From cf099618b9fb98ac225c348e4c42e19b79dd67ab Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 8 Jan 2024 07:01:43 +0000
Subject: Challenge 251 Solutions (Raku)

---
 challenge-251/mark-anderson/raku/ch-1.raku | 11 ++++++
 challenge-251/mark-anderson/raku/ch-2.raku | 55 ++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 challenge-251/mark-anderson/raku/ch-1.raku
 create mode 100644 challenge-251/mark-anderson/raku/ch-2.raku

diff --git a/challenge-251/mark-anderson/raku/ch-1.raku b/challenge-251/mark-anderson/raku/ch-1.raku
new file mode 100644
index 0000000000..6b938ecd27
--- /dev/null
+++ b/challenge-251/mark-anderson/raku/ch-1.raku
@@ -0,0 +1,11 @@
+#!/usr/bin/env raku
+use Test;
+
+is concat-val([6,12,25,1]),     1286;
+is concat-val([10,7,31,5,2,2]), 489;
+is concat-val([1,2,10]),        112;
+
+sub concat-val(@a)
+{
+    [+] map { @a.shift ~ (@a.pop || Empty) }, ^(@a / 2)
+}
diff --git a/challenge-251/mark-anderson/raku/ch-2.raku b/challenge-251/mark-anderson/raku/ch-2.raku
new file mode 100644
index 0000000000..eede360155
--- /dev/null
+++ b/challenge-251/mark-anderson/raku/ch-2.raku
@@ -0,0 +1,55 @@
+#!/usr/bin/env raku
+use Test;
+
+is-deeply (15,), lucky-numbers([
+                                   [  3,  7,  8 ],
+                                   [  9, 11, 13 ],
+                                   [ 15, 16, 17 ]
+                               ]);
+
+is-deeply (12,), lucky-numbers([ 
+                                   [  1, 10,  4,  2 ],
+                                   [  9,  3,  8,  7 ],
+                                   [ 15, 16, 17, 12 ] 
+                               ]);
+
+is-deeply (7,),  lucky-numbers([
+                                   [ 7, 8 ],
+                                   [ 1, 2 ]
+                               ]);
+
+is-deeply (16,), lucky-numbers([
+                                   [ 22,  4, 20, 24 ],
+                                   [ 21, 16, 23, 18 ],
+                                   [  3, 12, 19,  5 ],
+                                   [ 15,  7, 10,  2 ],
+                                   [ 17, 11,  6, 13 ],
+                                   [  9,  8, 14,  1 ]
+                               ]);
+
+is-deeply (),    lucky-numbers([
+                                   [ 26, 50, 10, 54, 42, 31, 45, 58 ],
+                                   [ 29, 64, 23, 35, 15, 41, 27, 17 ],
+                                   [ 55, 37,  1, 30, 52, 53, 21, 46 ],
+                                   [  3,  2,  6, 36, 11, 13, 19, 22 ],
+                                   [ 61, 47, 32, 39, 49, 62,  9, 12 ],
+                                   [ 20, 60, 44,  7, 59, 34, 14, 16 ],
+                                   [  8, 24, 38, 43, 56, 48, 57, 25 ],
+                                   [  5, 40, 33, 28, 63, 18,  4, 51 ]
+                               ]);
+
+is-deeply (43,), lucky-numbers([
+                                   [ 34,  2, 9,  53, 32, 29, 36, 30 ],
+                                   [  7, 19, 24, 10, 26, 27, 31, 25 ],
+                                   [ 52, 50, 39, 11, 22,  1, 54, 62 ],
+                                   [ 45, 56, 59, 20, 37, 17, 40, 42 ],
+                                   [ 14,  8, 63, 46,  5, 44, 61,  3 ],
+                                   [ 38, 15, 18, 16,  6, 12, 60,  4 ],
+                                   [ 41, 23, 13, 21, 35, 33, 28, 51 ],
+                                   [ 58, 48, 49, 55, 43, 47, 64, 57 ]
+                               ]);
+
+sub lucky-numbers(@m)
+{
+    keys (@m>>.min (&) ([Z] @m)>>.max)
+}
-- 
cgit 


From 2d8482e6a6c66e41be970509f8b1b25afe0df9aa Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 8 Jan 2024 07:15:12 +0000
Subject: Challenge 251 Solutions (Raku)

---
 challenge-251/mark-anderson/raku/ch-2.raku | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/challenge-251/mark-anderson/raku/ch-2.raku b/challenge-251/mark-anderson/raku/ch-2.raku
index eede360155..635e8aa611 100644
--- a/challenge-251/mark-anderson/raku/ch-2.raku
+++ b/challenge-251/mark-anderson/raku/ch-2.raku
@@ -51,5 +51,5 @@ is-deeply (43,), lucky-numbers([
 
 sub lucky-numbers(@m)
 {
-    keys (@m>>.min (&) ([Z] @m)>>.max)
+    keys @m>>.min (&) ([Z] @m)>>.max
 }
-- 
cgit 


From 460fd6dd4635df456cb82978c5ab1e4b925deae0 Mon Sep 17 00:00:00 2001
From: Michael Manring <michael@manring>
Date: Mon, 8 Jan 2024 19:35:52 +1100
Subject: pwc251 solution in python

---
 challenge-251/pokgopun/python/ch-1.py | 88 +++++++++++++++++++++++++++++++++++
 challenge-251/pokgopun/python/ch-2.py | 78 +++++++++++++++++++++++++++++++
 2 files changed, 166 insertions(+)
 create mode 100644 challenge-251/pokgopun/python/ch-1.py
 create mode 100644 challenge-251/pokgopun/python/ch-2.py

diff --git a/challenge-251/pokgopun/python/ch-1.py b/challenge-251/pokgopun/python/ch-1.py
new file mode 100644
index 0000000000..41fd8c1c0c
--- /dev/null
+++ b/challenge-251/pokgopun/python/ch-1.py
@@ -0,0 +1,88 @@
+### https://theweeklychallenge.org/blog/perl-weekly-challenge-251/
+"""
+
+Task 1: Concatenation Value
+
+Submitted by: [52]Mohammad S Anwar
+     __________________________________________________________________
+
+   You are given an array of integers, @ints.
+
+   Write a script to find the concatenation value of the given array.
+
+   The concatenation of two numbers is the number formed by concatenating
+   their numerals.
+For example, the concatenation of 10, 21 is 1021.
+The concatenation value of @ints is initially equal to 0.
+Perform this operation until @ints becomes empty:
+
+If there exists more than one number in @ints, pick the first element
+and last element in @ints respectively and add the value of their
+concatenation to the concatenation value of @ints, then delete the
+first and last element from @ints.
+
+If one element exists, add its value to the concatenation value of
+@ints, then delete it.
+
+Example 1
+
+Input: @ints = (6, 12, 25, 1)
+Output: 1286
+
+1st operation: concatenation of 6 and 1 is 61
+2nd operation: concaternation of 12 and 25 is 1225
+
+Concatenation Value => 61 + 1225 => 1286
+
+Example 2
+
+Input: @ints = (10, 7, 31, 5, 2, 2)
+Output: 489
+
+1st operation: concatenation of 10 and 2 is 102
+2nd operation: concatenation of 7 and 2 is 72
+3rd operation: concatenation of 31 and 5 is 315
+
+Concatenation Value => 102 + 72 + 315 => 489
+
+Example 3
+
+Input: @ints = (1, 2, 10)
+Output: 112
+
+1st operation: concatenation of 1 and 10 is 110
+2nd operation: only element left is 2
+
+Concatenation Value => 110 + 2 => 112
+
+Task 2: Lucky Numbers
+"""
+### solution by pokgopun@gmail.com
+
+def concatenation(tup: tuple):
+    #print(tup)
+    l = len(tup)
+    sum = 0
+    for i in range(l//2):
+        #print(tup[i],tup[l-1-i],"=>",int(str(tup[i])+str(tup[l-1-i])))
+        sum += int(str(tup[i])+str(tup[l-1-i]))
+    if l % 2:
+        #print("addition",tup[l//2])
+        sum += tup[l//2]
+    return sum
+
+import unittest
+
+class TestConcatenation(unittest.TestCase):
+    def test(self):
+        for inpt,otpt in {
+                (6, 12, 25, 1): 1286,
+                (10, 7, 31, 5, 2, 2): 489,
+                (1, 2, 10): 112,
+                }.items():
+            self.assertEqual(concatenation(inpt),otpt)
+
+unittest.main()
+
+
+
diff --git a/challenge-251/pokgopun/python/ch-2.py b/challenge-251/pokgopun/python/ch-2.py
new file mode 100644
index 0000000000..c987d9f4df
--- /dev/null
+++ b/challenge-251/pokgopun/python/ch-2.py
@@ -0,0 +1,78 @@
+### https://theweeklychallenge.org/blog/perl-weekly-challenge-251/
+"""
+
+Task 2: Lucky Numbers
+
+Submitted by: [53]Mohammad S Anwar
+     __________________________________________________________________
+
+   You are given a m x n matrix of distinct numbers.
+
+   Write a script to return the lucky number, if there is one, or -1 if
+   not.
+A lucky number is an element of the matrix such that it is
+the minimum element in its row and maximum in its column.
+
+Example 1
+
+Input: $matrix = [ [ 3,  7,  8],
+                   [ 9, 11, 13],
+                   [15, 16, 17] ];
+Output: 15
+
+15 is the only lucky number since it is the minimum in its row
+and the maximum in its column.
+
+Example 2
+
+Input: $matrix = [ [ 1, 10,  4,  2],
+                   [ 9,  3,  8,  7],
+                   [15, 16, 17, 12] ];
+Output: 12
+
+Example 3
+
+Input: $matrix = [ [7 ,8],
+                   [1 ,2] ];
+Output: 7
+     __________________________________________________________________
+
+   Last date to submit the solution 23:59 (UK Time) Sunday 14th January
+   2024.
+     __________________________________________________________________
+
+SO WHAT DO YOU THINK ?
+"""
+### solution by pokgopun@gmail.com
+
+def luckynumber(tup: list):
+    #print(tup)
+    res = -1
+    for i in range(len(tup)):
+        mn = min(tup[i])
+        #print("mn =",mn)
+        j = tup[i].index(mn)
+        if mn == max(e[j] for e in tup):
+            res = mn
+            break
+    return res
+
+import unittest
+
+class TestLuckynumber(unittest.TestCase):
+    def test(self):
+        for inpt,otpt in {
+                ( ( 3,  7,  8),
+                   ( 9, 11, 13),
+                   (15, 16, 17) ): 15,
+                ( ( 1, 10,  4,  2),
+                   ( 9,  3,  8,  7),
+                   (15, 16, 17, 12) ): 12,
+                ( (7 ,8),
+                   (1 ,2) ): 7,
+                }.items():
+            self.assertEqual(luckynumber(inpt),otpt)
+
+unittest.main()
+
+ 
-- 
cgit 


From 275425a6539c092ed817bba98f9bf3bf910f4897 Mon Sep 17 00:00:00 2001
From: Scimon <simon.proctor@gmail.com>
Date: Mon, 8 Jan 2024 10:10:08 +0000
Subject: Challenge 251

---
 challenge-251/simon-proctor/raku/ch-1.raku | 28 +++++++++++++++++++++
 challenge-251/simon-proctor/raku/ch-2.raku | 40 ++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 challenge-251/simon-proctor/raku/ch-1.raku
 create mode 100644 challenge-251/simon-proctor/raku/ch-2.raku

diff --git a/challenge-251/simon-proctor/raku/ch-1.raku b/challenge-251/simon-proctor/raku/ch-1.raku
new file mode 100644
index 0000000000..a85d9e7171
--- /dev/null
+++ b/challenge-251/simon-proctor/raku/ch-1.raku
@@ -0,0 +1,28 @@
+#!/usr/bin/env raku
+
+#| Run Test Suite
+multi sub MAIN('test') {
+    use Test;
+    is concat-number(6, 12, 25, 1), 1286;
+    is concat-number(10, 7, 31, 5, 2, 2), 489;
+    is concat-number(1, 2, 10), 112;
+    done-testing;
+}
+
+#| Print the concatentaion number
+multi sub MAIN(
+    *@vals where all(@vals) ~~ IntStr #= List of ints
+) {
+    concat-number( |@vals ).say;
+}
+
+sub concat-number( *@vals ) {
+    my $total = 0;
+    while (@vals.elems > 1) {
+        my $f = @vals.shift;
+        my $l = @vals.pop;
+        $total += ($f ~ $l);
+    }
+    $total += @vals[0] if @vals.elems == 1;
+    return $total;
+}
diff --git a/challenge-251/simon-proctor/raku/ch-2.raku b/challenge-251/simon-proctor/raku/ch-2.raku
new file mode 100644
index 0000000000..e5f95f5216
--- /dev/null
+++ b/challenge-251/simon-proctor/raku/ch-2.raku
@@ -0,0 +1,40 @@
+#!/usr/bin/env raku
+
+#| Run the Test Suite
+multi sub MAIN('test') {
+    use Test;
+    is-deeply rot-matrix([[1,2],[3,4]]), [[1,3],[2,4]];
+    is lucky( [[3,7,8],[9,11,13],[15,16,17]] ), 15;
+    is lucky( [[1,10,4,2],[9,3,8,7],[15,16,17,12]] ), 12;
+    is lucky( [[7,8],[1,2]] ), 7;
+    is lucky( [[1,2],[3,4]] ), 3;
+    done-testing;
+}
+
+multi sub MAIN(
+    Int $width, #= Matrix width
+    *@vals where @vals.unique.elems == @vals.elems && all(@vals) ~~ IntStr, #= Matrix values
+) {
+    my @matrix = @vals.rotor($width);
+    lucky(@matrix).say;
+}
+
+sub rot-matrix( @matrix ) {
+    my @out;
+    for (^@matrix.elems) -> $i {
+        for (^@matrix[0].elems) -> $j {
+            @out[$j] //= [];
+            @out[$j][$i] = @matrix[$i][$j];
+        }
+    }
+    return @out;
+}
+
+sub lucky( @matrix ) {
+    my @rot = rot-matrix(@matrix);
+    my @mins = @matrix.map( *.min );
+    my @maxs = @rot.map( *.max );
+    my $int = @mins ∩ @maxs;
+    return -1 unless $int.keys.elems == 1;
+    return $int.keys[0];
+}
-- 
cgit 


From 9ba7d42d06bfcfa6762c442611c9d84a01a422ca Mon Sep 17 00:00:00 2001
From: Scimon <simon.proctor@gmail.com>
Date: Mon, 8 Jan 2024 10:11:42 +0000
Subject: Challenge 251 (Small updateto part 2)

---
 challenge-251/simon-proctor/raku/ch-2.raku | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/challenge-251/simon-proctor/raku/ch-2.raku b/challenge-251/simon-proctor/raku/ch-2.raku
index e5f95f5216..17ae44be46 100644
--- a/challenge-251/simon-proctor/raku/ch-2.raku
+++ b/challenge-251/simon-proctor/raku/ch-2.raku
@@ -13,7 +13,9 @@ multi sub MAIN('test') {
 
 multi sub MAIN(
     Int $width, #= Matrix width
-    *@vals where @vals.unique.elems == @vals.elems && all(@vals) ~~ IntStr, #= Matrix values
+    *@vals where @vals.unique.elems == @vals.elems #= Matrix values
+                 && all(@vals) ~~ IntStr
+                 && @vals.elems %% $width, 
 ) {
     my @matrix = @vals.rotor($width);
     lucky(@matrix).say;
-- 
cgit 


From 080fde56fb9825f48e63c97840234fbde25fedaa Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 8 Jan 2024 10:17:22 +0100
Subject: PWC 251

Task 1 Raku done
Task 2 Raku done

Task 1 PL/Perl done
Task 2 PL/perl done

Task 1 PL/PgSQL done
Task 2 PL/PgSQL done

Task 1 Python done
Task 2 Python done
---
 challenge-251/luca-ferrari/blog-1.txt             |  1 +
 challenge-251/luca-ferrari/blog-2.txt             |  1 +
 challenge-251/luca-ferrari/blog-3.txt             |  1 +
 challenge-251/luca-ferrari/blog-4.txt             |  1 +
 challenge-251/luca-ferrari/blog-5.txt             |  1 +
 challenge-251/luca-ferrari/blog-6.txt             |  1 +
 challenge-251/luca-ferrari/blog-7.txt             |  1 +
 challenge-251/luca-ferrari/blog-8.txt             |  1 +
 challenge-251/luca-ferrari/postgresql/ch-1.plperl | 23 +++++++++
 challenge-251/luca-ferrari/postgresql/ch-1.sql    | 29 +++++++++++
 challenge-251/luca-ferrari/postgresql/ch-2.plperl | 63 +++++++++++++++++++++++
 challenge-251/luca-ferrari/postgresql/ch-2.sql    | 16 ++++++
 challenge-251/luca-ferrari/python/ch-1.py         | 25 +++++++++
 challenge-251/luca-ferrari/python/ch-2.py         | 59 +++++++++++++++++++++
 challenge-251/luca-ferrari/raku/ch-1.p6           | 17 ++++++
 challenge-251/luca-ferrari/raku/ch-2.p6           | 37 +++++++++++++
 16 files changed, 277 insertions(+)
 create mode 100644 challenge-251/luca-ferrari/blog-1.txt
 create mode 100644 challenge-251/luca-ferrari/blog-2.txt
 create mode 100644 challenge-251/luca-ferrari/blog-3.txt
 create mode 100644 challenge-251/luca-ferrari/blog-4.txt
 create mode 100644 challenge-251/luca-ferrari/blog-5.txt
 create mode 100644 challenge-251/luca-ferrari/blog-6.txt
 create mode 100644 challenge-251/luca-ferrari/blog-7.txt
 create mode 100644 challenge-251/luca-ferrari/blog-8.txt
 create mode 100644 challenge-251/luca-ferrari/postgresql/ch-1.plperl
 create mode 100644 challenge-251/luca-ferrari/postgresql/ch-1.sql
 create mode 100644 challenge-251/luca-ferrari/postgresql/ch-2.plperl
 create mode 100644 challenge-251/luca-ferrari/postgresql/ch-2.sql
 create mode 100644 challenge-251/luca-ferrari/python/ch-1.py
 create mode 100644 challenge-251/luca-ferrari/python/ch-2.py
 create mode 100644 challenge-251/luca-ferrari/raku/ch-1.p6
 create mode 100644 challenge-251/luca-ferrari/raku/ch-2.p6

diff --git a/challenge-251/luca-ferrari/blog-1.txt b/challenge-251/luca-ferrari/blog-1.txt
new file mode 100644
index 0000000000..ef5631ba42
--- /dev/null
+++ b/challenge-251/luca-ferrari/blog-1.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/01/08/PerlWeeklyChallenge251.html#task1
diff --git a/challenge-251/luca-ferrari/blog-2.txt b/challenge-251/luca-ferrari/blog-2.txt
new file mode 100644
index 0000000000..40f36701a6
--- /dev/null
+++ b/challenge-251/luca-ferrari/blog-2.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/01/08/PerlWeeklyChallenge251.html#task2
diff --git a/challenge-251/luca-ferrari/blog-3.txt b/challenge-251/luca-ferrari/blog-3.txt
new file mode 100644
index 0000000000..d8cf826c69
--- /dev/null
+++ b/challenge-251/luca-ferrari/blog-3.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/01/08/PerlWeeklyChallenge251.html#task1plperl
diff --git a/challenge-251/luca-ferrari/blog-4.txt b/challenge-251/luca-ferrari/blog-4.txt
new file mode 100644
index 0000000000..8bc8154b8b
--- /dev/null
+++ b/challenge-251/luca-ferrari/blog-4.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/01/08/PerlWeeklyChallenge251.html#task2plperl
diff --git a/challenge-251/luca-ferrari/blog-5.txt b/challenge-251/luca-ferrari/blog-5.txt
new file mode 100644
index 0000000000..e8326a85ec
--- /dev/null
+++ b/challenge-251/luca-ferrari/blog-5.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/01/08/PerlWeeklyChallenge251.html#task1plpgsql
diff --git a/challenge-251/luca-ferrari/blog-6.txt b/challenge-251/luca-ferrari/blog-6.txt
new file mode 100644
index 0000000000..57b87c236c
--- /dev/null
+++ b/challenge-251/luca-ferrari/blog-6.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/01/08/PerlWeeklyChallenge251.html#task2plpgsql
diff --git a/challenge-251/luca-ferrari/blog-7.txt b/challenge-251/luca-ferrari/blog-7.txt
new file mode 100644
index 0000000000..9437b6564e
--- /dev/null
+++ b/challenge-251/luca-ferrari/blog-7.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/01/08/PerlWeeklyChallenge251.html#task1python
diff --git a/challenge-251/luca-ferrari/blog-8.txt b/challenge-251/luca-ferrari/blog-8.txt
new file mode 100644
index 0000000000..f653f319b0
--- /dev/null
+++ b/challenge-251/luca-ferrari/blog-8.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/01/08/PerlWeeklyChallenge251.html#task2python
diff --git a/challenge-251/luca-ferrari/postgresql/ch-1.plperl b/challenge-251/luca-ferrari/postgresql/ch-1.plperl
new file mode 100644
index 0000000000..7152e60c8a
--- /dev/null
+++ b/challenge-251/luca-ferrari/postgresql/ch-1.plperl
@@ -0,0 +1,23 @@
+--
+-- Perl Weekly Challenge 251
+-- Task 1
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-251/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc251;
+
+CREATE OR REPLACE FUNCTION
+pwc251.task1_plperl( int[] )
+RETURNS int
+AS $CODE$
+   my ( $nums ) = @_;
+   my $sum = 0;
+   
+   for  ( 0 .. $nums->@* - 2 ) {
+	next if $_ % 2 != 0;
+        $sum += $nums->@[ $_ ] . $nums->@[ $_ + 1 ];
+   }
+
+   return $sum;
+$CODE$
+LANGUAGE plperl;
diff --git a/challenge-251/luca-ferrari/postgresql/ch-1.sql b/challenge-251/luca-ferrari/postgresql/ch-1.sql
new file mode 100644
index 0000000000..83c215c5f6
--- /dev/null
+++ b/challenge-251/luca-ferrari/postgresql/ch-1.sql
@@ -0,0 +1,29 @@
+--
+-- Perl Weekly Challenge 251
+-- Task 1
+--
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-251/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc251;
+
+CREATE OR REPLACE FUNCTION
+pwc251.task1_plpgsql( nums int[] )
+RETURNS int
+AS $CODE$
+DECLARE
+	s text;
+	v int := 0;
+BEGIN
+	FOR i IN 1 .. array_length( nums, 1 ) - 1 LOOP
+	    IF i % 2 = 0 THEN
+	       CONTINUE;
+	    END IF;
+
+	    v := v + ( nums[ i ]::text || nums[ i + 1 ]::text )::int;
+	END LOOP;
+
+	RETURN v;
+END
+$CODE$
+LANGUAGE plpgsql;
diff --git a/challenge-251/luca-ferrari/postgresql/ch-2.plperl b/challenge-251/luca-ferrari/postgresql/ch-2.plperl
new file mode 100644
index 0000000000..32d43ba6ef
--- /dev/null
+++ b/challenge-251/luca-ferrari/postgresql/ch-2.plperl
@@ -0,0 +1,63 @@
+--
+-- Perl Weekly Challenge 251
+-- Task 2
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-251/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc251;
+
+/**
+ * example
+ testdb=> select pwc251.task2_plperl( array[ [ 3,  7,  8],
+                   [ 9, 11, 13],
+                   [15, 16, 17]] );
+ task2_plperl 
+--------------
+           15
+(1 row)
+*/
+CREATE OR REPLACE FUNCTION
+pwc251.task2_plperl( int[][] )
+RETURNS int
+AS $CODE$
+   my ( $matrix ) = @_;
+
+   my $max_col = undef;
+
+   # search the max column value
+   my @max_col_indexes;
+   for my $col ( 0 .. $matrix->@[ 0 ]->@* - 1 ) {
+       $max_col_index[ $col ] = undef;
+
+       for my $row ( 0 .. $matrix->@* - 1 ) {
+       	   $max_col_index[ $col ] = $matrix->@[ $row ]->[ $col ] if ( ! $max_col_index[ $col ] || $max_col_index[ $col ] < $matrix->@[ $row ]->[ $col ] );
+       }
+   }
+   for my $row ( 0 .. $matrix->@* - 1 ) {
+       for my $col ( 0 .. $matrix->@[ $row ]->@* - 1 ) {
+       	   $max_col = $matrix->@[ $row ]->[ $col ] if ( ! $max_col || $max_col < $matrix->@[ $row ]->[ $col ] );
+       }
+   }
+
+  for my $row ( 0 .. $matrix->@* - 1 ) {
+      my $current_min = undef;
+      my $current_min_index = 0;
+      
+     for my $col ( 0 .. $matrix->@[ $row ]->@* - 1 ) {
+     	 if ( ! $current_min || $matrix->@[ $row ]->[ $col ] < $current_min ) {
+	    $current_min = $matrix->@[ $row ]->[ $col ];
+	    $current_min_index = $col;
+	 }
+     }
+
+     if ( $current_min == $max_col_index[ $current_min_index ] ) {
+     	return $current_min;
+     }
+
+
+  }
+
+  return -1;
+
+$CODE$
+LANGUAGE plperl;
diff --git a/challenge-251/luca-ferrari/postgresql/ch-2.sql b/challenge-251/luca-ferrari/postgresql/ch-2.sql
new file mode 100644
index 0000000000..fcdf6a6f9a
--- /dev/null
+++ b/challenge-251/luca-ferrari/postgresql/ch-2.sql
@@ -0,0 +1,16 @@
+--
+-- Perl Weekly Challenge 251
+-- Task 2
+--
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-251/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc251;
+
+CREATE OR REPLACE FUNCTION
+pwc251.task2_plpgsql( matrix int[][] )
+RETURNS int
+AS $CODE$
+   SELECT pwc251.task2_plperl( matrix );
+$CODE$
+LANGUAGE sql;
diff --git a/challenge-251/luca-ferrari/python/ch-1.py b/challenge-251/luca-ferrari/python/ch-1.py
new file mode 100644
index 0000000000..e72f979066
--- /dev/null
+++ b/challenge-251/luca-ferrari/python/ch-1.py
@@ -0,0 +1,25 @@
+#!python
+
+#
+# Perl Weekly Challenge 251
+# Task 1
+#
+# See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-251/>
+#
+
+import sys
+
+# task implementation
+def main( argv ):
+    sum = 0
+    for i in range( 0, len( argv ) - 1 ):
+        if i % 2 != 0:
+            continue
+        sum += int( argv[ i ] + argv[ i + 1 ] )
+
+    return sum
+
+
+# invoke the main without the command itself
+if __name__ == '__main__':
+    print( main( sys.argv[ 1: ] ) )
diff --git a/challenge-251/luca-ferrari/python/ch-2.py b/challenge-251/luca-ferrari/python/ch-2.py
new file mode 100644
index 0000000000..a06c706b28
--- /dev/null
+++ b/challenge-251/luca-ferrari/python/ch-2.py
@@ -0,0 +1,59 @@
+#!python
+
+#
+# Perl Weekly Challenge 251
+# Task 2
+#
+# See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-251/>
+#
+
+import sys
+
+# task implementation
+def main( argv ):
+    matrix = []
+    row = 0
+    matrix.append( [] )
+
+    for x in argv[ 0 ]:
+        if x == ' ':
+            continue
+
+        # change row
+        if x == '|':
+            row += 1
+            matrix.append( [] )
+            continue
+
+        matrix[ row ].append( int( x ) )
+
+    # make indexes of max columns
+    max_cols = []
+    for col in range( 0, len( matrix ) ):
+        current_max = None
+        for row in range( 0, len( matrix[ 0 ] ) ):
+            if not current_max or current_max < matrix[ row ][ col ] :
+                current_max = matrix[ row ][ col ]
+
+        max_cols.append( current_max )
+
+    for row in range( 0, len( matrix ) ):
+        current_min = None
+        current_min_col = None
+
+        for col in range( 0, len( matrix[ row ] ) ):
+            if not current_min or current_min > matrix[ row ][ col ]:
+                current_min = matrix[ row ][ col ]
+                current_min_col = col
+
+        if current_min == max_cols[ current_min_col ]:
+            return current_min
+
+    return -1
+
+
+
+
+# invoke the main without the command itself
+if __name__ == '__main__':
+    print( main( sys.argv[ 1: ] ) )
diff --git a/challenge-251/luca-ferrari/raku/ch-1.p6 b/challenge-251/luca-ferrari/raku/ch-1.p6
new file mode 100644
index 0000000000..c0ba780273
--- /dev/null
+++ b/challenge-251/luca-ferrari/raku/ch-1.p6
@@ -0,0 +1,17 @@
+#!raku
+
+#
+# Perl Weekly Challenge 251
+# Task 1
+#
+# See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-251/>
+#
+
+sub MAIN( *@nums where { @nums.elems == @nums.grep( * ~~ Int ).elems and @nums.elems %% 2 } ) {
+    my $sum = 0;
+    for @nums -> $l, $r {
+	$sum += $l ~ $r;
+    }
+
+    $sum.say;
+}
diff --git a/challenge-251/luca-ferrari/raku/ch-2.p6 b/challenge-251/luca-ferrari/raku/ch-2.p6
new file mode 100644
index 0000000000..cbfdd4baab
--- /dev/null
+++ b/challenge-251/luca-ferrari/raku/ch-2.p6
@@ -0,0 +1,37 @@
+#!raku
+
+#
+# Perl Weekly Challenge 251
+# Task 2
+#
+# See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-251/>
+#
+
+sub MAIN() {
+
+    my $matrix = [ [ 3,  7,  8],
+                   [ 9, 11, 13],
+                   [15, 16, 17] ];
+
+    my @max-col;
+    for 0 ..^ $matrix[ 0 ].elems -> $col {
+	my @current-col.push: $matrix[ $_ ][ $col ] for 0 ..^ $matrix.elems;
+	@max-col[ $col ] = @current-col.max;
+    }
+
+    for 0 ..^ $matrix.elems -> $row {
+	my $min = Nil;
+	my $min-col = Nil;
+
+	for 0 ..^ $matrix[ $row ].elems -> $col {
+	    if ( ! $min ||  $matrix[ $row ][ $col ] < $min ) {
+		$min-col = $col;
+		$min = $matrix[ $row ][ $col ];
+	    }
+	}
+
+	$min.say and exit if ( @max-col[ $min-col ] == $min );
+    }
+
+    '-1'.say;
+}
-- 
cgit 


From 2f0103fc32a161b83ebfbc34b7ccce5d26200d45 Mon Sep 17 00:00:00 2001
From: Thomas Köhler <jean-luc@picard.franken.de>
Date: Mon, 8 Jan 2024 11:31:26 +0100
Subject: Add solution 251
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Thomas Köhler <jean-luc@picard.franken.de>
---
 challenge-251/jeanluc2020/blog-1.txt     |  1 +
 challenge-251/jeanluc2020/blog-2.txt     |  1 +
 challenge-251/jeanluc2020/perl/ch-1.pl   | 95 ++++++++++++++++++++++++++++++++
 challenge-251/jeanluc2020/perl/ch-2.pl   | 95 ++++++++++++++++++++++++++++++++
 challenge-251/jeanluc2020/python/ch-1.py | 87 +++++++++++++++++++++++++++++
 challenge-251/jeanluc2020/python/ch-2.py | 82 +++++++++++++++++++++++++++
 6 files changed, 361 insertions(+)
 create mode 100644 challenge-251/jeanluc2020/blog-1.txt
 create mode 100644 challenge-251/jeanluc2020/blog-2.txt
 create mode 100755 challenge-251/jeanluc2020/perl/ch-1.pl
 create mode 100755 challenge-251/jeanluc2020/perl/ch-2.pl
 create mode 100755 challenge-251/jeanluc2020/python/ch-1.py
 create mode 100755 challenge-251/jeanluc2020/python/ch-2.py

diff --git a/challenge-251/jeanluc2020/blog-1.txt b/challenge-251/jeanluc2020/blog-1.txt
new file mode 100644
index 0000000000..26c059d208
--- /dev/null
+++ b/challenge-251/jeanluc2020/blog-1.txt
@@ -0,0 +1 @@
+http://gott-gehabt.de/800_wer_wir_sind/thomas/Homepage/Computer/perl/theweeklychallenge-251-1.html
diff --git a/challenge-251/jeanluc2020/blog-2.txt b/challenge-251/jeanluc2020/blog-2.txt
new file mode 100644
index 0000000000..9816093212
--- /dev/null
+++ b/challenge-251/jeanluc2020/blog-2.txt
@@ -0,0 +1 @@
+http://gott-gehabt.de/800_wer_wir_sind/thomas/Homepage/Computer/perl/theweeklychallenge-251-2.html
diff --git a/challenge-251/jeanluc2020/perl/ch-1.pl b/challenge-251/jeanluc2020/perl/ch-1.pl
new file mode 100755
index 0000000000..64648b97c2
--- /dev/null
+++ b/challenge-251/jeanluc2020/perl/ch-1.pl
@@ -0,0 +1,95 @@
+#!/usr/bin/perl
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-251/#TASK1
+#
+# Task 1: Concatenation Value
+# ===========================
+#
+# You are given an array of integers, @ints.
+#
+# Write a script to find the concatenation value of the given array.
+#
+# The concatenation of two numbers is the number formed by concatenating their
+# numerals.
+#
+## For example, the concatenation of 10, 21 is 1021.
+## The concatenation value of @ints is initially equal to 0.
+## Perform this operation until @ints becomes empty:
+##
+## If there exists more than one number in @ints, pick the first element
+## and last element in @ints respectively and add the value of their
+## concatenation to the concatenation value of @ints, then delete the
+## first and last element from @ints.
+##
+## If one element exists, add its value to the concatenation value of
+## @ints, then delete it.
+#
+## Example 1
+##
+## Input: @ints = (6, 12, 25, 1)
+## Output: 1286
+##
+## 1st operation: concatenation of 6 and 1 is 61
+## 2nd operation: concaternation of 12 and 25 is 1225
+##
+## Concatenation Value => 61 + 1225 => 1286
+#
+## Example 2
+##
+## Input: @ints = (10, 7, 31, 5, 2, 2)
+## Output: 489
+##
+## 1st operation: concatenation of 10 and 2 is 102
+## 2nd operation: concatenation of 7 and 2 is 72
+## 3rd operation: concatenation of 31 and 5 is 315
+##
+## Concatenation Value => 102 + 72 + 315 => 489
+#
+## Example 3
+##
+## Input: @ints = (1, 2, 10)
+## Output: 112
+##
+## 1st operation: concatenation of 1 and 10 is 110
+## 2nd operation: only element left is 2
+##
+## Concatenation Value => 110 + 2 => 112
+#
+############################################################
+##
+## discussion
+##
+############################################################
+#
+# Starting with a sum of 0, we call a function that just concatenates
+# the first and last elements of @ints and adds that number to the
+# current sum, then we call the function recursively with the new
+# current sum and the remainder of the array. Of course handle the
+# case where there is only one element in the array by returning the
+# current sum + the last element, and the case of an empty array by
+# returning the current sum.
+
+use strict;
+use warnings;
+
+concatenation_value(6, 12, 25, 1);
+concatenation_value(10, 7, 31, 5, 2, 2);
+concatenation_value(1, 2, 10);
+
+sub concatenation_value {
+   my @ints = @_;
+   print "Input: (" . join(", ", @ints) . ")\n";
+   my $result = concatenation_value_(0, @ints);
+   print "Output: $result\n";
+}
+
+sub concatenation_value_ {
+   my ($current, @ints) = @_;
+   return $current unless @ints;
+   if(@ints >= 2) {
+      my $first = shift @ints;
+      my $last = pop @ints;
+      return concatenation_value_($current + "$first$last", @ints);
+   } else {
+      return $current + $ints[0];
+   }
+}
diff --git a/challenge-251/jeanluc2020/perl/ch-2.pl b/challenge-251/jeanluc2020/perl/ch-2.pl
new file mode 100755
index 0000000000..6c41933c38
--- /dev/null
+++ b/challenge-251/jeanluc2020/perl/ch-2.pl
@@ -0,0 +1,95 @@
+#!/usr/bin/perl
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-251/#TASK2
+#
+# Task 2: Lucky Numbers
+# =====================
+#
+# You are given a m x n matrix of distinct numbers.
+#
+# Write a script to return the lucky number, if there is one, or -1 if not.
+#
+## A lucky number is an element of the matrix such that it is
+## the minimum element in its row and maximum in its column.
+#
+## Example 1
+##
+## Input: $matrix = [ [ 3,  7,  8],
+##                    [ 9, 11, 13],
+##                    [15, 16, 17] ];
+## Output: 15
+##
+## 15 is the only lucky number since it is the minimum in its row
+## and the maximum in its column.
+#
+## Example 2
+##
+## Input: $matrix = [ [ 1, 10,  4,  2],
+##                    [ 9,  3,  8,  7],
+##                    [15, 16, 17, 12] ];
+## Output: 12
+#
+## Example 3
+##
+## Input: $matrix = [ [7 ,8],
+##                    [1 ,2] ];
+## Output: 7
+#
+############################################################
+##
+## discussion
+##
+############################################################
+#
+# For a lucky number, we know:
+# Since the minimum in a row is at the same time the maximum in
+# a column, there is no number bigger in that column, so in all
+# other rows, there is a number that is smaller than the current
+# number, so the minimum in that other row has to be smaller or
+# equal to this number; being smaller, it can't be bigger than any
+# of the numbers in the original row, so it's can't be a lucky number
+# as well.
+# So we know we have at most one lucky number.
+# Finding it is simple: In each row, find the minimum number, then
+# check whether it is as well the maximum number in its column.
+
+use strict;
+use warnings;
+use List::Util qw(min max);
+
+lucky_numbers([ [ 3,  7,  8], [ 9, 11, 13], [15, 16, 17] ]);
+lucky_numbers([ [ 1, 10,  4,  2], [ 9,  3,  8,  7], [15, 16, 17, 12] ]);
+lucky_numbers([ [7 ,8], [1 ,2] ]);
+lucky_numbers([ [7 ,8], [10 ,2] ]);
+
+sub lucky_numbers {
+   my $matrix = shift;
+   print "Input: [\n";
+   foreach my $row (@$matrix) {
+      print "        [" . join(", ", @$row) . "],\n";
+   }
+   print "       ];\n";
+   my $rows = scalar(@$matrix);
+   my $columns = scalar(@{$matrix->[0]});
+   my $row_min = [];
+   my $column_max = [];
+   foreach my $column (0..$columns-1) {
+      my @column_elements = ();
+      foreach my $row (0..$rows-1) {
+         push @column_elements, $matrix->[$row]->[$column];
+      }
+      push @$column_max, max(@column_elements);
+   }
+   foreach my $i (0..$rows-1) {
+      push @$row_min, min(@{$matrix->[$i]});
+      foreach my $j (0..$columns-1) {
+         my $elem = $matrix->[$i]->[$j];
+         if($elem == $row_min->[$i] && $elem == $column_max->[$j]) {
+            print "Output: $elem\n";
+            return;
+         }
+      }
+   }
+   print "Output: -1\n";
+}
+
+
diff --git a/challenge-251/jeanluc2020/python/ch-1.py b/challenge-251/jeanluc2020/python/ch-1.py
new file mode 100755
index 0000000000..9f0b248134
--- /dev/null
+++ b/challenge-251/jeanluc2020/python/ch-1.py
@@ -0,0 +1,87 @@
+#!/usr/bin/python3
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-251/#TASK1
+#
+# Task 1: Concatenation Value
+# ===========================
+#
+# You are given an array of integers, @ints.
+#
+# Write a script to find the concatenation value of the given array.
+#
+# The concatenation of two numbers is the number formed by concatenating their
+# numerals.
+#
+## For example, the concatenation of 10, 21 is 1021.
+## The concatenation value of @ints is initially equal to 0.
+## Perform this operation until @ints becomes empty:
+##
+## If there exists more than one number in @ints, pick the first element
+## and last element in @ints respectively and add the value of their
+## concatenation to the concatenation value of @ints, then delete the
+## first and last element from @ints.
+##
+## If one element exists, add its value to the concatenation value of
+## @ints, then delete it.
+#
+## Example 1
+##
+## Input: @ints = (6, 12, 25, 1)
+## Output: 1286
+##
+## 1st operation: concatenation of 6 and 1 is 61
+## 2nd operation: concaternation of 12 and 25 is 1225
+##
+## Concatenation Value => 61 + 1225 => 1286
+#
+## Example 2
+##
+## Input: @ints = (10, 7, 31, 5, 2, 2)
+## Output: 489
+##
+## 1st operation: concatenation of 10 and 2 is 102
+## 2nd operation: concatenation of 7 and 2 is 72
+## 3rd operation: concatenation of 31 and 5 is 315
+##
+## Concatenation Value => 102 + 72 + 315 => 489
+#
+## Example 3
+##
+## Input: @ints = (1, 2, 10)
+## Output: 112
+##
+## 1st operation: concatenation of 1 and 10 is 110
+## 2nd operation: only element left is 2
+##
+## Concatenation Value => 110 + 2 => 112
+#
+############################################################
+##
+## discussion
+##
+############################################################
+#
+# Starting with a sum of 0, we call a function that just concatenates
+# the first and last elements of @ints and adds that number to the
+# current sum, then we call the function recursively with the new
+# current sum and the remainder of the array. Of course handle the
+# case where there is only one element in the array by returning the
+# current sum + the last element, and the case of an empty array by
+# returning the current sum.
+
+def concatenation_value_(current: int, ints: list) -> int:
+    if len(ints) == 0:
+        return current
+    if len(ints) == 1:
+        return current + ints[0]
+    value = str(ints[0]) + str(ints[-1])
+    return concatenation_value_(current + int(value), ints[1:-1])
+
+def concatenation_value(ints: list) -> None:
+    print("Input: (", ", ".join([str(x) for x in ints]), ")")
+    result = concatenation_value_(0, ints)
+    print(f"Output: {result}")
+
+concatenation_value([6, 12, 25, 1])
+concatenation_value([10, 7, 31, 5, 2, 2])
+concatenation_value([1, 2, 10])
+
diff --git a/challenge-251/jeanluc2020/python/ch-2.py b/challenge-251/jeanluc2020/python/ch-2.py
new file mode 100755
index 0000000000..33dd88684d
--- /dev/null
+++ b/challenge-251/jeanluc2020/python/ch-2.py
@@ -0,0 +1,82 @@
+#!/usr/bin/perl
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-251/#TASK2
+#
+# Task 2: Lucky Numbers
+# =====================
+#
+# You are given a m x n matrix of distinct numbers.
+#
+# Write a script to return the lucky number, if there is one, or -1 if not.
+#
+## A lucky number is an element of the matrix such that it is
+## the minimum element in its row and maximum in its column.
+#
+## Example 1
+##
+## Input: $matrix = [ [ 3,  7,  8],
+##                    [ 9, 11, 13],
+##                    [15, 16, 17] ];
+## Output: 15
+##
+## 15 is the only lucky number since it is the minimum in its row
+## and the maximum in its column.
+#
+## Example 2
+##
+## Input: $matrix = [ [ 1, 10,  4,  2],
+##                    [ 9,  3,  8,  7],
+##                    [15, 16, 17, 12] ];
+## Output: 12
+#
+## Example 3
+##
+## Input: $matrix = [ [7 ,8],
+##                    [1 ,2] ];
+## Output: 7
+#
+############################################################
+##
+## discussion
+##
+############################################################
+#
+# For a lucky number, we know:
+# Since the minimum in a row is at the same time the maximum in
+# a column, there is no number bigger in that column, so in all
+# other rows, there is a number that is smaller than the current
+# number, so the minimum in that other row has to be smaller or
+# equal to this number; being smaller, it can't be bigger than any
+# of the numbers in the original row, so it's can't be a lucky number
+# as well.
+# So we know we have at most one lucky number.
+# Finding it is simple: In each row, find the minimum number, then
+# check whether it is as well the maximum number in its column.
+
+def lucky_numbers(matrix: list) -> None:
+    print("Input: [");
+    for row in matrix:
+        print("        [", ", ".join([str(x) for x in row]), "],")
+    print("       ];")
+    rows = len(matrix)
+    columns = len(matrix[0])
+    row_min = []
+    column_max = []
+    for column in range(columns):
+        column_elements = []
+        for row in range(rows):
+            column_elements.append(matrix[row][column])
+        column_max.append(max(column_elements))
+    for i in range(rows):
+        row_min.append(min(matrix[i]))
+        for j in range(columns):
+            elem = matrix[i][j]
+            if elem == row_min[i] and elem == column_max[j]:
+                print(f"Output: {elem}")
+                return
+    print("Output: -1")
+
+lucky_numbers([ [ 3,  7,  8], [ 9, 11, 13], [15, 16, 17] ])
+lucky_numbers([ [ 1, 10,  4,  2], [ 9,  3,  8,  7], [15, 16, 17, 12] ])
+lucky_numbers([ [7 ,8], [1 ,2] ])
+lucky_numbers([ [7 ,8], [10 ,2] ])
+
-- 
cgit 


From 87a1cd6110b045d9095085a87d46515abd8a2da4 Mon Sep 17 00:00:00 2001
From: Michael Manring <michael@manring>
Date: Mon, 8 Jan 2024 22:58:40 +1100
Subject: pwc251 solution in go

---
 challenge-251/pokgopun/go/ch-1.go | 119 ++++++++++++++++++++++++++++++++++++++
 challenge-251/pokgopun/go/ch-2.go | 110 +++++++++++++++++++++++++++++++++++
 2 files changed, 229 insertions(+)
 create mode 100644 challenge-251/pokgopun/go/ch-1.go
 create mode 100644 challenge-251/pokgopun/go/ch-2.go

diff --git a/challenge-251/pokgopun/go/ch-1.go b/challenge-251/pokgopun/go/ch-1.go
new file mode 100644
index 0000000000..f74e5e089d
--- /dev/null
+++ b/challenge-251/pokgopun/go/ch-1.go
@@ -0,0 +1,119 @@
+//# https://theweeklychallenge.org/blog/perl-weekly-challenge-251/
+/*#
+
+Task 1: Concatenation Value
+
+Submitted by: [52]Mohammad S Anwar
+     __________________________________________________________________
+
+   You are given an array of integers, @ints.
+
+   Write a script to find the concatenation value of the given array.
+
+   The concatenation of two numbers is the number formed by concatenating
+   their numerals.
+For example, the concatenation of 10, 21 is 1021.
+The concatenation value of @ints is initially equal to 0.
+Perform this operation until @ints becomes empty:
+
+If there exists more than one number in @ints, pick the first element
+and last element in @ints respectively and add the value of their
+concatenation to the concatenation value of @ints, then delete the
+first and last element from @ints.
+
+If one element exists, add its value to the concatenation value of
+@ints, then delete it.
+
+Example 1
+
+Input: @ints = (6, 12, 25, 1)
+Output: 1286
+
+1st operation: concatenation of 6 and 1 is 61
+2nd operation: concaternation of 12 and 25 is 1225
+
+Concatenation Value => 61 + 1225 => 1286
+
+Example 2
+
+Input: @ints = (10, 7, 31, 5, 2, 2)
+Output: 489
+
+1st operation: concatenation of 10 and 2 is 102
+2nd operation: concatenation of 7 and 2 is 72
+3rd operation: concatenation of 31 and 5 is 315
+
+Concatenation Value => 102 + 72 + 315 => 489
+
+Example 3
+
+Input: @ints = (1, 2, 10)
+Output: 112
+
+1st operation: concatenation of 1 and 10 is 110
+2nd operation: only element left is 2
+
+Concatenation Value => 110 + 2 => 112
+
+Task 2: Lucky Numbers
+#*/
+//# solution by pokgopun@gmail.com
+
+package main
+
+import (
+	"io"
+	"os"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+type ints []int
+
+func (is ints) concat() int {
+	l := len(is)
+	switch l {
+	case 0:
+		return 0
+	case 1:
+		return is[0]
+	default:
+		c := is[0]
+		for i := 1; i < l; i++ {
+			lim := is[i]
+			for lim > 0 {
+				lim /= 10
+				c *= 10
+			}
+			c += is[i]
+		}
+		return c
+	}
+}
+
+func (is ints) concatenation() int {
+	l := len(is)
+	lim := l / 2
+	c := 0
+	for i := 0; i < lim; i++ {
+		//fmt.Println(ints{is[i], is[l-1-i]}.concat())
+		c += ints{is[i], is[l-1-i]}.concat()
+	}
+	if l%2 == 1 {
+		c += is[lim]
+	}
+	return c
+}
+
+func main() {
+	for _, data := range []struct {
+		input  ints
+		output int
+	}{
+		{ints{6, 12, 25, 1}, 1286},
+		{ints{10, 7, 31, 5, 2, 2}, 489},
+		{ints{1, 2, 10}, 112},
+	} {
+		io.WriteString(os.Stdout, cmp.Diff(data.input.concatenation(), data.output)) // display nothing if ok, otherwise show the difference
+	}
+}
diff --git a/challenge-251/pokgopun/go/ch-2.go b/challenge-251/pokgopun/go/ch-2.go
new file mode 100644
index 0000000000..f4dfec84ea
--- /dev/null
+++ b/challenge-251/pokgopun/go/ch-2.go
@@ -0,0 +1,110 @@
+//# https://theweeklychallenge.org/blog/perl-weekly-challenge-251/
+/*#
+
+Task 2: Lucky Numbers
+
+Submitted by: [53]Mohammad S Anwar
+     __________________________________________________________________
+
+   You are given a m x n matrix of distinct numbers.
+
+   Write a script to return the lucky number, if there is one, or -1 if
+   not.
+A lucky number is an element of the matrix such that it is
+the minimum element in its row and maximum in its column.
+
+Example 1
+
+Input: $matrix = [ [ 3,  7,  8],
+                   [ 9, 11, 13],
+                   [15, 16, 17] ];
+Output: 15
+
+15 is the only lucky number since it is the minimum in its row
+and the maximum in its column.
+
+Example 2
+
+Input: $matrix = [ [ 1, 10,  4,  2],
+                   [ 9,  3,  8,  7],
+                   [15, 16, 17, 12] ];
+Output: 12
+
+Example 3
+
+Input: $matrix = [ [7 ,8],
+                   [1 ,2] ];
+Output: 7
+     __________________________________________________________________
+
+   Last date to submit the solution 23:59 (UK Time) Sunday 14th January
+   2024.
+     __________________________________________________________________
+
+SO WHAT DO YOU THINK ?
+#*/
+//# solution by pokgopun@gmail.com
+
+package main
+
+import (
+	"io"
+	"os"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+type row []int
+
+func (rw row) minIdx() int {
+	l := len(rw)
+	switch l {
+	case 0:
+		return -1
+	case 1:
+		return 0
+	default:
+		j := 0
+		for i, v := range rw[1:] {
+			if rw[j] > v {
+				j = i + 1
+			}
+		}
+		return j
+	}
+}
+
+type matrix []row
+
+func (mt matrix) lucky() int {
+	l := len(mt)
+	switch l {
+	case 1:
+		return mt[0][mt[0].minIdx()]
+	default:
+		for _, rw := range mt {
+			i := rw.minIdx()
+			mx := mt[0][i]
+			for _, v := range mt[1:] {
+				mx = max(mx, v[i])
+			}
+			if mx == rw[i] {
+				return mx
+			}
+		}
+	}
+	return -1
+}
+
+func main() {
+	for _, data := range []struct {
+		input  matrix
+		output int
+	}{
+		{matrix{row{3, 7, 8}, row{9, 11, 13}, row{15, 16, 17}}, 15},
+		{matrix{row{1, 10, 4, 2}, row{9, 3, 8, 7}, row{15, 16, 17, 12}}, 12},
+		{matrix{row{7, 8}, row{1, 2}}, 7},
+	} {
+		io.WriteString(os.Stdout, cmp.Diff(data.input.lucky(), data.output)) // display nothing if ok, otherwise show the difference
+	}
+}
-- 
cgit 


From 21209f0c085ea3916f95ba72f0f867dcae1343a7 Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 8 Jan 2024 13:54:47 +0000
Subject: Challenge 251 Solutions (Raku)

---
 challenge-251/mark-anderson/raku/ch-1.raku | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/challenge-251/mark-anderson/raku/ch-1.raku b/challenge-251/mark-anderson/raku/ch-1.raku
index 6b938ecd27..59d0543404 100644
--- a/challenge-251/mark-anderson/raku/ch-1.raku
+++ b/challenge-251/mark-anderson/raku/ch-1.raku
@@ -7,5 +7,5 @@ is concat-val([1,2,10]),        112;
 
 sub concat-val(@a)
 {
-    [+] map { @a.shift ~ (@a.pop || Empty) }, ^(@a / 2)
+    sum do while @a { @a.shift ~ (@a.pop || Empty) } 
 }
-- 
cgit 


From 383ceb7778a970f4cd188c5f0bf27f1ea685b21a Mon Sep 17 00:00:00 2001
From: Peter Campbell Smith <pj.campbell.smith@gmail.com>
Date: Mon, 8 Jan 2024 14:57:52 +0000
Subject: Week 251 ...

---
 challenge-251/peter-campbell-smith/blog.txt     |   1 +
 challenge-251/peter-campbell-smith/perl/ch-1.pl |  38 ++++++++
 challenge-251/peter-campbell-smith/perl/ch-2.pl | 117 ++++++++++++++++++++++++
 3 files changed, 156 insertions(+)
 create mode 100644 challenge-251/peter-campbell-smith/blog.txt
 create mode 100755 challenge-251/peter-campbell-smith/perl/ch-1.pl
 create mode 100755 challenge-251/peter-campbell-smith/perl/ch-2.pl

diff --git a/challenge-251/peter-campbell-smith/blog.txt b/challenge-251/peter-campbell-smith/blog.txt
new file mode 100644
index 0000000000..4dce7e403d
--- /dev/null
+++ b/challenge-251/peter-campbell-smith/blog.txt
@@ -0,0 +1 @@
+http://ccgi.campbellsmiths.force9.co.uk/challenge/251
diff --git a/challenge-251/peter-campbell-smith/perl/ch-1.pl b/challenge-251/peter-campbell-smith/perl/ch-1.pl
new file mode 100755
index 0000000000..478f3c5960
--- /dev/null
+++ b/challenge-251/peter-campbell-smith/perl/ch-1.pl
@@ -0,0 +1,38 @@
+#!/usr/bin/perl
+
+use v5.16;    # The Weekly Challenge - 2024-01-08
+use utf8;     # Week 251 task 1 - Concatenation value
+use strict;   # Peter Campbell Smith
+use warnings; # Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge
+
+binmode STDOUT, ':utf8';
+my ($j, @ints);
+
+concatenation_value(6, 12, 25, 1);
+concatenation_value(10, 7, 31, 5, 2, 2);
+concatenation_value(1, 2, 10);
+
+for $j (0 .. 99) {
+	push(@ints, int(rand(99)));
+}
+concatenation_value(@ints);
+
+sub concatenation_value {
+	
+	my(@ints, $sum, $j, $k);
+	
+	# initialise
+	@ints = @_;
+	$sum = 0;
+	
+	# iterate from both ends
+	for $j (0 .. @ints) {
+		$k = @ints - $j - 1;
+		last if $k < $j;
+		$sum += ($k == $j ? $ints[$j] : $ints[$j] . $ints[$k]);
+	}
+	
+	# show result
+	say qq[\nInput:  (] . join(', ', @ints) . ')';
+	say qq[Output: $sum];
+}
diff --git a/challenge-251/peter-campbell-smith/perl/ch-2.pl b/challenge-251/peter-campbell-smith/perl/ch-2.pl
new file mode 100755
index 0000000000..d8d37a3015
--- /dev/null
+++ b/challenge-251/peter-campbell-smith/perl/ch-2.pl
@@ -0,0 +1,117 @@
+#!/usr/bin/perl
+
+use v5.16;    # The Weekly Challenge - 2024-01-08
+use utf8;     # Week 251 task 2 - Lucky numbers
+use strict;   # Peter Campbell Smith
+use warnings; # Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge
+
+binmode STDOUT, ':utf8';
+
+lucky_numbers([[ 3,  7,  8],
+               [ 9, 11, 13],
+               [15, 16, 17]]);
+			   
+lucky_numbers([[ 1, 10,  4,  2],
+               [ 9,  3,  8,  7],
+               [15, 16, 17, 12]]);
+			   
+lucky_numbers([[7, 8],
+               [1, 2]]);
+			   
+lucky_numbers([[1, 2, 3],
+			   [2, 1, 4],
+			   [3, 4, 1]]);
+			   
+lucky_numbers([[7, 4, 4, 7],
+			   [6, 5, 5, 6],
+			   [6, 5, 5, 6],
+			   [7, 4, 4, 7]]);
+			    
+			   			
+sub lucky_numbers {
+	
+	my ($r, $c, @lucky);
+	our ($m, @mins, @maxs);
+	@mins = @maxs = ();
+	
+	$m = shift;
+	
+	# loop over elements of matrix
+	for $r (0 .. @$m - 1) {
+		for $c (0 .. @{$m->[0]} - 1) {
+			
+			# save value if element is lucky
+			push(@lucky, $m->[$r]->[$c]) if (min_in_row($r, $c) and max_in_col($r, $c));
+		}
+	}
+	say format_matrix(qq{\nInput: \@matrix = }, $m);
+	say qq[Output: ] . (@lucky > 0 ? join(', ', @lucky) : -1);
+
+	sub min_in_row {
+		
+		my ($r, $c, $cx, $min_value);
+		
+		# return true/false if element $m($r, $c) is the minimum in its row
+		($r, $c) = @_;
+		
+		# return saved value if we've been here before
+		return ($mins[$r] == $m->[$r]->[$c] ? 1 : 0) if defined $mins[$r];
+		
+		# or determine and save it if not
+		$min_value = 99999;
+		for $cx (0 .. @{$m->[0]} - 1) {
+			$min_value = $m->[$r]->[$cx] if $m->[$r]->[$cx] < $min_value;
+		}
+		$mins[$r] = $min_value;
+		return $m->[$r]->[$c] == $min_value;
+	}
+	
+	sub max_in_col {
+		
+		my ($r, $c, $rx, $max_value);
+		
+		# return true/false if element $m($r, $c) is the maximum in its column
+		($r, $c) = @_;
+
+		# return saved value if we've been here before
+		return ($maxs[$c] == $m->[$r]->[$c] ? 1 : 0) if defined $maxs[$c];
+		
+		# or determine and save it if not
+		$max_value = -99999;
+		for $rx (0 .. @$m - 1) {
+			$max_value = $m->[$rx]->[$c] if $m->[$rx]->[$c] > $max_value;
+		}
+		$maxs[$c] = $max_value;
+		return $m->[$r]->[$c] == $max_value;
+	}
+}
+
+sub format_matrix {
+	
+	# format the output
+	my ($w, $m, $r, $c, $prefix, $width, $rubric, $spaces, $line);
+	
+	($rubric, $m) = @_;
+	$spaces = length($rubric);
+	
+	# find maximum width of element as printed by Perl
+	$w = 0;
+	for $r (0 .. @$m - 1) {
+		for $c (0. .. @{$m->[0]} - 1) {
+			$width = length($m->[$r]->[$c]);
+			$w = $width if $width > $w;
+		}
+	}
+	
+	# construct and output each row of matrix
+	for $r (0 .. @$m - 1) {
+		$line = $rubric . '[';
+		for $c (0 .. @{$m->[0]} - 1) {
+			$line .= sprintf("%${w}d", $m->[$r]->[$c]) . ', ';
+		}
+		$line =~ s|, $|]|;
+		print $line;
+		say '' unless $r == @$m - 1;
+		$rubric = (' ' x ($spaces - 1));
+	}
+}
-- 
cgit 


From 9193caa0085c4e69bdec566035803303ca1ad328 Mon Sep 17 00:00:00 2001
From: Niels van Dijke <perlboy@cpan.org>
Date: Mon, 8 Jan 2024 15:12:17 +0000
Subject: w251 - Task 1 & 2

---
 challenge-251/perlboy1967/perl/ch1.pl | 41 ++++++++++++++++++++++++++++++
 challenge-251/perlboy1967/perl/ch2.pl | 48 +++++++++++++++++++++++++++++++++++
 2 files changed, 89 insertions(+)
 create mode 100755 challenge-251/perlboy1967/perl/ch1.pl
 create mode 100755 challenge-251/perlboy1967/perl/ch2.pl

diff --git a/challenge-251/perlboy1967/perl/ch1.pl b/challenge-251/perlboy1967/perl/ch1.pl
new file mode 100755
index 0000000000..57f97135fc
--- /dev/null
+++ b/challenge-251/perlboy1967/perl/ch1.pl
@@ -0,0 +1,41 @@
+#!/bin/perl
+
+=pod
+
+The Weekly Challenge - 251
+- https://theweeklychallenge.org/blog/perl-weekly-challenge-251
+
+Author: Niels 'PerlBoy' van Dijke
+
+Task 1: Concatenation Value
+Submitted by: Mohammad S Anwar
+
+You are given an array of integers, @ints.
+
+Write a script to find the concatenation value of the given array.
+
+The concatenation of two numbers is the number formed by concatenating
+their numerals.
+
+=cut
+
+use v5.32;
+use feature qw(signatures);
+use common::sense;
+
+use Test2::V0;
+
+use List::Util qw(sum0);
+
+sub concatenationValue (@ints) {
+  # splice in an extra 0 if the list has odd number of elements
+  splice(@ints,$#ints/2-1,1,$ints[$#ints/2-1],0) if ($#ints % 2 == 0);
+  my $i = 0;
+  sum0 map { "$ints[$_]$ints[--$i]" } 0 .. $#ints/2;
+}
+
+is(concatenationValue(6,12,25,1),1286);
+is(concatenationValue(10,7,31,5,2,2),489);
+is(concatenationValue(1,2,10),112);
+
+done_testing;
diff --git a/challenge-251/perlboy1967/perl/ch2.pl b/challenge-251/perlboy1967/perl/ch2.pl
new file mode 100755
index 0000000000..60cd0517ed
--- /dev/null
+++ b/challenge-251/perlboy1967/perl/ch2.pl
@@ -0,0 +1,48 @@
+#!/bin/perl
+
+=pod
+
+The Weekly Challenge - 251
+- https://theweeklychallenge.org/blog/perl-weekly-challenge-251
+
+Author: Niels 'PerlBoy' van Dijke
+
+Task 2: Lucky Numbers
+Submitted by: Mohammad S Anwar
+
+You are given a m x n matrix of distinct numbers.
+
+Write a script to return the lucky number, if there is one, or -1 if not.
+
+A lucky number is an element of the matrix such that it is
+the minimum element in its row and maximum in its column.
+
+=cut
+
+use v5.32;
+use feature qw(signatures);
+use common::sense;
+
+use Test2::V0;
+
+use List::Util qw(min max);
+use List::MoreUtils qw(duplicates);
+
+sub luckyNumber ($ar) {
+  my @min = map { min @{$$ar[$_]} } 0 .. $#$ar;
+  my @max = map { my $c = $_; 
+                  max map { $$ar[$_][$c] } 0 .. $#$ar 
+                } 0 .. $#{$ar->[0]};
+  (duplicates @min,@max)[0];
+}
+
+is(luckyNumber([ [ 3,  7,  8],
+                 [ 9, 11, 13],
+                 [15, 16, 17] ]),15);
+is(luckyNumber([ [ 1, 10,  4,  2],
+                 [ 9,  3,  8,  7],
+                 [15, 16, 17, 12] ]),12);
+is(luckyNumber([ [7 ,8],
+                 [1 ,2] ]), 7);
+
+done_testing;
-- 
cgit 


From 598422b9745ea871f161f2dcbfd883380ab706b1 Mon Sep 17 00:00:00 2001
From: Luis Mochan <mochan@fis.unam.mx>
Date: Mon, 8 Jan 2024 09:30:01 -0600
Subject: SOlve PWC251

---
 challenge-251/wlmb/blog.txt     |  1 +
 challenge-251/wlmb/perl/ch-1.pl | 14 ++++++++++++++
 challenge-251/wlmb/perl/ch-2.pl | 20 ++++++++++++++++++++
 3 files changed, 35 insertions(+)
 create mode 100644 challenge-251/wlmb/blog.txt
 create mode 100755 challenge-251/wlmb/perl/ch-1.pl
 create mode 100755 challenge-251/wlmb/perl/ch-2.pl

diff --git a/challenge-251/wlmb/blog.txt b/challenge-251/wlmb/blog.txt
new file mode 100644
index 0000000000..3c2c1d1653
--- /dev/null
+++ b/challenge-251/wlmb/blog.txt
@@ -0,0 +1 @@
+https://wlmb.github.io/2024/01/08/PWC251/
diff --git a/challenge-251/wlmb/perl/ch-1.pl b/challenge-251/wlmb/perl/ch-1.pl
new file mode 100755
index 0000000000..828c183030
--- /dev/null
+++ b/challenge-251/wlmb/perl/ch-1.pl
@@ -0,0 +1,14 @@
+#!/usr/bin/env perl
+# Perl weekly challenge 251
+# Task 1:  Concatenation Value
+#
+# See https://wlmb.github.io/2024/01/08/PWC251/#task-1-concatenation-value
+use v5.36;
+die <<~"FIN" unless @ARGV;
+    Usage: $0 N1 [N2...]
+    to concatenate and add the numbers N_1 . N_k + N_2 . N_{k-1} +...
+    FIN
+my $tot=0;
+my @ints=@ARGV;
+$tot += shift(@ints).(pop(@ints)//"") while(@ints);
+say "@ARGV -> $tot";
diff --git a/challenge-251/wlmb/perl/ch-2.pl b/challenge-251/wlmb/perl/ch-2.pl
new file mode 100755
index 0000000000..d835b0f63a
--- /dev/null
+++ b/challenge-251/wlmb/perl/ch-2.pl
@@ -0,0 +1,20 @@
+#!/usr/bin/env perl
+# Perl weekly challenge 251
+# Task 2:  Lucky Numbers
+#
+# See https://wlmb.github.io/2024/01/08/PWC251/#task-2-lucky-numbers
+use v5.36;
+use PDL;
+die <<~"FIN" unless @ARGV;
+    Usage: $0 A1 [A2...]
+    to find lucky numbers in the arrays A1, A2...
+    The format of the arrays should be "[[a00 a01...],[a10 a11...],...]",
+    to be read by pdl.
+    FIN
+while(@ARGV){
+    my $in=pdl(shift);
+    my $min=$in->minover->dummy(0);
+    my $max=$in->mv(1,0)->maxover->dummy(1);
+    my $result=$in->where(($in==$min)&($in==$max));
+    say "$in -> ", $result->isempty?-1:$result;
+}
-- 
cgit 


From 71232d40036d0663b1fb1f8b84f63823075f0b68 Mon Sep 17 00:00:00 2001
From: Zapwai <zapwai@gmail.com>
Date: Mon, 8 Jan 2024 11:38:16 -0500
Subject: Week 251

---
 challenge-251/zapwai/c/ch-1.c     | 54 +++++++++++++++++++++++++++
 challenge-251/zapwai/c/ch-2.c     | 77 +++++++++++++++++++++++++++++++++++++++
 challenge-251/zapwai/perl/ch-1.pl | 16 ++++++++
 challenge-251/zapwai/perl/ch-2.pl | 30 +++++++++++++++
 challenge-251/zapwai/rust/ch-1.rs | 25 +++++++++++++
 challenge-251/zapwai/rust/ch-2.rs | 57 +++++++++++++++++++++++++++++
 6 files changed, 259 insertions(+)
 create mode 100644 challenge-251/zapwai/c/ch-1.c
 create mode 100644 challenge-251/zapwai/c/ch-2.c
 create mode 100644 challenge-251/zapwai/perl/ch-1.pl
 create mode 100644 challenge-251/zapwai/perl/ch-2.pl
 create mode 100644 challenge-251/zapwai/rust/ch-1.rs
 create mode 100644 challenge-251/zapwai/rust/ch-2.rs

diff --git a/challenge-251/zapwai/c/ch-1.c b/challenge-251/zapwai/c/ch-1.c
new file mode 100644
index 0000000000..81c6bc263a
--- /dev/null
+++ b/challenge-251/zapwai/c/ch-1.c
@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include <stdlib.h>
+void proc(int*, int);
+int main() {
+  int arr0[] = {6, 12, 25, 1};
+  int arr1[] = {10, 7, 31, 5, 2, 2};  
+  int arr2[] = {1,2,10};
+  int L[3] = {sizeof(arr0)/sizeof(int),
+	      sizeof(arr1)/sizeof(int),
+	      sizeof(arr2)/sizeof(int),
+  };
+  printf("\n");
+  proc(arr0, L[0]);
+  printf("\t-=-=-\n");
+  proc(arr1, L[1]);
+  printf("\t-=-=-\n");  
+  proc(arr2, L[2]);    
+  printf("\n");
+}
+
+void proc(int* arr, int L) {
+  int sum = 0;
+  int k = 0;
+  if (L % 2 == 1) {
+    k = L/2;
+    sum += arr[k];
+  } else {
+    k = L/2 - 1;
+  }
+
+  for (int i = 0; i <= k; i++) {
+    int a;
+    if (L % 2 == 1) {
+      if (i == k) {
+	break;
+      }
+      a = arr[k-i-1];
+    } else {
+      a = arr[k-i];
+    }
+    int b = arr[k+1+i];
+    char x[20];
+    sprintf(x, "%d%d", a,b);
+    int X = atoi(x);
+    //    printf("%d\n",X);
+    sum += X;
+  }
+  printf("Input: arr = {");
+  for (int i = 0; i < L - 1; i++) {
+    printf("%d, ",arr[i]);
+  }
+  printf("%d}\n",arr[L-1]);
+  printf("Output: %d\n",sum);
+}
diff --git a/challenge-251/zapwai/c/ch-2.c b/challenge-251/zapwai/c/ch-2.c
new file mode 100644
index 0000000000..f605e9724c
--- /dev/null
+++ b/challenge-251/zapwai/c/ch-2.c
@@ -0,0 +1,77 @@
+#include <stdio.h>
+void proc(int m,int n, int[m][n]);
+
+void ex1() {  
+  const int M = 3;
+  const int N = 3;
+  int a[M][N] = { { 3,  7,  8},
+		  { 9, 11, 13},
+		  {15, 16, 17} };
+  proc(M,N,a);
+} 
+
+void ex2() {  
+  const int M = 3;
+  const int N = 4;
+  int a[M][N] = { { 1, 10, 4, 2},
+		  { 9, 3, 8, 7},
+		  {15, 16, 17, 12} };
+  proc(M,N,a);
+} 
+
+void ex3() {  
+  const int M = 2;
+  const int N = 2;
+  int a[M][N] = { { 7,  8},
+		  {1, 2} };
+  proc(M,N,a);
+} 
+
+int main() {
+  ex1();
+  ex2();
+  ex3();  
+}
+
+void proc(int M, int N, int a[M][N])  {
+  int mins[M];
+  int maxs[N];
+
+  for (int i = 0; i < M; i++) {
+    int min = a[i][0];
+    for (int j = 0; j < N; j++) {
+      int x = a[i][j];
+      (min > x) ? min = x : 0;
+    }
+    mins[i] = min;
+  }
+  
+  for (int j = 0; j < N; j++) {
+    int max = 0;    
+    for (int i = 0; i < M; i++) {
+      int x = a[i][j];
+      (max < x) ? max = x : 0;
+
+    }
+    maxs[j] = max;
+  }
+
+  int ans = -1;
+  for (int i = 0; i < M; i++) {
+    for (int j = 0; j < N; j++) {
+      if (mins[i] == maxs[j]) {
+	ans = mins[i];
+	goto over;
+      }
+    }
+  }
+ over:
+  printf("Input: M = \n\t");
+  for (int i = 0; i < M; i++) {
+    for (int j = 0; j < N; j++) {
+      printf("%02d ", a[i][j]);
+    }
+    printf("\n\t");
+  }
+  printf("\nOutput: %d\n", ans);
+}
diff --git a/challenge-251/zapwai/perl/ch-1.pl b/challenge-251/zapwai/perl/ch-1.pl
new file mode 100644
index 0000000000..17b06a9cb9
--- /dev/null
+++ b/challenge-251/zapwai/perl/ch-1.pl
@@ -0,0 +1,16 @@
+use v5.30;
+my @ints = (6, 12, 25, 1);
+say "Input: \@ints = (" . join(", ", @ints) . ")";
+my $sum = 0;
+do {
+    proc(\@ints);
+} while (@ints);
+say "Output: $sum";
+sub proc {
+    my $r = shift;
+    my $a = shift @$r;
+    my $b;
+    $b = pop @$r if (@$r) ;
+    my $x = $a.$b;
+    $sum += $x;
+}
diff --git a/challenge-251/zapwai/perl/ch-2.pl b/challenge-251/zapwai/perl/ch-2.pl
new file mode 100644
index 0000000000..e7cad53007
--- /dev/null
+++ b/challenge-251/zapwai/perl/ch-2.pl
@@ -0,0 +1,30 @@
+use v5.30;
+use List::Util qw( max min );
+my $matrix = [ [ 3,  7,  8],
+	       [ 9, 11, 13],
+	       [15, 16, 17],
+	   ];
+say "Input: \$matrix = [";
+say "\t[@$_]" foreach (@$matrix);
+say "\t];";
+my $h = @$matrix;
+my $w = scalar @{$$matrix[0]};
+my $luck = -1;
+my @min;
+for my $i (0 .. $h - 1) {
+    push @min, min (@{$$matrix[$i]});
+}
+my @max;
+for my $j (0 .. $w - 1) {
+    my @col = map { $$matrix[$_][$j] } (0 .. $h - 1) ;
+    push @max, max @col;
+}
+loop: for my $val (@min) {
+    for my $val2 (@max) {
+	if ($val == $val2) {
+	    $luck = $val;
+	    last loop;
+	}
+    }
+}
+say "Output: $luck";
diff --git a/challenge-251/zapwai/rust/ch-1.rs b/challenge-251/zapwai/rust/ch-1.rs
new file mode 100644
index 0000000000..64d08e61ee
--- /dev/null
+++ b/challenge-251/zapwai/rust/ch-1.rs
@@ -0,0 +1,25 @@
+fn main() {
+    let ints = vec![6, 12, 25, 1];
+    let ints2 = vec![10, 7, 31, 5, 2, 2];
+    let ints3 = vec![1, 2, 10];
+    proc(ints);
+    proc(ints2);
+    proc(ints3);    
+}
+
+fn proc (mut ints : Vec<i32>) {
+    println!("Input: ints = {:?}", ints);
+    let mut sum = 0;
+    while ints.len() > 1
+    {
+	let a = ints.remove(0);
+	let b = ints.pop().unwrap();
+	let x = format!("{:?}{:?}",a,b);
+	sum += x.parse::<i32>().unwrap();
+	
+    }
+    if ints.len() == 1 {
+	sum += ints[0];
+    }
+    println!("Output: {sum}");
+}
diff --git a/challenge-251/zapwai/rust/ch-2.rs b/challenge-251/zapwai/rust/ch-2.rs
new file mode 100644
index 0000000000..94f1cdd15a
--- /dev/null
+++ b/challenge-251/zapwai/rust/ch-2.rs
@@ -0,0 +1,57 @@
+fn main() {
+    let a = [ [ 3,  7,  8],
+		[ 9, 11, 13],
+		[15, 16, 17] ];
+
+    // let a = [ [ 1, 10,  4,  2],
+    //             [ 9,  3,  8,  7],
+    //             [15, 16, 17, 12] ];
+
+    // let a = [ [7 ,8],
+    // 	       [1 ,2] ];
+
+    let w :usize = a[0].len();
+    let h :usize = a.len();
+    //     proc(w, h, a);
+    // }
+
+    // fn proc(w: usize, h: usize, a: [[i32;3];3]) {
+    let mut mins = Vec::new();
+    let mut maxs = Vec::new();
+    
+    let mut j = 0;
+    while j <= h-1 {
+	mins.push(a[j].iter().min().unwrap());
+	j += 1;
+    }
+    let mut i = 0;
+    while i <= w-1 {
+	let mut max = -1;
+	j = 0;
+	while j <= h-1 {
+	    let x = a[j][i];
+	    if max < x {
+		max = x;
+	    }
+	    j += 1;
+	}
+	maxs.push(max);
+	i += 1;
+    }
+    
+    let mut luck = -1;
+    'outer:    for i in mins {
+	for j in &maxs {
+	    if i == j {
+		luck = *j;
+		break 'outer;
+	    }
+	}
+    }
+    println!("Input: ");
+    for i in 0 .. h {
+
+	println!("\t{:?}", a[i]);
+    }
+    println!("Output: {luck}");
+}
-- 
cgit 


From bac8160bd6d93442b20aef4e8b5d396939b55c42 Mon Sep 17 00:00:00 2001
From: Dave Jacoby <jacoby.david@gmail.com>
Date: Mon, 8 Jan 2024 12:42:39 -0500
Subject: DAJ #251

---
 challenge-251/dave-jacoby/blog.txt     |  1 +
 challenge-251/dave-jacoby/perl/ch-1.pl | 38 ++++++++++++++++++++
 challenge-251/dave-jacoby/perl/ch-2.pl | 63 ++++++++++++++++++++++++++++++++++
 3 files changed, 102 insertions(+)
 create mode 100644 challenge-251/dave-jacoby/blog.txt
 create mode 100644 challenge-251/dave-jacoby/perl/ch-1.pl
 create mode 100644 challenge-251/dave-jacoby/perl/ch-2.pl

diff --git a/challenge-251/dave-jacoby/blog.txt b/challenge-251/dave-jacoby/blog.txt
new file mode 100644
index 0000000000..61c31e441a
--- /dev/null
+++ b/challenge-251/dave-jacoby/blog.txt
@@ -0,0 +1 @@
+https://jacoby.github.io/2024/01/08/do-you-feel-lucky-weekly-challenge-251.html
diff --git a/challenge-251/dave-jacoby/perl/ch-1.pl b/challenge-251/dave-jacoby/perl/ch-1.pl
new file mode 100644
index 0000000000..3d144f59f4
--- /dev/null
+++ b/challenge-251/dave-jacoby/perl/ch-1.pl
@@ -0,0 +1,38 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+use List::Util qw{ sum0 };
+
+my @examples = (
+
+    [ 6,  12, 25, 1 ],
+    [ 10, 7,  31, 5, 2, 2 ],
+    [ 1,  2,  10 ],
+);
+
+for my $example (@examples) {
+    my $input  = join ', ', $example->@*;
+    my $output = kinda_concatenation( $example->@* );
+
+    say <<~"END";
+    Input:  \$ints = ($input)
+    Output: $output
+    END
+}
+
+sub kinda_concatenation (@input) {
+    my @output;
+    while (@input) {
+        if ( scalar @input == 1 ) {
+            push @output, shift @input;
+        }
+        else {
+