From 8a3c526f23a8e173fa9a6d8344643ea4fa7d5738 Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 3 Apr 2023 10:41:41 +0200
Subject: Task 1 done

---
 challenge-211/luca-ferrari/raku/ch-1.p6 | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 challenge-211/luca-ferrari/raku/ch-1.p6

(limited to 'challenge-211')

diff --git a/challenge-211/luca-ferrari/raku/ch-1.p6 b/challenge-211/luca-ferrari/raku/ch-1.p6
new file mode 100644
index 0000000000..6c506c4842
--- /dev/null
+++ b/challenge-211/luca-ferrari/raku/ch-1.p6
@@ -0,0 +1,22 @@
+#!raku
+
+#
+# Perl Weekly Challenge 211
+# Task 1
+#
+# See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-211/>
+#
+
+sub MAIN() {
+
+    my @matrix = [ [4, 3, 2, 1],
+                   [5, 4, 3, 2],
+                   [6, 5, 4, 3],
+                 ];
+
+    my %diag;
+    %diag{ @matrix[ $_ ][ $_ ] }++ for 0 ..^ @matrix.elems;
+    'False'.say if ( %diag.keys.elems != 1 || %diag{ @matrix[ 0 ][ 0 ] } != @matrix.elems );
+    'True'.say;
+
+}
-- 
cgit 


From 01b9182fbd76e758dc13ea9706ea714612cdf98a Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 3 Apr 2023 11:40:59 +0200
Subject: Task 2 done

---
 challenge-211/luca-ferrari/raku/ch-2.p6 | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 challenge-211/luca-ferrari/raku/ch-2.p6

(limited to 'challenge-211')

diff --git a/challenge-211/luca-ferrari/raku/ch-2.p6 b/challenge-211/luca-ferrari/raku/ch-2.p6
new file mode 100644
index 0000000000..e7a81ce359
--- /dev/null
+++ b/challenge-211/luca-ferrari/raku/ch-2.p6
@@ -0,0 +1,20 @@
+#!raku
+
+#
+# Perl Weekly Challenge 211
+# Task 2
+#
+# See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-211/>
+#
+
+sub MAIN( *@list where{ @list.elems == @list.grep( * ~~ Int ).elems } ) {
+
+    for @list.permutations -> @current {
+	for 0 ..^ @current.elems {
+	    my ($left, $right) = @current[ 0 .. $_ ], @current[ $_ + 1 .. * - 1 ];
+	    if ( ( $left.sum / $left.elems ) == ( $right.sum / $right.elems ) ) {
+		exit;
+	    }
+	}
+    }
+}
-- 
cgit 


From 2773e3648994354fc169f59fa8dd148aacf96100 Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 3 Apr 2023 11:51:31 +0200
Subject: Task 1 plperl done

---
 challenge-211/luca-ferrari/postgresql/ch-1.plperl | 29 +++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 challenge-211/luca-ferrari/postgresql/ch-1.plperl

(limited to 'challenge-211')

diff --git a/challenge-211/luca-ferrari/postgresql/ch-1.plperl b/challenge-211/luca-ferrari/postgresql/ch-1.plperl
new file mode 100644
index 0000000000..d2085bdc4c
--- /dev/null
+++ b/challenge-211/luca-ferrari/postgresql/ch-1.plperl
@@ -0,0 +1,29 @@
+--
+-- Perl Weekly Challenge 211
+-- Task 1
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-211/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc211;
+
+/*
+testdb=> select pwc211.task1_plperl( array[ array[4,3,2,1], array[ 5,4,3,2], array[6,5,4,3] ] );
+ task1_plperl 
+--------------
+ t
+(1 row)
+
+*/
+CREATE OR REPLACE FUNCTION
+pwc211.task1_plperl( int[][] )
+RETURNS bool
+AS $CODE$
+   my ( $array ) = @_;
+
+   my $diag;
+   $diag->{ $array->[ $_ ]->[ $_ ] }++ for ( 0 .. scalar( $array->@* ) - 1 );
+   return 0 if ( keys( $diag->%* ) != 1 );
+   return 0 if ( $diag->{ $array->[ 0 ]->[ 0 ] } != scalar( $array->@* ) );
+   return 1;
+$CODE$
+LANGUAGE plperl;
-- 
cgit 


From 1bab1d6247beb4ed475992cc978e74cff4b654f7 Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 3 Apr 2023 12:10:59 +0200
Subject: Task 2 done with equally sized arrays

---
 challenge-211/luca-ferrari/raku/ch-2.p6 | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

(limited to 'challenge-211')

diff --git a/challenge-211/luca-ferrari/raku/ch-2.p6 b/challenge-211/luca-ferrari/raku/ch-2.p6
index e7a81ce359..aa425afa73 100644
--- a/challenge-211/luca-ferrari/raku/ch-2.p6
+++ b/challenge-211/luca-ferrari/raku/ch-2.p6
@@ -10,11 +10,21 @@
 sub MAIN( *@list where{ @list.elems == @list.grep( * ~~ Int ).elems } ) {
 
     for @list.permutations -> @current {
-	for 0 ..^ @current.elems {
-	    my ($left, $right) = @current[ 0 .. $_ ], @current[ $_ + 1 .. * - 1 ];
-	    if ( ( $left.sum / $left.elems ) == ( $right.sum / $right.elems ) ) {
-		exit;
-	    }
+	# for 0 ..^ @current.elems {
+	#     # find the first couple that gives the same average
+	#     my ($left, $right) = @current[ 0 .. $_ ], @current[ $_ + 1 .. * ];
+	#     if ( ( $left.sum / $left.elems ) == ( $right.sum / $right.elems ) ) {
+	# 	say "{ $left.join( ',' ) } = { $left.sum / $left.elems }  and { $right.join( ',' ) } = { $right.sum / $right.elems } ";
+	# 	exit;
+	#     }
+	# }
+
+	my $split-at = ( @current.elems - 1 ) / 2;
+	my ($left, $right) = @current[ 0 .. $split-at ], @current[ $split-at + 1  .. *  ];
+	if ( ( $left.sum / $left.elems ) == ( $right.sum / $right.elems ) ) {
+	    say "{ $left.join( ',' ) } = { $left.sum / $left.elems }  and { $right.join( ',' ) } = { $right.sum / $right.elems } ";
+	    exit;
 	}
+
     }
 }
-- 
cgit 


From c523fbd673bd6651db49e4c1a97908687a9fa035 Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 3 Apr 2023 12:18:58 +0200
Subject: Task 2 plperl done

---
 challenge-211/luca-ferrari/postgresql/ch-2.plperl | 40 +++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 challenge-211/luca-ferrari/postgresql/ch-2.plperl

(limited to 'challenge-211')

diff --git a/challenge-211/luca-ferrari/postgresql/ch-2.plperl b/challenge-211/luca-ferrari/postgresql/ch-2.plperl
new file mode 100644
index 0000000000..6513b34abf
--- /dev/null
+++ b/challenge-211/luca-ferrari/postgresql/ch-2.plperl
@@ -0,0 +1,40 @@
+--
+-- Perl Weekly Challenge 211
+-- Task 2
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-211/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc211;
+
+/*
+estdb=# select pwc211.task2_plperl( array[ 1,2,3,4,5,6,7,8] );
+ task2_plperl 
+--------------
+ {1,2,7,8}
+ {3,4,5,6}
+(2 rows)
+
+*/
+CREATE OR REPLACE FUNCTION
+pwc211.task2_plperl( int[] )
+RETURNS SETOF int[]
+AS $CODE$
+   use List::Permutor;
+   use List::Util qw/sum/;
+   my ( $array ) = @_;
+
+   my $permutator   = List::Permutor->new( $array->@* );
+   while ( my @current = $permutator->next ) {
+     my ( $split_at ) = ( $#current + 1) / 2;
+     my ( $left, $right ) = ( [ @current[ 0 .. ( $split_at - 1 ) ] ], [ @current[ $split_at .. $#current ] ] );
+
+     if ( ( sum( $left->@* ) / scalar( $left->@* ) ) == ( sum( $right->@* ) / scalar( $right->@* ) ) ) {
+     	return_next( $left );
+	return_next( $right );
+	return undef;
+     }
+   }
+
+return undef;
+$CODE$
+LANGUAGE plperlu;
-- 
cgit 


From ff22c74e122711797e658d51ff3e5bd17ad66a8d Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 3 Apr 2023 12:32:25 +0200
Subject: Task 1 plpgsql

---
 challenge-211/luca-ferrari/postgresql/ch-1.sql | 36 ++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 challenge-211/luca-ferrari/postgresql/ch-1.sql

(limited to 'challenge-211')

diff --git a/challenge-211/luca-ferrari/postgresql/ch-1.sql b/challenge-211/luca-ferrari/postgresql/ch-1.sql
new file mode 100644
index 0000000000..23a33447de
--- /dev/null
+++ b/challenge-211/luca-ferrari/postgresql/ch-1.sql
@@ -0,0 +1,36 @@
+--
+-- Perl Weekly Challenge 211
+-- Task 1
+--
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-211/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc211;
+
+CREATE OR REPLACE FUNCTION
+pwc211.task1_plpgsql( a int[][])
+RETURNS bool
+AS $CODE$
+DECLARE
+	current_row  int := 1;
+	current_col  int := 1;
+	previous_val int := NULL;
+BEGIN
+	WHILE current_row <= array_length( a, 1 ) LOOP
+	      IF current_row > array_length( a, 2 ) THEN
+	      	 RETURN false;
+              END IF;
+
+	      IF previous_val IS NULL THEN
+	      	 previous_val := a[ current_row ][ current_row ];
+	      ELSIF previous_val <> a[ current_row ][ current_row ] THEN
+	      	   RETURN false;
+             END IF;
+
+	     current_row := current_row + 1;
+	END LOOP;
+
+	RETURN true;
+END
+$CODE$
+LANGUAGE plpgsql;
-- 
cgit 


From 765e35de7cb90dab45fea9c6a5c15c66e99a934f Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 3 Apr 2023 13:24:53 +0200
Subject: Task 2 plpgsql done

---
 challenge-211/luca-ferrari/postgresql/ch-2.sql | 65 ++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 challenge-211/luca-ferrari/postgresql/ch-2.sql

(limited to 'challenge-211')

diff --git a/challenge-211/luca-ferrari/postgresql/ch-2.sql b/challenge-211/luca-ferrari/postgresql/ch-2.sql
new file mode 100644
index 0000000000..802a8f6932
--- /dev/null
+++ b/challenge-211/luca-ferrari/postgresql/ch-2.sql
@@ -0,0 +1,65 @@
+--
+-- Perl Weekly Challenge 211
+-- Task 2
+--
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-211/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc211;
+
+-- see <https://wiki.postgresql.org/wiki/Permutations>
+CREATE FUNCTION pwc211.permute(anyarray)
+  RETURNS SETOF anyarray
+  LANGUAGE SQL IMMUTABLE
+AS $f$
+  SELECT (WITH RECURSIVE r(n,p,a,b)
+               AS (SELECT i, $1[1:0], $1, array_upper($1,1)
+                   UNION ALL
+                   SELECT n / b, p || a[n % b + 1], a[1:n % b] || a[n % b + 2:b], b-1
+                     FROM r
+                    WHERE b > 0)
+          SELECT p FROM r WHERE b=0)
+  FROM generate_series(0,factorial( (array_upper($1,1)) )::integer-1) i;
+$f$;
+
+
+
+
+CREATE OR REPLACE FUNCTION
+pwc211.task2_plpgsql( a int[] )
+RETURNS SETOF int[]
+AS $CODE$
+DECLARE
+	split_at int := 0;
+	current_array int[];
+	l int[];
+	r int [];
+	avg_l numeric;
+	avg_r numeric;
+BEGIN
+	split_at := array_length( a, 1 ) / 2;
+
+	FOR current_array IN SELECT * FROM pwc211.permute( a ) LOOP
+	    l := current_array[ 1:split_at ];
+	    r := current_array[ (split_at + 1): array_length( a, 1 ) ];
+
+
+	    SELECT avg( v )
+	    INTO   avg_l
+	    FROM   unnest( l ) v;
+
+	    SELECT avg( v )
+	    INTO   avg_r
+	    FROM   unnest( r ) v;
+
+	    IF avg_r = avg_l THEN
+	       RETURN NEXT l;
+	       RETURN NEXT r;
+	       RETURN;
+	    END IF;
+	END LOOP;
+
+RETURN;
+END
+$CODE$
+LANGUAGE plpgsql;
-- 
cgit 


From c3fd6bcfdd91b1b27e25b5949c82d0bfd2303d00 Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 3 Apr 2023 13:38:26 +0200
Subject: Blog references

---
 challenge-211/luca-ferrari/blog-1.txt | 1 +
 challenge-211/luca-ferrari/blog-2.txt | 1 +
 challenge-211/luca-ferrari/blog-3.txt | 1 +
 challenge-211/luca-ferrari/blog-4.txt | 1 +
 challenge-211/luca-ferrari/blog-5.txt | 1 +
 challenge-211/luca-ferrari/blog-6.txt | 1 +
 6 files changed, 6 insertions(+)
 create mode 100644 challenge-211/luca-ferrari/blog-1.txt
 create mode 100644 challenge-211/luca-ferrari/blog-2.txt
 create mode 100644 challenge-211/luca-ferrari/blog-3.txt
 create mode 100644 challenge-211/luca-ferrari/blog-4.txt
 create mode 100644 challenge-211/luca-ferrari/blog-5.txt
 create mode 100644 challenge-211/luca-ferrari/blog-6.txt

(limited to 'challenge-211')

diff --git a/challenge-211/luca-ferrari/blog-1.txt b/challenge-211/luca-ferrari/blog-1.txt
new file mode 100644
index 0000000000..20aa3248b4
--- /dev/null
+++ b/challenge-211/luca-ferrari/blog-1.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2023/04/03/PerlWeeklyChallenge211.html#task1
diff --git a/challenge-211/luca-ferrari/blog-2.txt b/challenge-211/luca-ferrari/blog-2.txt
new file mode 100644
index 0000000000..af2ebde9dd
--- /dev/null
+++ b/challenge-211/luca-ferrari/blog-2.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2023/04/03/PerlWeeklyChallenge211.html#task2
diff --git a/challenge-211/luca-ferrari/blog-3.txt b/challenge-211/luca-ferrari/blog-3.txt
new file mode 100644
index 0000000000..26e77011ea
--- /dev/null
+++ b/challenge-211/luca-ferrari/blog-3.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2023/04/03/PerlWeeklyChallenge211.html#task1plperl
diff --git a/challenge-211/luca-ferrari/blog-4.txt b/challenge-211/luca-ferrari/blog-4.txt
new file mode 100644
index 0000000000..87794d6a99
--- /dev/null
+++ b/challenge-211/luca-ferrari/blog-4.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2023/04/03/PerlWeeklyChallenge211.html#task2plperl
diff --git a/challenge-211/luca-ferrari/blog-5.txt b/challenge-211/luca-ferrari/blog-5.txt
new file mode 100644
index 0000000000..45531804ca
--- /dev/null
+++ b/challenge-211/luca-ferrari/blog-5.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2023/04/03/PerlWeeklyChallenge211.html#task1plpgsql
diff --git a/challenge-211/luca-ferrari/blog-6.txt b/challenge-211/luca-ferrari/blog-6.txt
new file mode 100644
index 0000000000..534fca5816
--- /dev/null
+++ b/challenge-211/luca-ferrari/blog-6.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2023/04/03/PerlWeeklyChallenge211.html#task2plpgsql
-- 
cgit 


From b413d247da323881e60bf1c45506ba9273194874 Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 3 Apr 2023 13:04:10 +0000
Subject: Challenge 211 Solutions (Raku)

---
 challenge-211/mark-anderson/raku/ch-1.raku | 31 ++++++++++++++++++++++++++++++
 challenge-211/mark-anderson/raku/ch-2.raku | 22 +++++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 challenge-211/mark-anderson/raku/ch-1.raku
 create mode 100644 challenge-211/mark-anderson/raku/ch-2.raku

(limited to 'challenge-211')

diff --git a/challenge-211/mark-anderson/raku/ch-1.raku b/challenge-211/mark-anderson/raku/ch-1.raku
new file mode 100644
index 0000000000..43c6f09b02
--- /dev/null
+++ b/challenge-211/mark-anderson/raku/ch-1.raku
@@ -0,0 +1,31 @@
+#!/usr/bin/env raku
+use Test;
+
+ok  toeplitz([4, 3, 2, 1],
+             [5, 4, 3, 2],
+             [6, 5, 4, 3]);
+
+nok toeplitz([1, 2, 3],
+             [3, 2, 1]);
+
+ok  toeplitz([4, 3, 2, 1],
+             [5, 4, 3, 2],
+             [6, 5, 4, 3],
+             [7, 6, 5, 4],
+             [8, 7, 6, 5]);
+
+ok  toeplitz([1,2],
+             [2,1],
+             [3,2],
+             [4,3]);
+
+sub toeplitz(+@m)
+{
+    until @m.elems == 1
+    {
+        return False unless @m[0;^@m[0].end] eqv @m[1;1..@m[1].end];
+        shift @m
+    }
+
+    return True
+}
diff --git a/challenge-211/mark-anderson/raku/ch-2.raku b/challenge-211/mark-anderson/raku/ch-2.raku
new file mode 100644
index 0000000000..768d0a4f09
--- /dev/null
+++ b/challenge-211/mark-anderson/raku/ch-2.raku
@@ -0,0 +1,22 @@
+#!/usr/bin/env raku
+use Test;
+
+ok  split-same-avg(1,2,3,4,5,6,7,8); # [1 8] [5 4 6 3 7 2]
+nok split-same-avg(1,3);
+ok  split-same-avg(3,3,5,5,5,2,2,1); # [3 3 5 2] [2 5 5 1]
+nok split-same-avg(5,5,5,2,2,1); 
+
+sub split-same-avg(*@nums)
+{
+    for (0..@nums.end).combinations(1..(@nums.elems div 2)) -> @a
+    {
+        my @b = ((0..@nums.end) (-) @a).keys;
+
+        my @c = @nums[@a];
+        my @d = @nums[@b];
+
+        return True if (@c.sum / @c.elems) == (@d.sum / @d.elems)
+    }
+
+    return False
+}
-- 
cgit 


From ed49e15822bccd580f4a09da9ead6d52bc5d5d2a Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 3 Apr 2023 14:35:09 +0000
Subject: Challenge 211 Solutions (Raku)

---
 challenge-211/mark-anderson/raku/ch-1.raku | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

(limited to 'challenge-211')

diff --git a/challenge-211/mark-anderson/raku/ch-1.raku b/challenge-211/mark-anderson/raku/ch-1.raku
index 43c6f09b02..2b86bde846 100644
--- a/challenge-211/mark-anderson/raku/ch-1.raku
+++ b/challenge-211/mark-anderson/raku/ch-1.raku
@@ -21,11 +21,5 @@ ok  toeplitz([1,2],
 
 sub toeplitz(+@m)
 {
-    until @m.elems == 1
-    {
-        return False unless @m[0;^@m[0].end] eqv @m[1;1..@m[1].end];
-        shift @m
-    }
-
-    return True
+    @m[^@m.end;^@m[0].end] eqv @m[1..@m.end;1..@m[1].end]
 }
-- 
cgit 


From 7fa49d501285c4b19d15736339bb405993d5a6ee Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 3 Apr 2023 15:05:25 +0000
Subject: Challenge 211 Solutions (Raku)

---
 challenge-211/mark-anderson/raku/ch-2.raku | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

(limited to 'challenge-211')

diff --git a/challenge-211/mark-anderson/raku/ch-2.raku b/challenge-211/mark-anderson/raku/ch-2.raku
index 768d0a4f09..b6563db667 100644
--- a/challenge-211/mark-anderson/raku/ch-2.raku
+++ b/challenge-211/mark-anderson/raku/ch-2.raku
@@ -8,14 +8,14 @@ nok split-same-avg(5,5,5,2,2,1);
 
 sub split-same-avg(*@nums)
 {
-    for (0..@nums.end).combinations(1..(@nums.elems div 2)) -> @a
+    for (^@nums).combinations(1..(@nums.elems div 2)) -> @a is copy
     {
-        my @b = ((0..@nums.end) (-) @a).keys;
+        my @b = ((^@nums) (-) @a).keys;
 
-        my @c = @nums[@a];
-        my @d = @nums[@b];
+        @a = @nums[@a];
+        @b = @nums[@b];
 
-        return True if (@c.sum / @c.elems) == (@d.sum / @d.elems)
+        return True if (@a.sum / @a.elems) == (@b.sum / @b.elems)
     }
 
     return False
-- 
cgit 


From ae5883dd2325dc38e265798748779fdd19fe1195 Mon Sep 17 00:00:00 2001
From: David Ferrone <zapwai@gmail.com>
Date: Mon, 3 Apr 2023 21:17:23 -0400
Subject: Week 211

---
 challenge-211/zapwai/perl/ch-1.pl | 43 +++++++++++++++++++++++++++++++++++++++
 challenge-211/zapwai/perl/ch-2.pl | 41 +++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 challenge-211/zapwai/perl/ch-1.pl
 create mode 100644 challenge-211/zapwai/perl/ch-2.pl

(limited to 'challenge-211')

diff --git a/challenge-211/zapwai/perl/ch-1.pl b/challenge-211/zapwai/perl/ch-1.pl
new file mode 100644
index 0000000000..13352b3e29
--- /dev/null
+++ b/challenge-211/zapwai/perl/ch-1.pl
@@ -0,0 +1,43 @@
+use v5.30.0;
+my @matrix = ( [4, 3, 2, 1],
+	       [5, 4, 3, 2],
+	       [6, 5, 4, 3], );
+# my @matrix = ( [1, 2, 3],
+#                    [3, 2, 1],
+#                  );
+my $m = $#matrix + 1;
+my $n = $#{$matrix[0]} + 1;
+say "Input: \@matrix is";
+for my $i (0 .. $m - 1) {
+    print " ";
+    for my $j (0 .. $n - 1) {
+	print $matrix[$i][$j];
+    }
+    print "\n";
+}
+my $flag = 1;
+for my $i (0 .. $m - 2) {
+    if ($i == 0) {
+	for my $j (0 .. $n - 2) {
+	    $flag = 0 unless (const_diag($i,$j));
+	}
+    } else {
+	$flag = 0 unless (const_diag($i,0));	
+    }
+}
+print "\nOutput: ";
+if ($flag) {
+    say "True, the matrix is Toeplitz.";
+} else {
+    say "False, the matrix is not Toeplitz.";
+}
+sub const_diag {
+    my ($i,$j) = @_;
+    my $val = $matrix[$i][$j];
+    for my $s ($i .. $m - 1) {
+	last if (!defined $matrix[$s][$j]);
+	return 0 unless ($matrix[$s][$j] == $val);
+	$j++;
+    }
+    1
+}
diff --git a/challenge-211/zapwai/perl/ch-2.pl b/challenge-211/zapwai/perl/ch-2.pl
new file mode 100644
index 0000000000..c08d3f84b0
--- /dev/null
+++ b/challenge-211/zapwai/perl/ch-2.pl
@@ -0,0 +1,41 @@
+use v5.30.0;
+my @nums = (1 .. 8);
+#my @nums = (1, 3);
+say "Input: \@nums = (@nums)";
+my $ans;
+my @subarrays;
+my $exp = $#nums + 1;
+for (1 .. (2**$exp) - 2) {
+    my $binary_number = sprintf '%'.$exp.'b', $_;
+    my @pips = split "", $binary_number;
+    my (@part1, @part2);
+    for my $i (0 .. $#nums) {
+	if ($pips[$i] == 1) {
+	    push @part1, $nums[$i];
+	} else {
+	    push @part2, $nums[$i];	    
+	}
+    }
+    my ($avg1, $avg2);
+    for my $elem (@part1) {
+	$avg1 += $elem;
+    }
+    for my $elem (@part2) {
+	$avg2 += $elem;
+    }
+    $avg1 = $avg1 / ($#part1 + 1);
+    $avg2 = $avg2 / ($#part2 + 1);    
+    #    say "@part1 - @part2 ~ $avg1 - $avg2";
+    if ($avg1 - $avg2 == 0) {
+	$ans = 1;
+	my $str = "(@part1)" . ' & ' . "(@part2) with avg $avg1";
+	push @subarrays, $str;
+    }
+}
+print "Output: ";
+if ($ans) {
+    say "true";
+    say "e.g. $subarrays[0]";    
+} else {
+    say "false";
+}
-- 
cgit 


From 5235f58bcc290126d1d6974e85e6dfd13f4c2a37 Mon Sep 17 00:00:00 2001
From: Luis Mochan <mochan@fis.unam.mx>
Date: Mon, 3 Apr 2023 19:19:08 -0600
Subject: Solve PWC211

---
 challenge-211/wlmb/blog.txt     |  2 ++
 challenge-211/wlmb/perl/ch-1.pl | 24 ++++++++++++++++++++++++
 challenge-211/wlmb/perl/ch-2.pl | 22 ++++++++++++++++++++++
 3 files changed, 48 insertions(+)
 create mode 100644 challenge-211/wlmb/blog.txt
 create mode 100755 challenge-211/wlmb/perl/ch-1.pl
 create mode 100755 challenge-211/wlmb/perl/ch-2.pl

(limited to 'challenge-211')

diff --git a/challenge-211/wlmb/blog.txt b/challenge-211/wlmb/blog.txt
new file mode 100644
index 0000000000..5d17477df3
--- /dev/null
+++ b/challenge-211/wlmb/blog.txt
@@ -0,0 +1,2 @@
+https://wlmb.github.io/2023/04/03/PWC211/
+
diff --git a/challenge-211/wlmb/perl/ch-1.pl b/challenge-211/wlmb/perl/ch-1.pl
new file mode 100755
index 0000000000..0e2873fda2
--- /dev/null
+++ b/challenge-211/wlmb/perl/ch-1.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/env perl
+# Perl weekly challenge 211
+# Task 1:  Toeplitz Matrix
+#
+# See https://wlmb.github.io/2023/04/03/PWC211/#task-1-toeplitz-matrix
+use v5.36;
+use List::Util qw(max min uniq);
+my @matrix;
+my $N=0; # number of rows
+while(<>){ # read the matrix, a space separated row at a time
+    $matrix[$N++]=[split " "];
+}
+my $M=@{$matrix[0]}; # Number of columns
+@{$matrix[$_]}==$M || die "Not rectangular"  for(1..$N-1);
+my $largest=max($N,$M);
+my $toeplitz=1;      # matrix is toeplitz
+for my $diagonal(-$M+1..$N-1){
+    $toeplitz &&=    # unless it is not
+        1==uniq
+	map {$matrix[$diagonal+$_][$_]}
+        max(0, -$diagonal)..min($M-1,$N-$diagonal-1);
+}
+say "@{$matrix[$_]}" for 0..$N-1;
+say " -> ", $toeplitz?"true":"false";
diff --git a/challenge-211/wlmb/perl/ch-2.pl b/challenge-211/wlmb/perl/ch-2.pl
new file mode 100755
index 0000000000..ae25ceea91
--- /dev/null
+++ b/challenge-211/wlmb/perl/ch-2.pl
@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+# Perl weekly challenge 211
+# Task 2:  Split Same Average
+#
+# See https://wlmb.github.io/2023/04/03/PWC211/#task-2-split-same-average
+use v5.36;
+use Algorithm::Combinatorics qw(subsets);
+use List::Util qw(sum);
+die <<~"FIN" unless @ARGV;
+    Usage: $0 N1 [N2...]
+    to test if the set N1 N2... may be split into two proper subsets
+    with the same average
+    FIN
+my $avg=sum(@ARGV)/@ARGV;
+my $subsets=subsets(\@ARGV);
+$subsets->next; # Throw away the complete set
+my $candidate;
+while($candidate=$subsets->next){
+    next if @$candidate==0;  # Throw away the empty set
+    last if sum(@$candidate)==$avg*@$candidate; # success
+}
+say("@ARGV -> ", $candidate && @$candidate? "True: @$candidate" : "False")
-- 
cgit 


From 8ab37815f55b019f73272256613e2e432fa0da7c Mon Sep 17 00:00:00 2001
From: robbie-hatley <Robbie.Hatley@gmail.com>
Date: Mon, 3 Apr 2023 21:05:13 -0700
Subject: Robbie Hatley's Perl solutions to The Weekly Challenge 211

---
 challenge-211/robbie-hatley/blog.txt |   1 +
 challenge-211/robbie-hatley/ch-1.pl  |  90 ++++++++++++++++++++++++++
 challenge-211/robbie-hatley/ch-2.pl  | 118 +++++++++++++++++++++++++++++++++++
 3 files changed, 209 insertions(+)
 create mode 100644 challenge-211/robbie-hatley/blog.txt
 create mode 100755 challenge-211/robbie-hatley/ch-1.pl
 create mode 100755 challenge-211/robbie-hatley/ch-2.pl

(limited to 'challenge-211')

diff --git a/challenge-211/robbie-hatley/blog.txt b/challenge-211/robbie-hatley/blog.txt
new file mode 100644
index 0000000000..03447b9b02
--- /dev/null
+++ b/challenge-211/robbie-hatley/blog.txt
@@ -0,0 +1 @@
+https://hatley-software.blogspot.com/2023/04/robbie-hatleys-perl-solutions-to-weekly.html
\ No newline at end of file
diff --git a/challenge-211/robbie-hatley/ch-1.pl b/challenge-211/robbie-hatley/ch-1.pl
new file mode 100755
index 0000000000..be58407553
--- /dev/null
+++ b/challenge-211/robbie-hatley/ch-1.pl
@@ -0,0 +1,90 @@
+#! /bin/perl
+# Robbie Hatley's Perl solutions to The Weekly Challenge #211-1
+
+# ======================================================================
+# PROBLEM DESCRIPTION:
+
+=pod
+
+Task 1: Toeplitz Matrix
+Submitted by: Mohammad S Anwar
+You are given a matrix m x n. Write a script to find out if the given 
+matrix is Toeplitz Matrix. A matrix is Toeplitz if every diagonal from 
+top-left to bottom-right has the same elements.
+
+Example 1:
+Input:  [[4, 3, 2, 1], [5, 4, 3, 2], [6, 5, 4, 3]]
+Output: true
+
+Example 2:
+Input:  [[1, 2, 3], [3, 2, 1]]
+Output: false
+
+=cut
+
+# ======================================================================
+# INPUT / OUTPUT NOTES:
+# Input is from built-in array-of-arrays or from @ARGV. If using @ARGV,
+# input should be one 'single-quoted' string expressing an array of 
+# arrays of arrays of integers in valid Perl syntax, with each array
+# containing only arrays of the same size, like so:
+# ./ch-1.pl '([[1,2],[2,3]], [[1,3,5],[3,5,1],[5,1,3]])'
+#
+# Output is to STDOUT and will be the input array followed by
+# "Matrix IS Toeplitz" or "Matrix is NOT Toeplitz"
+
+# ======================================================================
+# PRELIMINARIES:
+use v5.36;
+use strict;
+use warnings;
+
+# ======================================================================
+# SUBROUTINES:
+
+# Say whether-or-not a referred-to rectangular 2-d matrix is Toeplitz,
+# without altering the original matrix:
+sub is_toeplitz($mref){
+   # Make a deep copy of @$aref (simple copy is NOT deep copy!!!):
+   my $height = scalar(@$mref);
+   my $width  = scalar(@{$mref->[0]});
+   say "Height = $height";
+   say "Width  = $width";
+   # Test length 2+ diagonals starting from top:
+   for ( my $i = 0 ; $i <= $width-2 ; ++$i ){
+      for ( my $j = $i+1, my $k = 1 ; $j < $width && $k < $height ; ++$j, ++$k ){
+         return 0 if $mref->[$k]->[$j] != $mref->[0]->[$i];
+      }
+   }
+   # Test length 2+ diagonals starting from left:
+   for ( my $i = 1 ; $i <= $height-2 ; ++$i ){
+      for ( my $j = 1, my $k = $i+1 ; $j < $width && $k < $height ; ++$j, ++$k ){
+         return 0 if $mref->[$k]->[$j] != $mref->[$i]->[0];
+      }
+   }
+   return 1;
+}
+
+# ======================================================================
+# DEFAULT INPUTS:
+my @matrices = 
+(
+   [[4, 3, 2, 1], [5, 4, 3, 2], [6, 5, 4, 3]],
+   [[1, 2, 3], [3, 2, 1]],
+   [[1,2],[2,1]],
+   [[1,3,5],[3,5,1],[5,1,3]],
+   [[1,5],[4,1],[2,4]],
+);
+
+# ======================================================================
+# NON-DEFAULT INPUTS:
+if (@ARGV) {@matrices = eval($ARGV[0])}
+
+# ======================================================================
+# MAIN BODY OF SCRIPT:
+for my $matrix (@matrices){
+   say '';
+   say 'Matrix:';
+   say "@$_" for @$matrix;
+   say is_toeplitz($matrix) ? "Matrix IS Toeplitz" : "Matrix is NOT Toeplitz";
+}
diff --git a/challenge-211/robbie-hatley/ch-2.pl b/challenge-211/robbie-hatley/ch-2.pl
new file mode 100755
index 0000000000..13325d3912
--- /dev/null
+++ b/challenge-211/robbie-hatley/ch-2.pl
@@ -0,0 +1,118 @@
+#! /bin/perl
+# Robbie Hatley's Perl solutions to The Weekly Challenge #211-2
+
+# ======================================================================
+# PROBLEM DESCRIPTION:
+
+=pod
+
+Task 2: Split Same Average
+Submitted by: Mohammad S Anwar
+You are given an array of integers. Write a script to find out if the 
+given can be split into two separate arrays whose average are the same.
+
+Example 1:  Input=(1, 2, 3, 4, 5, 6, 7, 8)  Output=true
+Example 2:  Input=(1, 3)                    Output=false
+
+=cut
+
+# ======================================================================
+# INPUT / OUTPUT NOTES:
+# Input is from built-in array-of-arrays or from @ARGV. If using @ARGV,
+# input should be one 'single-quoted' string expressing an array of 
+# arrays of integers in valid Perl syntax.
+#
+# Output is to STDOUT and will be input array followed by either 
+# a split with equal averages or a notice that no such split exists.
+
+# ======================================================================
+# PRELIMINARIES:
+use v5.36;
+use strict;
+use warnings;
+use Set::Partition;
+use List::AllUtils 'sum0';
+$"=', ';
+
+# ======================================================================
+# VARIABLES:
+my $db = 0; # Debug?
+
+# ======================================================================
+# SUBROUTINES:
+
+# Obtain an array of all partitions of a given set into two non-empty
+# parts with the size of the first part not-greater-than the size of the
+# second part (to avoid duplicate partitions):
+sub two_non_empty ($aref, $partref){
+   # How big is the original array?
+   my $size  = scalar(@{$aref});
+   # No need to allow the first part to be more than half the size
+   # of the array, else we'd get duplicate partitions:
+   my $limit = int($size/2);
+   for ( my $n = 1 ; $n <= $limit ; ++$n ){
+      my $parts = Set::Partition->new(
+         list      => $aref,
+         partition => [$n, $size - $n],
+      );
+      while (my $part = $parts->next) {
+         push @{$partref}, $part;
+      }
+   }
+}
+
+# What is the average of the real numbers in a referred-to array?
+sub average ($aref) {return sum0(@$aref)/scalar(@$aref);}
+
+# Are two floating-point numbers "equal" to within one millionth?
+sub equal ($x, $y) {abs($x-$y) < 0.000001 ? return 1 : return 0;}
+
+# ======================================================================
+# DEFAULT INPUTS:
+my @arrays = 
+(
+   [1, 2, 3, 4, 5, 6, 7, 8],
+   [1, 3],
+   [3, 6, -2.3, 8.64, 5.36],
+   [3, 6, -2, 8, 5],
+   [4, 6, 8, 9]
+);
+
+# ======================================================================
+# NON-DEFAULT INPUTS:
+if (@ARGV) {@arrays = eval($ARGV[0])}
+
+# ======================================================================
+# MAIN BODY OF SCRIPT:
+
+ARRAY: for (@arrays){
+   say '';
+   say "array = (@$_)";
+   my $partitions = [];
+   two_non_empty($_, $partitions);
+   my $equal_average_flag = 0;
+   # If debugging, print lots of extra diagnostics:
+   if ($db) {
+      say 'Partitions:';
+      for (@$partitions){
+         my $a1 = average($_->[0]);
+         my $a2 = average($_->[1]);
+         my $e = equal($a1, $a2) ? 'EQUAL!!!' : '';
+         say("(@{$_->[0]}) (@{$_->[1]}) $a1 $a2 $e");
+      }
+   }
+   # Otherwise, just print the basics:
+   else {
+      for (@$partitions){
+         my $a1 = average($_->[0]);
+         my $a2 = average($_->[1]);
+         if (equal($a1, $a2)) {
+            say 'array can be split into '
+              . "(@{$_->[0]}) and (@{$_->[1]}), "
+              . "both with average $a1";
+            next ARRAY;
+         }
+      }
+      say 'No equal-average split exists.';
+   }
+}
-- 
cgit 


From 21d3311f8353c8423f56bab95e4910190d8633f3 Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Tue, 4 Apr 2023 05:35:00 +0000
Subject: Challenge 211 Solutions (Raku)

---
 challenge-211/mark-anderson/raku/ch-1.raku |  2 +-
 challenge-211/mark-anderson/raku/ch-2.raku | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

(limited to 'challenge-211')

diff --git a/challenge-211/mark-anderson/raku/ch-1.raku b/challenge-211/mark-anderson/raku/ch-1.raku
index 2b86bde846..4519f643b6 100644
--- a/challenge-211/mark-anderson/raku/ch-1.raku
+++ b/challenge-211/mark-anderson/raku/ch-1.raku
@@ -21,5 +21,5 @@ ok  toeplitz([1,2],
 
 sub toeplitz(+@m)
 {
-    @m[^@m.end;^@m[0].end] eqv @m[1..@m.end;1..@m[1].end]
+    @m[ ^@m.end; ^@m[0].end ] eqv @m[ 1..@m.end; 1..@m[1].end ]
 }
diff --git a/challenge-211/mark-anderson/raku/ch-2.raku b/challenge-211/mark-anderson/raku/ch-2.raku
index b6563db667..255ada41f4 100644
--- a/challenge-211/mark-anderson/raku/ch-2.raku
+++ b/challenge-211/mark-anderson/raku/ch-2.raku
@@ -1,21 +1,21 @@
 #!/usr/bin/env raku
 use Test;
 
-ok  split-same-avg(1,2,3,4,5,6,7,8); # [1 8] [5 4 6 3 7 2]
+ok  split-same-avg(1,2,3,4,5,6,7,8); # [1 8] [2 3 4 5 6 7]
 nok split-same-avg(1,3);
-ok  split-same-avg(3,3,5,5,5,2,2,1); # [3 3 5 2] [2 5 5 1]
+ok  split-same-avg(3,3,5,5,5,2,2,1); # [2 3 3 5] [1 2 5 5]
 nok split-same-avg(5,5,5,2,2,1); 
 
 sub split-same-avg(*@nums)
 {
-    for (^@nums).combinations(1..(@nums.elems div 2)) -> @a is copy
+    for (^@nums).combinations(1..@nums.elems div 2) -> @a is copy
     {
-        my @b = ((^@nums) (-) @a).keys;
+        my @b = (^@nums (-) @a).keys;
 
         @a = @nums[@a];
         @b = @nums[@b];
 
-        return True if (@a.sum / @a.elems) == (@b.sum / @b.elems)
+        return True if @a.sum / @a.elems == @b.sum / @b.elems
     }
 
     return False
-- 
cgit 


From a3d0f8555cad823c79011a4a0fecd71c4d17f063 Mon Sep 17 00:00:00 2001
From: robbie-hatley <Robbie.Hatley@gmail.com>
Date: Wed, 5 Apr 2023 06:25:31 -0700
Subject: fixed some errors

---
 challenge-211/robbie-hatley/ch-1.pl      |  90 -----------------------
 challenge-211/robbie-hatley/ch-2.pl      | 118 -------------------------------
 challenge-211/robbie-hatley/perl/ch-1.pl |  89 +++++++++++++++++++++++
 challenge-211/robbie-hatley/perl/ch-2.pl | 118 +++++++++++++++++++++++++++++++
 4 files changed, 207 insertions(+), 208 deletions(-)
 delete mode 100755 challenge-211/robbie-hatley/ch-1.pl
 delete mode 100755 challenge-211/robbie-hatley/ch-2.pl
 create mode 100755 challenge-211/robbie-hatley/perl/ch-1.pl
 create mode 100755 challenge-211/robbie-hatley/perl/ch-2.pl

(limited to 'challenge-211')

diff --git a/challenge-211/robbie-hatley/ch-1.pl b/challenge-211/robbie-hatley/ch-1.pl
deleted file mode 100755
index be58407553..0000000000
--- a/challenge-211/robbie-hatley/ch-1.pl
+++ /dev/null
@@ -1,90 +0,0 @@
-#! /bin/perl
-# Robbie Hatley's Perl solutions to The Weekly Challenge #211-1
-
-# ======================================================================
-# PROBLEM DESCRIPTION:
-
-=pod
-
-Task 1: Toeplitz Matrix
-Submitted by: Mohammad S Anwar
-You are given a matrix m x n. Write a script to find out if the given 
-matrix is Toeplitz Matrix. A matrix is Toeplitz if every diagonal from 
-top-left to bottom-right has the same elements.
-
-Example 1:
-Input:  [[4, 3, 2, 1], [5, 4, 3, 2], [6, 5, 4, 3]]
-Output: true
-
-Example 2:
-Input:  [[1, 2, 3], [3, 2, 1]]
-Output: false
-
-=cut
-
-# ======================================================================
-# INPUT / OUTPUT NOTES:
-# Input is from built-in array-of-arrays or from @ARGV. If using @ARGV,
-# input should be one 'single-quoted' string expressing an array of 
-# arrays of arrays of integers in valid Perl syntax, with each array
-# containing only arrays of the same size, like so:
-# ./ch-1.pl '([[1,2],[2,3]], [[1,3,5],[3,5,1],[5,1,3]])'
-#
-# Output is to STDOUT and will be the input array followed by
-# "Matrix IS Toeplitz" or "Matrix is NOT Toeplitz"
-
-# ======================================================================
-# PRELIMINARIES:
-use v5.36;
-use strict;
-use warnings;
-
-# ======================================================================
-# SUBROUTINES:
-
-# Say whether-or-not a referred-to rectangular 2-d matrix is Toeplitz,
-# without altering the original matrix:
-sub is_toeplitz($mref){
-   # Make a deep copy of @$aref (simple copy is NOT deep copy!!!):
-   my $height = scalar(@$mref);
-   my $width  = scalar(@{$mref->[0]});
-   say "Height = $height";
-   say "Width  = $width";
-   # Test length 2+ diagonals starting from top:
-   for ( my $i = 0 ; $i <= $width-2 ; ++$i ){
-      for ( my $j = $i+1, my $k = 1 ; $j < $width && $k < $height ; ++$j, ++$k ){
-         return 0 if $mref->[$k]->[$j] != $mref->[0]->[$i];
-      }
-   }
-   # Test length 2+ diagonals starting from left:
-   for ( my $i = 1 ; $i <= $height-2 ; ++$i ){
-      for ( my $j = 1, my $k = $i+1 ; $j < $width && $k < $height ; ++$j, ++$k ){
-         return 0 if $mref->[$k]->[$j] != $mref->[$i]->[0];
-      }
-   }
-   return 1;
-}
-
-# ======================================================================
-# DEFAULT INPUTS:
-my @matrices = 
-(
-   [[4, 3, 2, 1], [5, 4, 3, 2], [6, 5, 4, 3]],
-   [[1, 2, 3], [3, 2, 1]],
-   [[1,2],[2,1]],
-   [[1,3,5],[3,5,1],[5,1,3]],
-   [[1,5],[4,1],[2,4]],
-);
-
-# ======================================================================
-# NON-DEFAULT INPUTS:
-if (@ARGV) {@matrices = eval($ARGV[0])}
-
-# ======================================================================
-# MAIN BODY OF SCRIPT:
-for my $matrix (@matrices){
-   say '';
-   say 'Matrix:';
-   say "@$_" for @$matrix;
-   say is_toeplitz($matrix) ? "Matrix IS Toeplitz" : "Matrix is NOT Toeplitz";
-}
diff --git a/challenge-211/robbie-hatley/ch-2.pl b/challenge-211/robbie-hatley/ch-2.pl
deleted file mode 100755
index 13325d3912..0000000000
--- a/challenge-211/robbie-hatley/ch-2.pl
+++ /dev/null
@@ -1,118 +0,0 @@
-#! /bin/perl
-# Robbie Hatley's Perl solutions to The Weekly Challenge #211-2
-
-# ======================================================================
-# PROBLEM DESCRIPTION:
-
-=pod
-
-Task 2: Split Same Average
-Submitted by: Mohammad S Anwar
-You are given an array of integers. Write a script to find out if the 
-given can be split into two separate arrays whose average are the same.
-
-Example 1:  Input=(1, 2, 3, 4, 5, 6, 7, 8)  Output=true
-Example 2:  Input=(1, 3)                    Output=false
-
-=cut
-
-# ======================================================================
-# INPUT / OUTPUT NOTES:
-# Input is from built-in array-of-arrays or from @ARGV. If using @ARGV,
-# input should be one 'single-quoted' string expressing an array of 
-# arrays of integers in valid Perl syntax.
-#
-# Output is to STDOUT and will be input array followed by either 
-# a split with equal averages or a notice that no such split exists.
-
-# ======================================================================
-# PRELIMINARIES:
-use v5.36;
-use strict;
-use warnings;
-use Set::Partition;
-use List::AllUtils 'sum0';
-$"=', ';
-
-# ======================================================================
-# VARIABLES:
-my $db = 0; # Debug?
-
-# ======================================================================
-# SUBROUTINES:
-
-# Obtain an array of all partitions of a given set into two non-empty
-# parts with the size of the first part not-greater-than the size of the
-# second part (to avoid duplicate partitions):
-sub two_non_empty ($aref, $partref){
-   # How big is the original array?
-   my $size  = scalar(@{$aref});
-   # No need to allow the first part to be more than half the size
-   # of the array, else we'd get duplicate partitions:
-   my $limit = int($size/2);
-   for ( my $n = 1 ; $n <= $limit ; ++$n ){
-      my $parts = Set::Partition->new(
-         list      => $aref,
-         partition => [$n, $size - $n],
-      );
-      while (my $part = $parts->next) {
-         push @{$partref}, $part;
-      }
-   }
-}
-
-# What is the average of the real numbers in a referred-to array?
-sub average ($aref) {return sum0(@$aref)/scalar(@$aref);}
-
-# Are two floating-point numbers "equal" to within one millionth?
-sub equal ($x, $y) {abs($x-$y) < 0.000001 ? return 1 : return 0;}
-
-# ======================================================================
-# DEFAULT INPUTS:
-my @arrays = 
-(
-   [1, 2, 3, 4, 5, 6, 7, 8],
-   [1, 3],
-   [3, 6, -2.3, 8.64, 5.36],
-   [3, 6, -2, 8, 5],
-   [4, 6, 8, 9]
-);
-
-# ======================================================================
-# NON-DEFAULT INPUTS:
-if (@ARGV) {@arrays = eval($ARGV[0])}
-
-# ======================================================================
-# MAIN BODY OF SCRIPT:
-
-ARRAY: for (@arrays){
-   say '';
-   say "array = (@$_)";
-   my $partitions = [];
-   two_non_empty($_, $partitions);
-   my $equal_average_flag = 0;
-   # If debugging, print lots of extra diagnostics:
-   if ($db) {
-      say 'Partitions:';
-      for (@$partitions){
-         my $a1 = average($_->[0]);
-         my $a2 = average($_->[1]);
-         my $e = equal($a1, $a2) ? 'EQUAL!!!' : '';
-         say("(@{$_->[0]}) (@{$_->[1]}) $a1 $a2 $e");
-      }
-   }
-   # Otherwise, just print the basics:
-   else {
-      for (@$partitions){
-         my $a1 = average($_->[0]);
-         my $a2 = average($_->[1]);
-         if (equal($a1, $a2)) {
-            say 'array can be split into '
-              . "(@{$_->[0]}) and (@{$_->[1]}), "
-              . "both with average $a1";
-            next ARRAY;
-         }
-      }
-      say 'No equal-average split exists.';
-   }
-}
diff --git a/challenge-211/robbie-hatley/perl/ch-1.pl b/challenge-211/robbie-hatley/perl/ch-1.pl
new file mode 100755
index 0000000000..3fffd3cd1a
--- /dev/null
+++ b/challenge-211/robbie-hatley/perl/ch-1.pl
@@ -0,0 +1,89 @@
+#! /bin/perl
+# Robbie Hatley's Perl solutions to The Weekly Challenge #211-1
+
+# ======================================================================
+# PROBLEM DESCRIPTION:
+
+=pod
+
+Task 1: Toeplitz Matrix
+Submitted by: Mohammad S Anwar
+You are given a matrix m x n. Write a script to find out if the given 
+matrix is Toeplitz Matrix. A matrix is Toeplitz if every diagonal from 
+top-left to bottom-right has the same elements.
+
+Example 1:
+Input:  [[4, 3, 2, 1], [5, 4, 3, 2], [6, 5, 4, 3]]
+Output: true
+
+Example 2:
+Input:  [[1, 2, 3], [3, 2, 1]]
+Output: false
+
+=cut
+
+# ======================================================================
+# INPUT / OUTPUT NOTES:
+# Input is from built-in array-of-arrays or from @ARGV. If using @ARGV,
+# input should be one 'single-quoted' string expressing an array of 
+# arrays of arrays of integers in valid Perl syntax, with each array
+# containing only arrays of the same size, like so:
+# ./ch-1.pl '([[1,2],[2,3]], [[1,3,5],[3,5,1],[5,1,3]])'
+#
+# Output is to STDOUT and will be the input array followed by
+# "Matrix IS Toeplitz" or "Matrix is NOT Toeplitz"
+
+# ======================================================================
+# PRELIMINARIES:
+use v5.36;
+use strict;
+use warnings;
+
+# ======================================================================
+# SUBROUTINES:
+
+# Say whether-or-not a referred-to rectangular 2-d matrix is Toeplitz,
+# without altering the original matrix:
+sub is_toeplitz($mref){
+   my $height = scalar(@$mref);
+   my $width  = scalar(@{$mref->[0]});
+   say "Height = $height";
+   say "Width  = $width";
+   # Test length 2+ diagonals starting from top:
+   for ( my $i = 0 ; $i <= $width-2 ; ++$i ){
+      for ( my $j = $i+1, my $k = 1 ; $j < $width && $k < $height ; ++$j, ++$k ){
+         return 0 if $mref->[$k]->[$j] != $mref->[0]->[$i];
+      }
+   }
+   # Test length 2+ diagonals starting from left:
+   for ( my $i = 1 ; $i <= $height-2 ; ++$i ){
+      for ( my $j = 1, my $k = $i+1 ; $j < $width && $k < $height ; ++$j, ++$k ){
+         return 0 if $mref->[$k]->[$j] != $mref->[$i]->[0];
+      }
+   }
+   return 1;
+}
+
+# ======================================================================
+# DEFAULT INPUTS:
+my @matrices = 
+(
+   [[4, 3, 2, 1], [5, 4, 3, 2], [6, 5, 4, 3]],
+   [[1, 2, 3], [3, 2, 1]],
+   [[1,2],[2,1]],
+   [[1,3,5],[3,5,1],[5,1,3]],
+   [[1,5],[4,1],[2,4]],
+);
+
+# ======================================================================
+# NON-DEFAULT INPUTS:
+if (@ARGV) {@matrices = eval($ARGV[0])}
+
+# ======================================================================
+# MAIN BODY OF SCRIPT:
+for my $matrix (@matrices){
+   say '';
+   say 'Matrix:';
+   say "@$_" for @$matrix;
+   say is_toeplitz($matrix) ? "Matrix IS Toeplitz" : "Matrix is NOT Toeplitz";
+}
diff --git a/challenge-211/robbie-hatley/perl/ch-2.pl b/challenge-211/robbie-hatley/perl/ch-2.pl
new file mode 100755
index 0000000000..13325d3912
--- /dev/null
+++ b/challenge-211/robbie-hatley/perl/ch-2.pl
@@ -0,0 +1,118 @@
+#! /bin/perl
+# Robbie Hatley's Perl solutions to The Weekly Challenge #211-2
+
+# ======================================================================
+# PROBLEM DESCRIPTION:
+
+=pod
+
+Task 2: Split Same Average
+Submitted by: Mohammad S Anwar
+You are given an array of integers. Write a script to find out if the 
+given can be split into two separate arrays whose average are the same.
+
+Example 1:  Input=(1, 2, 3, 4, 5, 6, 7, 8)  Output=true
+Example 2:  Input=(1, 3)                    Output=false
+
+=cut
+
+# ======================================================================
+# INPUT / OUTPUT NOTES:
+# Input is from built-in array-of-arrays or from @ARGV. If using @ARGV,
+# input should be one 'single-quoted' string expressing an array of 
+# arrays of integers in valid Perl syntax.
+#
+# Output is to STDOUT and will be input array followed by either 
+# a split with equal averages or a notice that no such split exists.
+
+# ======================================================================
+# PRELIMINARIES:
+use v5.36;
+use strict;
+use warnings;
+use Set::Partition;
+use List::AllUtils 'sum0';
+$"=', ';
+
+# ======================================================================
+# VARIABLES:
+my $db = 0; # Debug?
+
+# ======================================================================
+# SUBROUTINES:
+
+# Obtain an array of all partitions of a given set into two non-empty
+# parts with the size of the first part not-greater-than the size of the
+# second part (to avoid duplicate partitions):
+sub two_non_empty ($aref, $partref){
+   # How big is the original array?
+   my $size  = scalar(@{$aref});
+   # No need to allow the first part to be more than half the size
+   # of the array, else we'd get duplicate partitions:
+   my $limit = int($size/2);
+   for ( my $n = 1 ; $n <= $limit ; ++$n ){
+      my $parts = Set::Partition->new(
+         list      => $aref,
+         partition => [$n, $size - $n],
+      );
+      while (my $part = $parts->next) {
+         push @{$partref}, $part;
+      }
+   }
+}
+
+# What is the average of the real numbers in a referred-to array?
+sub average ($aref) {return sum0(@$aref)/scalar(@$aref);}
+
+# Are two floating-point numbers "equal" to within one millionth?
+sub equal ($x, $y) {abs($x-$y) < 0.000001 ? return 1 : return 0;}
+
+# ======================================================================
+# DEFAULT INPUTS:
+my @arrays = 
+(
+   [1, 2, 3, 4, 5, 6, 7, 8],
+   [1, 3],
+   [3, 6, -2.3, 8.64, 5.36],
+   [3, 6, -2, 8, 5],
+   [4, 6, 8, 9]
+);
+
+# ======================================================================
+# NON-DEFAULT INPUTS:
+if (@ARGV) {@arrays = eval($ARGV[0])}
+
+# ======================================================================
+# MAIN BODY OF SCRIPT:
+
+ARRAY: for (@arrays){
+   say '';
+   say "array = (@$_)";
+   my $partitions = [];
+   two_non_empty($_, $partitions);
+   my $equal_average_flag = 0;
+   # If debugging, print lots of extra diagnostics:
+   if ($db) {
+      say 'Partitions:';
+      for (@$partitions){
+         my $a1 = average($_->[0]);
+         my $a2 = average($_->[1]);
+         my $e = equal($a1, $a2) ? 'EQUAL!!!' : '';
+         say("(@{$_->[0]}) (@{$_->[1]}) $a1 $a2 $e");
+      }
+   }
+   # Otherwise, just print the basics:
+   else {
+      for (@$partitions){
+         my $a1 = average($_->[0]);
+         my $a2 = average($_->[1]);
+         if (equal($a1, $a2)) {
+            say 'array can be split into '
+              . "(@{$_->[0]}) and (@{$_->[1]}), "
+              . "both with average $a1";
+            next ARRAY;
+         }
+      }
+      say 'No equal-average split exists.';
+   }
+}
-- 
cgit 


From d1a80636474c530b07c08886a8a6b896c9421418 Mon Sep 17 00:00:00 2001
From: robbie-hatley <Robbie.Hatley@gmail.com>
Date: Wed, 5 Apr 2023 06:44:14 -0700
Subject: made some improvements

---
 challenge-211/robbie-hatley/perl/ch-2.pl | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

(limited to 'challenge-211')

diff --git a/challenge-211/robbie-hatley/perl/ch-2.pl b/challenge-211/robbie-hatley/perl/ch-2.pl
index 13325d3912..6daeb97d97 100755
--- a/challenge-211/robbie-hatley/perl/ch-2.pl
+++ b/challenge-211/robbie-hatley/perl/ch-2.pl
@@ -44,21 +44,24 @@ my $db = 0; # Debug?
 # Obtain an array of all partitions of a given set into two non-empty
 # parts with the size of the first part not-greater-than the size of the
 # second part (to avoid duplicate partitions):
-sub two_non_empty ($aref, $partref){
+sub two_non_empty ($aref){
    # How big is the original array?
    my $size  = scalar(@{$aref});
+   # Make an array to hold partitions:
+   my @partitions;
    # No need to allow the first part to be more than half the size
    # of the array, else we'd get duplicate partitions:
    my $limit = int($size/2);
    for ( my $n = 1 ; $n <= $limit ; ++$n ){
-      my $parts = Set::Partition->new(
+      my $size_n_partitions = Set::Partition->new(
          list      => $aref,
          partition => [$n, $size - $n],
       );
-      while (my $part = $parts->next) {
-         push @{$partref}, $part;
+      while (my $partition = $size_n_partitions->next) {
+         push @partitions, $partition;
       }
    }
+   return \@partitions;
 }
 
 # What is the average of the real numbers in a referred-to array?
@@ -88,8 +91,7 @@ if (@ARGV) {@arrays = eval($ARGV[0])}
 ARRAY: for (@arrays){
    say '';
    say "array = (@$_)";
-   my $partitions = [];
-   two_non_empty($_, $partitions);
+   my $partitions = two_non_empty($_);
    my $equal_average_flag = 0;
    # If debugging, print lots of extra diagnostics:
    if ($db) {
-- 
cgit 


From 6e98239f9d7df539606d6f6412d9aae8002851ae Mon Sep 17 00:00:00 2001
From: Jörg Sommrey <28217714+jo-37@users.noreply.github.com>
Date: Mon, 3 Apr 2023 23:06:58 +0200
Subject: Solution to task 1

---
 challenge-211/jo-37/perl/ch-1.pl | 85 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100755 challenge-211/jo-37/perl/ch-1.pl

(limited to 'challenge-211')

diff --git a/challenge-211/jo-37/perl/ch-1.pl b/challenge-211/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..586b91905e
--- /dev/null
+++ b/challenge-211/jo-37/perl/ch-1.pl
@@ -0,0 +1,85 @@
+#!/usr/bin/perl -s
+
+use v5.16;
+use Test2::V0 '!float';
+use PDL;
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV;
+usage: $0 [-examples] [-tests] [Matrix]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+Matrix
+    a string representation of a matrix as accepted by the PDL constructor,
+    e.g. "[3 2 1] [4 3 2]"
+
+EOS
+
+
+### Input and Output
+
+say is_toeplitz("@ARGV") ? 'true' : 'false';
+
+
+### Implementation
+
+# A NxM matrix (N,M > 1) has N + M - 3 diagonals having more than one
+# element.  Creating a set of NxN matrices where each of them have one
+# of the orignal matrix' diagonals as its main diagonal.  Then take the
+# diagonal of these matrices and re-arrange them into a new matrix
+# having the main diagonals of the matrix series as rows. Taking minimum
+# and maximum over the rows.  If min and max equals for every row, the
+# matrix is Toeplitz.
+# Note: Utilizing BAD values in incomplete diagonals that do not account
+# for minimum or maximum.
+sub is_toeplitz {
+	(my $m = pdl @_)->badflag(1);
+    my ($min, $max) = (
+        cat map $_->diagonal(0, 1),
+        $m->range($m->dim(0) - 2 - sequence(indx, 1, $m->shape->sum - 3),
+            $m->dim(1), 't')
+        ->reorder(1,2,0)->dog
+    )->minmaximum;
+
+    all $min == $max;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+        
+        ok is_toeplitz(
+            [4, 3, 2, 1],
+            [5, 4, 3, 2],
+            [6, 5, 4, 3]), 'example 1';
+
+        ok !is_toeplitz(
+            [1, 2, 3],
+            [3, 2, 1]), 'example 2';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        ok is_toeplitz(sequence(4) + 5 - sequence(5)->dummy(0)), '4 x 5';
+        ok is_toeplitz(sequence(5) + 4 - sequence(4)->dummy(0)), '5 x 4';
+
+        my $nt = sequence(4) + 5 - sequence(5)->dummy(0);
+        $nt->set(1, 4, 0);
+        ok !is_toeplitz($nt), 'one element failing';
+	}
+
+    done_testing;
+    exit;
+}
-- 
cgit 


From 2bcb7ffce5bfbf0c9f1e23ef714c678f9f992a8a Mon Sep 17 00:00:00 2001
From: Jörg Sommrey <28217714+jo-37@users.noreply.github.com>
Date: Tue, 4 Apr 2023 22:31:34 +0200
Subject: Solution to task 2

---
 challenge-211/jo-37/perl/ch-2.pl | 73 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100755 challenge-211/jo-37/perl/ch-2.pl

(limited to 'challenge-211')

diff --git a/challenge-211/jo-37/perl/ch-2.pl b/challenge-211/jo-37/perl/ch-2.pl
new file mode 100755
index 0000000000..dd2c6b03fb
--- /dev/null
+++ b/challenge-211/jo-37/perl/ch-2.pl
@@ -0,0 +1,73 @@
+#!/usr/bin/perl -s
+
+use v5.16;
+use Test2::V0;
+use Math::Prime::Util qw(forcomb lastfor);
+use List::Util qw(sum);
+use experimental qw(signatures);
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV;
+usage: $0 [-examples] [-tests] [--] [N...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+N...
+    list of numbers
+
+EOS
+
+
+### Input and Output
+
+say same_average(@ARGV) ? 'true' : 'false';
+
+
+### Implementation
+
+# It can easily be shown that if two partitions of the list have the
+# same average, this common average equals the average of the whole
+# list.  Thus all we need to do is find a nonempty true subset of the
+# list having the same average as the list.  The complement will have
+# the same average.
+
+sub same_average (@list) {
+    state $delta = 1e-6;
+    my $avg = sum(@list) / @list;
+    my $res;
+    # Loop over all subsets.
+    forcomb {
+        # Skip non true subsets.
+        return unless @_ && @_ != @list;
+        $res = 1, lastfor if abs($avg - sum(@list[@_]) / @_) < $delta;
+    } @list;
+
+    $res;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        ok same_average(1, 2, 3, 4, 5, 6, 7, 8), 'example 1';
+        ok !same_average(1, 3), 'example 2';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+        ok same_average(1, 1, 1, 1, 5, 9,), '(1 5), (1 1 1 9)';
+	}
+
+    done_testing;
+    exit;
+}
-- 
cgit 


From 22437e2fa18fda4713254cc11efdc21f4ece082a Mon Sep 17 00:00:00 2001
From: Roger Bell_West <roger@firedrake.org>
Date: Thu, 6 Apr 2023 11:36:26 +0100
Subject: RogerBW solutions for challenge no. 211

---
 challenge-211/roger-bell-west/javascript/ch-1.js |  44 +++++++++
 challenge-211/roger-bell-west/javascript/ch-2.js |  69 ++++++++++++++
 challenge-211/roger-bell-west/kotlin/ch-1.kt     |  44 +++++++++
 challenge-211/roger-bell-west/kotlin/ch-2.kt     |  69 ++++++++++++++
 challenge-211/roger-bell-west/lua/ch-1.lua       |  46 +++++++++
 challenge-211/roger-bell-west/lua/ch-2.lua       |  78 ++++++++++++++++
 challenge-211/roger-bell-west/perl/ch-1.pl       |  38 ++++++++
 challenge-211/roger-bell-west/perl/ch-2.pl       |  35 +++++++
 challenge-211/roger-bell-west/postscript/ch-1.ps |  77 +++++++++++++++
 challenge-211/roger-bell-west/postscript/ch-2.ps | 113 +++++++++++++++++++++++
 challenge-211/roger-bell-west/python/ch-1.py     |  34 +++++++
 challenge-211/roger-bell-west/python/ch-2.py     |  32 +++++++
 challenge-211/roger-bell-west/raku/ch-1.p6       |  36 ++++++++
 challenge-211/roger-bell-west/raku/ch-2.p6       |  29 ++++++
 challenge-211/roger-bell-west/ruby/ch-1.rb       |  43 +++++++++
 challenge-211/roger-bell-west/ruby/ch-2.rb       |  39 ++++++++
 challenge-211/roger-bell-west/rust/ch-1.rs       |  42 +++++++++
 challenge-211/roger-bell-west/rust/ch-2.rs       |  39 ++++++++
 challenge-211/roger-bell-west/tests.yaml         |  49 ++++++++++
 19 files changed, 956 insertions(+)
 create mode 100755 challenge-211/roger-bell-west/javascript/ch-1.js
 create mode 100755 challenge-211/roger-bell-west/javascript/ch-2.js
 create mode 100644 challenge-211/roger-bell-west/kotlin/ch-1.kt
 create mode 100644 challenge-211/roger-bell-west/kotlin/ch-2.kt
 create mode 100755 challenge-211/roger-bell-west/lua/ch-1.lua
 create mode 100755 challenge-211/roger-bell-west/lua/ch-2.lua
 create mode 100755 challenge-211/roger-bell-west/perl/ch-1.pl
 create mode 100755 challenge-211/roger-bell-west/perl/ch-2.pl
 create mode 100644 challenge-211/roger-bell-west/postscript/ch-1.ps
 create mode 100644 challenge-211/roger-bell-west/postscript/ch-2.ps
 create mode 100755 challenge-211/roger-bell-west/python/ch-1.py
 create mode 100755 challenge-211/roger-bell-west/python/ch-2.py
 create mode 100755 challenge-211/roger-bell-west/raku/ch-1.p6
 create mode 100755 challenge-211/roger-bell-west/raku/ch-2.p6
 create mode 100755 challenge-211/roger-bell-west/ruby/ch-1.rb
 create mode 100755 challenge-211/roger-bell-west/ruby/ch-2.rb
 create mode 100755 challenge-211/roger-bell-west/rust/ch-1.rs
 create mode 100755 challenge-211/roger-bell-west/rust/ch-2.rs
 create mode 100644 challenge-211/roger-bell-west/tests.yaml

(limited to 'challenge-211')

diff --git a/challenge-211/roger-bell-west/javascript/ch-1.js b/challenge-211/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..c400a681b4
--- /dev/null
+++ b/challenge-211/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,44 @@
+#! /usr/bin/node
+
+"use strict"
+
+function toeplitzmatrix(a) {
+    let ym = a.length - 1;
+    let xm = a[0].length - 1;
+    let toeplitz = true;
+    for (let xb = 1 - xm; xb <= ym - 1; xb++) {
+        let init = true;
+        let tv = 0;
+        for (let x = xb; x <= xb + xm; x++) {
+            if (x >= 0 && x <= xm) {
+                let y = x - xb;
+                if (y >= 0 && y <= ym) {
+                    if (init) {
+                        init = false;
+                        tv = a[y][x];
+                    } else if (a[y][x] != tv) {
+                        toeplitz = false;
+                        break;
+                    }
+                }
+            }
+        }
+        if (!toeplitz) {
+            break;
+        }
+    }
+    return toeplitz
+}
+
+if (toeplitzmatrix([[4, 3, 2, 1], [5, 4, 3, 2], [6, 5, 4, 3]])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (!toeplitzmatrix([[1, 2, 3], [3, 2, 1]])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-211/roger-bell-west/javascript/ch-2.js b/challenge-211/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..75870a79b1
--- /dev/null
+++ b/challenge-211/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,69 @@
+#! /usr/bin/node
+
+"use strict"
+
+function combinations(arr, k) {
+    let c = [];
+    for (let i = 0; i < k; i++) {
+        c.push(i);
+    }
+    c.push(arr.length);
+    c.push(0);
+    let out = [];
+    while (true) {
+        let inner = [];
+        for (let i = k-1; i >= 0; i--) {
+            inner.push(arr[c[i]]);
+        }
+        out.push(inner);
+        let j = 0;
+        while (c[j] + 1 == c[j + 1]) {
+            c[j] = j;
+            j += 1;
+        }
+        if (j >= k) {
+            break;
+        }
+        c[j] += 1;
+    }
+    return out;
+}
+
+function splitsameaverage(a) {
+    let ss = a.reduce((x, y) => x + y, 0);
+    let ml = a.length;
+    let mx = Math.floor(ml / 2);
+    let ssa = false;
+    for (let n = 1; n <= mx; n++) {
+        for (let c of combinations(a, n)) {
+            let ca = c.reduce((x, y) => x + y, 0);
+            if (ca / n == (ss - ca) / (ml - n)) {
+                ssa = true;
+                break;
+            }
+        }
+        if (ssa) {
+            break;
+        }
+    }
+    return ssa;
+}
+
+if (splitsameaverage([1, 2, 3, 4, 5, 6, 7, 8])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (!splitsameaverage([1, 3])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (splitsameaverage([1, 2, 3])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-211/roger-bell-west/kotlin/ch-1.kt b/challenge-211/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..96d2c4f559
--- /dev/null
+++ b/challenge-211/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,44 @@
+fun toeplitzmatrix(a: List<List<Int>>): Boolean {
+    val ym = a.size - 1
+    val xm = a[0].size - 1
+    var toeplitz = true
+    for (xb in 1 - xm .. ym - 1) {
+        var init = true
+        var tv = 0
+        for (x in xb .. xb + xm) {
+            if (x >= 0 && x <= xm) {
+                val y = x - xb
+                if (y >= 0 && y <= ym) {
+                    if (init) {
+                        init = false
+                        tv = a[y][x]
+                    } else if (a[y][x] != tv) {
+                        toeplitz = false
+                        break
+                    }
+                }
+            }
+        }
+        if (!toeplitz) {
+            break
+        }
+    }
+    return toeplitz
+}
+
+fun main() {
+
+    if (toeplitzmatrix(listOf(listOf(4, 3, 2, 1), listOf(5, 4, 3, 2), listOf(6, 5, 4, 3)))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (!toeplitzmatrix(listOf(listOf(1, 2, 3), listOf(3, 2, 1)))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-211/roger-bell-west/kotlin/ch-2.kt b/challenge-211/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..9145cbe67f
--- /dev/null
+++ b/challenge-211/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,69 @@
+fun combinations(arr: List<Int>, k: Int): List<List<Int>> {
+    var c = ArrayList<Int>()
+    for (i in 0 .. k-1) {
+        c.add(i)
+    }
+    c.add(arr.size)
+    c.add(0)
+    var out = ArrayList<List<Int>>()
+    while (true) {
+        var inner = ArrayList<Int>()
+        for (i in k-1 downTo 0) {
+            inner.add(arr[c[i]])
+        }
+        out.add(inner.toList())
+        var j = 0
+        while (c[j] + 1 == c[j + 1]) {
+            c[j] = j
+            j += 1
+        }
+        if (j >= k) {
+            break
+        }
+        c[j] += 1
+    }
+    return out.toList();
+}
+
+fun splitsameaverage(a: List<Int>): Boolean {
+    val ss = a.sum()
+    val ml = a.size
+    val mx = ml / 2
+    var ssa = false
+    for (n in 1 .. mx) {
+        for (c in combinations(a, n)) {
+            var ca = c.sum()
+            if (ca.toFloat() / n.toFloat() == (ss - ca).toFloat() / (ml - n).toFloat()) {
+                ssa = true
+                break
+            }
+        }
+        if (ssa) {
+            break
+        }
+    }
+    return ssa
+}
+
+fun main() {
+    
+    if (splitsameaverage(listOf(1, 2, 3, 4, 5, 6, 7, 8))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (!splitsameaverage(listOf(1, 3))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (splitsameaverage(listOf(1, 2, 3))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-211/roger-bell-west/lua/ch-1.lua b/challenge-211/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..50dfb58b1c
--- /dev/null
+++ b/challenge-211/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,46 @@
+#! /usr/bin/lua
+
+function toeplitzmatrix(a)
+   local ym = #a - 1
+   local xm = #(a[1]) - 1
+   local toeplitz = true
+   for xb = (1 - xm), (ym - 1) do
+      local init = true
+      local tv = 0
+      for xi = xb, xb + xm do
+         if xi >= 0 and xi <= xm then
+            local x = xi + 1
+            local yi = xi - xb
+            if yi >= 0 and yi <= ym then
+               local y = yi + 1
+               if init then
+                  init = false
+                  tv = a[y][x]
+               elseif a[y][x] ~= tv then
+                  toeplitz = false
+                  break
+               end
+            end
+         end
+      end
+      if not toeplitz then
+         break
+      end
+   end
+   return toeplitz
+end
+
+if toeplitzmatrix({{4, 3, 2, 1}, {5, 4, 3, 2}, {6, 5, 4, 3}}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if not toeplitzmatrix({{1, 2, 3}, {3, 2, 1}}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-211/roger-bell-west/lua/ch-2.lua b/challenge-211/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..c524e76c6d
--- /dev/null
+++ b/challenge-211/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,78 @@
+#! /usr/bin/lua
+
+function combinations(arr, k)
+   local c = {}
+   for i = 1, k do
+      table.insert(c, i)
+   end
+   table.insert(c, #arr + 1)
+   table.insert(c, 0)
+   local out = {}
+   while true do
+      local inner = {}
+      for i = k, 1, -1 do
+         table.insert(inner, arr[c[i]])
+      end
+      table.insert(out, inner)
+      local j = 1
+      while c[j] + 1 == c[j + 1] do
+         c[j] = j
+         j = j + 1
+      end
+      if j > k then
+