Solutions for challange 211

2 files changed, 132 insertions, 0 deletions

diff --git a/challenge-211/peter-meszaros/perl/ch-1.pl b/challenge-211/peter-meszaros/perl/ch-1.pl
new file mode 100755
index 0000000000..41ac51a6c5
--- /dev/null
+++ b/challenge-211/peter-meszaros/perl/ch-1.pl
@@ -0,0 +1,51 @@
+#!/usr//bin/perl
+# Example 1
+# 
+# Input: @matrix = [ [4, 3, 2, 1],
+#                    [5, 4, 3, 2],
+#                    [6, 5, 4, 3],
+#                  ]
+# Output: true
+# 
+# Example 2
+# 
+# Input: @matrix = [ [1, 2, 3],
+#                    [3, 2, 1],
+#                  ]
+# Output: false
+
+use strict;
+use warnings;
+use Test::More;
+
+my $cases = [
+	[[4, 3, 2, 1],
+	 [5, 4, 3, 2],
+	 [6, 5, 4, 3],
+	],
+	[[1, 2, 3],
+	 [3, 2, 1],
+	],
+];
+
+sub is_toeplitz
+{
+	my $mref = shift;
+
+    my $m = $mref->@* - 1;
+    my $n = $mref->[0]->@* - 1;
+    for(my $i=0; $i < $m; ++$i) {
+		for(my $j=0; $j < $n; ++$j) {
+			return 0 if ($mref->[$i]->[$j] != $mref->[$i + 1][$j + 1]);
+		}
+	}
+
+	return 1;
+}
+
+is(is_toeplitz($cases->[0]), 1, 'Toeplitz');
+is(is_toeplitz($cases->[1]), 0, 'Non-Toeplitz');
+done_testing();
+
+exit 0;
+
diff --git a/challenge-211/peter-meszaros/perl/ch-2.pl b/challenge-211/peter-meszaros/perl/ch-2.pl
new file mode 100755
index 0000000000..470ed3ca42
--- /dev/null
+++ b/challenge-211/peter-meszaros/perl/ch-2.pl
@@ -0,0 +1,81 @@
+#!/usr//bin/perl
+# Example 1:
+# 
+# Input: @nums = (1, 2, 3, 4, 5, 6, 7, 8)
+# Output: true
+# 
+# We can split the given array into (1, 4, 5, 8) and (2, 3, 6, 7).
+# The average of the two arrays are the same i.e. 4.5.
+# 
+# Example 2:
+# 
+# Input: @list = (1, 3)
+# Output: false
+
+use strict;
+use warnings;
+use List::Util qw/sum0/;
+use Test::More;
+
+my $cases = [
+    [1, 2, 3, 4, 5, 6, 7, 8],
+    [1, 3],
+];
+
+sub avg
+{
+	my $a = shift;
+	return sum0(@$a) / @$a;
+}
+
+sub combine
+{
+  my ($list, $n) = @_;
+  die "Insufficient list members" if $n > @$list;
+
+  return map [$_], @$list if $n <= 1;
+
+  my @comb;
+
+  for (my $i = 0; $i+$n <= @$list; ++$i) {
+    my $val  = $list->[$i];
+    my @rest = @$list[$i+1..$#$list];
+    push @comb, [$val, @$_] for combine(\@rest, $n-1);
+  }
+
+  return @comb;
+}
+
+sub split_array
+{
+	my $lref = shift;
+
+    my $idx = [0..$#$lref];
+	my @idxlist;
+	my $n = 0;
+	while ($n < int(@$idx / 2)) {
+		push @idxlist, combine($idx, ++$n);
+	}
+
+	for my $i (@idxlist) {
+		my @l = $lref->@[@$i];
+		my @r = @$lref;
+		delete @r[@$i];
+        @r = grep { defined } @r;
+        my $lavg = avg(\@l);
+        my $ravg = avg(\@r);
+        if (abs($lavg - $ravg) < 0.001) {
+			#print join('|', @$i), '--', join('|', @l), ' - ', join('|', @r),
+			#	' -> ', $lavg, '<=>', $ravg, "\n";
+			return 1
+		}
+    }
+	return 0;
+}
+
+is(split_array($cases->[0]), 1, '[1, 2, 3, 4, 5, 6, 7, 8]');
+is(split_array($cases->[1]), 0, '[1, 3]');
+done_testing();
+
+exit 0;
+