Merge pull request #1562 from jaredor/new-branch

update to ch-2.pl

3 files changed, 120 insertions, 0 deletions

diff --git a/challenge-055/jaredor/README b/challenge-055/jaredor/README
new file mode 100644
index 0000000000..398fcc9bae
--- /dev/null
+++ b/challenge-055/jaredor/README
@@ -0,0 +1 @@
+Solution by Jared Martin
diff --git a/challenge-055/jaredor/perl/ch-1.pl b/challenge-055/jaredor/perl/ch-1.pl
new file mode 100755
index 0000000000..c548450d8c
--- /dev/null
+++ b/challenge-055/jaredor/perl/ch-1.pl
@@ -0,0 +1,46 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use List::Util qw(sum max);
+use List::MoreUtils qw(indexes);
+
+my $binstr = $ARGV[0];
+
+die "Need a string of 0s and 1s, not this: -->$binstr<--\n"
+  if $binstr !~ /\A [01]+ \Z/xms;
+
+my ( $begstr, $midstr, $endstr ) = ( $binstr, '', '' );
+( $begstr, $midstr, $endstr ) = ( $binstr =~ /\A(1*)(.*0)(1*)\Z/xms )
+  if $binstr =~ /0/;
+
+my $i = 0;
+my @groups =
+  map { ( /0/ ? 1 : -1 ) * length($_) }
+  grep { $i = !$i } ( $midstr =~ /((.)\g{-1}*)/g );
+
+my ( $L, $max ) = ( length($begstr), 0 );
+my @answers;
+while (@groups) {
+    my $total = 0;
+    my @tot = map { $total += $_ } @groups; # List::Util reductions
+    $max = max( $max, max @tot );
+    for my $idx (indexes { $_ == $max } @tot) {
+        my $R = -1 + sum map { abs $_ } $L, @groups[ 0 .. $idx ];
+        push @answers, [ $L, $R, $max];
+    }
+    $L += sum map { abs $_ } splice(@groups, 0, 2);
+}
+@answers = grep { pop @$_ == $max } @answers;
+
+my $header1 = "INPUT STRING : $binstr";
+print "\n$header1\n\n";
+
+my $header2 = 'Maximal Flip Pairs';
+print "$header2\n", '.' x length $header2, "\n";
+print "NONE\n" unless @answers;
+
+while (@answers) {
+    my ( $L, $R, $flipped, ) = (@{ shift @answers }, $binstr);
+    substr( $flipped, $L, $R - $L + 1 ) =~ tr/01/10/;
+    print "(L=$L, R=$R) : $flipped\n";
+}
diff --git a/challenge-055/jaredor/perl/ch-2.pl b/challenge-055/jaredor/perl/ch-2.pl
new file mode 100755
index 0000000000..bd2b44c382
--- /dev/null
+++ b/challenge-055/jaredor/perl/ch-2.pl
@@ -0,0 +1,73 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use List::Util qw(sum max);
+use List::MoreUtils qw(indexes);
+
+# Command line input:
+#
+#    EITHER:
+#       * One string of the form, '[ ###, ###, ..., ### ]'
+#         Where brackets are optional and the numbers just
+#         need to be space or comma delimited.
+#
+#       * A list of numeric arguments.
+#
+my @narray;
+if ( @ARGV == 1 ) {
+    my $str = $ARGV[0];
+    $str =~ tr/][,/   /;
+    @narray = sort { $b <=> $a } grep { /\A -? \d* \.? \d+ \Z/xms } split /\s+/,
+      $str;
+}
+else {
+    @narray = sort { $b <=> $a } @ARGV;
+}
+
+sub foo {
+    my ( $so_far, $pick_from, $the_rest ) = @_;
+    my @so_far    = @$so_far;
+    my @pick_from = @$pick_from;
+    my @the_rest  = @$the_rest;
+    if ( @pick_from == 0 ) {
+        print( '[', join( ', ', @so_far ), "]\n" ) unless @the_rest;
+        return;
+    }
+    else {
+        for my $i ( 0 .. $#pick_from ) {
+            my @tmp_so_far    = @so_far;
+            my @tmp_pick_from = @pick_from;
+            my @tmp_the_rest  = @the_rest;
+            push @tmp_so_far, $pick_from[$i];
+            my @pick_from_prev = @pick_from[ 0 .. $i ];
+            pop @pick_from_prev;
+            my @pick_from_post = @pick_from[ $i .. $#pick_from ];
+            shift @pick_from_post;
+            foo(
+                [@tmp_so_far],
+                [ reverse( @pick_from_post, @tmp_the_rest ) ],
+                [ reverse @pick_from_prev ],
+            );
+        }
+    }
+}
+
+if ( @narray > 1 ) {
+    for my $i ( 0 .. ( $#narray - 1 ) ) {
+        next if $i > 0 and $narray[$i] == $narray[ $i - 1 ];
+        my @so_far         = ( $narray[$i], );
+        my @pick_from_prev = @narray[ 0 .. $i ];
+        pop @pick_from_prev;
+        my @pick_from_post = @narray[ $i .. $#narray ];
+        shift @pick_from_post;
+        foo(
+            [@so_far],
+            [ reverse @pick_from_post ],
+            [ reverse @pick_from_prev ],
+        );
+    }
+}
+else {
+    print( '[', join( ', ', @narray ), "]\n" );
+}
+