],
+ [ [qw(A B C)],          [qw(C A B)         ], 'A' ],
+ [ [qw(A B C D E F)],    [qw(A B C)         ], 'A' ],
+ [ [qw(A B C)],          [qw(D E F G H C)   ], 'C' ],
+ [ ['A'..'Z'],           [reverse('A'..'Z')],  "@{[ 'A'..'Z' ]}" ],
+ [ ['A'..'Z'],           ['A'..'Z'],           'A' ],
+ [ ['A'..'Z'],           ['a'..'z'],           '' ],
+);
+
+is( min_index_sum(       @{$_->[0]} ), $_->[1] ) for @TESTS;
+is( min_index_sum_sweep( @{$_->[0]} ), $_->[1] ) for @TESTS;
+done_testing();
+
+sub min_index_sum {
+  my($b,%x,$t,$s,@best) =(1e99, map { $_[0][$_] => $_ } 0 .. $#{$_[0]});
+  exists $x{$t = $_[1][$_]} && (
+    $b > ($s=$x{$t}+$_) ? ($b,@best) = ( ($s,$t) )
+                   : ($b == $s )
+  ) && push @best, $t for 0 .. $#{$_[1]};
+  return \@best;
+}
+
+sub min_index_sum_sweep {
+  my($l1,$l2,@best)=@_;
+  ($l1,$l2)=($l2,$l1) if $#$l1 > $#$l2;
+  for my $l ( 0 .. $#$l1) {
+    ( $l1->[$_] eq $l2->[$l-$_] ) && (push @best, $l1->[$_]) for 0..$l;
+    return \@best if @best;
+  }
+  for my $l ( $#$l1+1 .. $#$l2 ) {
+    ( $l1->[$_] eq $l2->[$l-$_] ) && (push @best, $l1->[$_]) for 0..$#$l1;
+    return \@best if @best;
+  }
+  for my $l ( $#$l2+1 .. $#$l2+$#$l1 ) {
+    ( $l1->[$_] eq $l2->[$l-$_] ) && (push @best, $l1->[$_]) for ($l-$#$l2)..$#$l1;
+    return \@best if @best;
+  }
+  return [];
+}