From 8b44b0beb72b0c89f7bc0a3c77a70244ec4d79a9 Mon Sep 17 00:00:00 2001
From: Roger Bell_West <roger@firedrake.org>
Date: Wed, 24 May 2023 23:01:11 +0100
Subject: RogerBW solutions for challenge no. 218

---
 challenge-218/roger-bell-west/javascript/ch-1.js |  52 +++++++
 challenge-218/roger-bell-west/javascript/ch-2.js |  53 +++++++
 challenge-218/roger-bell-west/kotlin/ch-1.kt     |  50 +++++++
 challenge-218/roger-bell-west/kotlin/ch-2.kt     |  56 ++++++++
 challenge-218/roger-bell-west/lua/ch-1.lua       |  52 +++++++
 challenge-218/roger-bell-west/lua/ch-2.lua       |  53 +++++++
 challenge-218/roger-bell-west/perl/ch-1.pl       |  35 +++++
 challenge-218/roger-bell-west/perl/ch-2.pl       |  46 ++++++
 challenge-218/roger-bell-west/postscript/ch-1.ps | 172 +++++++++++++++++++++++
 challenge-218/roger-bell-west/postscript/ch-2.ps |  84 +++++++++++
 challenge-218/roger-bell-west/python/ch-1.py     |  35 +++++
 challenge-218/roger-bell-west/python/ch-2.py     |  38 +++++
 challenge-218/roger-bell-west/raku/ch-1.p6       |  31 ++++
 challenge-218/roger-bell-west/raku/ch-2.p6       |  45 ++++++
 challenge-218/roger-bell-west/ruby/ch-1.rb       |  44 ++++++
 challenge-218/roger-bell-west/ruby/ch-2.rb       |  52 +++++++
 challenge-218/roger-bell-west/rust/ch-1.rs       |  44 ++++++
 challenge-218/roger-bell-west/rust/ch-2.rs       |  52 +++++++
 challenge-218/roger-bell-west/tests.yaml         |  49 +++++++
 19 files changed, 1043 insertions(+)
 create mode 100755 challenge-218/roger-bell-west/javascript/ch-1.js
 create mode 100755 challenge-218/roger-bell-west/javascript/ch-2.js
 create mode 100644 challenge-218/roger-bell-west/kotlin/ch-1.kt
 create mode 100644 challenge-218/roger-bell-west/kotlin/ch-2.kt
 create mode 100755 challenge-218/roger-bell-west/lua/ch-1.lua
 create mode 100755 challenge-218/roger-bell-west/lua/ch-2.lua
 create mode 100755 challenge-218/roger-bell-west/perl/ch-1.pl
 create mode 100755 challenge-218/roger-bell-west/perl/ch-2.pl
 create mode 100644 challenge-218/roger-bell-west/postscript/ch-1.ps
 create mode 100644 challenge-218/roger-bell-west/postscript/ch-2.ps
 create mode 100755 challenge-218/roger-bell-west/python/ch-1.py
 create mode 100755 challenge-218/roger-bell-west/python/ch-2.py
 create mode 100755 challenge-218/roger-bell-west/raku/ch-1.p6
 create mode 100755 challenge-218/roger-bell-west/raku/ch-2.p6
 create mode 100755 challenge-218/roger-bell-west/ruby/ch-1.rb
 create mode 100755 challenge-218/roger-bell-west/ruby/ch-2.rb
 create mode 100755 challenge-218/roger-bell-west/rust/ch-1.rs
 create mode 100755 challenge-218/roger-bell-west/rust/ch-2.rs
 create mode 100644 challenge-218/roger-bell-west/tests.yaml

diff --git a/challenge-218/roger-bell-west/javascript/ch-1.js b/challenge-218/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..1208ea6708
--- /dev/null
+++ b/challenge-218/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,52 @@
+#! /usr/bin/node
+
+function maximumproduct(lst) {
+    let l = lst;
+    l.sort(function(a,b) {
+        return a-b;
+    });
+    const b = l.length;
+    let t = [];
+    for (let i = 0; i <= 3; i++) {
+        let p = 1;
+        if (i > 0) {
+            for (let j = 0; j < i; j++) {
+                p *= l[j];
+            }
+        }
+        if (i < 3) {
+            for (let j = b - 3 + i; j < b; j++) {
+                p *= l[j];
+            }
+        }
+        t.push(p);
+    }
+    return Math.max(...t);
+}
+
+"use strict"
+
+if (maximumproduct([3, 1, 2]) == 6) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (maximumproduct([4, 1, 3, 2]) == 24) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (maximumproduct([-1, 0, 1, 3, 1]) == 3) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (maximumproduct([-8, 2, -9, 0, -4, 3]) == 216) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-218/roger-bell-west/javascript/ch-2.js b/challenge-218/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..76dd4f42ea
--- /dev/null
+++ b/challenge-218/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,53 @@
+#! /usr/bin/node
+
+"use strict"
+
+function matrixscore(matrix0) {
+    let matrix = matrix0;
+    for (let i = 0; i < matrix.length; i++) {
+        if (matrix[i][0] == 0) {
+            for (let j = 0; j < matrix[i].length; j++) {
+                matrix[i][j] = 1 - matrix[i][j];
+            }
+        }
+    }
+    const t = Math.floor(matrix.length / 2);
+    for (let i = 1; i < matrix[0].length; i++) {
+        let c = 0;
+        for (let j = 0; j < matrix.length; j++) {
+            if (matrix[j][i] == 0) {
+                c += 1;
+            }
+        }
+        if (c > t) {
+            for (let j= 0; j < matrix.length; j++) {
+                matrix[j][i] = 1 - matrix[j][i];
+            }
+        }
+    }
+    let tot = 0;
+    for (let m of matrix) {
+        let p = 0;
+        for (let n of m) {
+            p *= 2;
+            if (n == 1) {
+                p += 1;
+            }
+        }
+        tot += p;
+    }
+    return tot;
+}
+
+if (matrixscore([[0, 0, 1, 1], [1, 0, 1, 0], [1, 1, 1, 0]]) == 39) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (matrixscore([[0]]) == 1) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-218/roger-bell-west/kotlin/ch-1.kt b/challenge-218/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..7f791f1802
--- /dev/null
+++ b/challenge-218/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,50 @@
+fun maximumproduct(lst: List<Int>): Int {
+    var l = ArrayList(lst)
+    l.sort()
+    val b = l.size
+    var t = ArrayList<Int>()
+    for (i in 0..3) {
+        var p = 1
+        if (i > 0) {
+            for (j in 0 .. i-1) {
+                p *= l[j]
+            }
+        }
+        if (i < 3) {
+            for (j in b - 3 + i .. b-1) {
+                p *= l[j]
+            }
+        }
+        t.add(p)
+    }
+    return t.maxOrNull()!!
+}
+
+fun main() {
+
+    if (maximumproduct(listOf(3, 1, 2)) == 6) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (maximumproduct(listOf(4, 1, 3, 2)) == 24) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (maximumproduct(listOf(-1, 0, 1, 3, 1)) == 3) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (maximumproduct(listOf(-8, 2, -9, 0, -4, 3)) == 216) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-218/roger-bell-west/kotlin/ch-2.kt b/challenge-218/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..0cfcd6d337
--- /dev/null
+++ b/challenge-218/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,56 @@
+fun matrixscore(matrix0: List<List<Int>>): Int {
+    var matrix = ArrayList<ArrayList<Int>>()
+    for (r in matrix0) {
+        matrix.add(ArrayList(r))
+    }
+    for (i in 0 .. matrix.size-1) {
+        if (matrix[i][0] == 0) {
+            for (j in 0 .. matrix[i].size-1) {
+                matrix[i][j] = 1 - matrix[i][j]
+            }
+        }
+    }
+    val t = matrix.size / 2
+    for (i in 1 .. matrix[0].size-1) {
+        var c = 0
+        for (j in 0 .. matrix.size-1) {
+            if (matrix[j][i] == 0) {
+                c += 1
+            }
+        }
+        if (c > t) {
+            for (j in 0 .. matrix.size-1) {
+                matrix[j][i] = 1 - matrix[j][i]
+            }
+        }
+    }
+    var tot = 0
+    for (m in matrix) {
+        var p = 0
+        for (n in m) {
+            p *= 2
+            if (n == 1) {
+                p += 1
+            }
+        }
+        tot += p
+    }
+    return tot
+}
+
+fun main() {
+
+    if (matrixscore(listOf(listOf(0, 0, 1, 1), listOf(1, 0, 1, 0), listOf(1, 1, 1, 0))) == 39) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (matrixscore(listOf(listOf(0))) == 1) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-218/roger-bell-west/lua/ch-1.lua b/challenge-218/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..fd4065b56f
--- /dev/null
+++ b/challenge-218/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,52 @@
+#! /usr/bin/lua
+
+function maximumproduct(lst)
+   local l = lst
+   table.sort(l)
+   local b = #l
+   local t = {}
+   for i = 0, 3 do
+      local p = 1
+      if i > 0 then
+         for j = 1, i do
+            p = p * l[j]
+         end
+      end
+      if i < 3 then
+         for j = b - 2 + i, b do
+            p = p * l[j]
+         end
+      end
+      table.insert(t, p)
+   end
+   return math.max(table.unpack(t))
+end
+
+if maximumproduct({3, 1, 2}) == 6 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if maximumproduct({4, 1, 3, 2}) == 24 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if maximumproduct({-1, 0, 1, 3, 1}) == 3 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if maximumproduct({-8, 2, -9, 0, -4, 3}) == 216 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-218/roger-bell-west/lua/ch-2.lua b/challenge-218/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..2981524741
--- /dev/null
+++ b/challenge-218/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,53 @@
+#! /usr/bin/lua
+
+function matrixscore(matrix0)
+   local matrix = matrix0
+   for i = 1, #matrix do
+      if matrix[i][1] == 0 then
+         for j = 1, #(matrix[i]) do
+            matrix[i][j] = 1 - matrix[i][j]
+         end
+      end
+   end
+   local t = #matrix // 2
+   for i = 2, #(matrix[1]) do
+      local c = 0
+      for j = 1, #matrix do
+         if matrix[j][i] == 0 then
+            c = c + 1
+         end
+      end
+      if c > t then
+         for j = 1, #matrix do
+            matrix[j][i] = 1 - matrix[j][i]
+         end
+      end
+   end
+   local tot = 0
+   for _a, m in ipairs(matrix) do
+      local p = 0
+      for _b, n in ipairs(m) do
+         p = p * 2
+         if n == 1 then
+            p = p + 1
+         end
+      end
+      tot = tot + p
+   end
+   return tot
+end
+
+if matrixscore({{0, 0, 1, 1}, {1, 0, 1, 0}, {1, 1, 1, 0}}) == 39 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if matrixscore({{0}}) == 1 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-218/roger-bell-west/perl/ch-1.pl b/challenge-218/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..4219de5b6a
--- /dev/null
+++ b/challenge-218/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,35 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 4;
+
+use List::Util qw(max);
+
+is(maximumproduct([3, 1, 2]), 6, 'example 1');
+is(maximumproduct([4, 1, 3, 2]), 24, 'example 2');
+is(maximumproduct([-1, 0, 1, 3, 1]), 3, 'example 3');
+is(maximumproduct([-8, 2, -9, 0, -4, 3]), 216, 'example 4');
+
+sub maximumproduct($lst) {
+  my @l = sort {$a <=> $b} @{$lst};
+  my $b = scalar @l;
+  my @t;
+  foreach my $i (0..3) {
+    my $p = 1;
+    if ($i > 0) {
+      foreach my $j (0..$i-1) {
+        $p *= $l[$j];
+      }
+    }
+    if ($i < 3) {
+      foreach my $j ($b-3+$i..$b-1) {
+        $p *= $l[$j];
+      }
+    }
+    push @t, $p;
+  }
+  return max(@t);
+}
diff --git a/challenge-218/roger-bell-west/perl/ch-2.pl b/challenge-218/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..cc7474f36a
--- /dev/null
+++ b/challenge-218/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,46 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 2;
+
+is(matrixscore([[0, 0, 1, 1], [1, 0, 1, 0], [1, 1, 1, 0]]), 39, 'example 1');
+is(matrixscore([[0]]), 1, 'example 2');
+
+sub matrixscore($matrix) {
+  foreach my $i (0..$#{$matrix}) {
+    if ($matrix->[$i][0] == 0) {
+      foreach my $j (0..$#{$matrix->[0]}) {
+        $matrix->[$i][$j] = 1 - $matrix->[$i][$j];
+      }
+    }
+  }
+  my $t = int(scalar @{$matrix} / 2);
+  foreach my $i (1..$#{$matrix->[0]}) {
+    my $c = 0;
+    foreach my $j (0..$#{$matrix}) {
+      if ($matrix->[$j][$i] == 0) {
+        $c++;
+      }
+    }
+    if ($c > $t) {
+      foreach my $j (0..$#{$matrix}) {
+        $matrix->[$j][$i] = 1 - $matrix->[$j][$i];
+      }
+    }
+  }
+  my $tot = 0;
+  foreach my $m (@{$matrix}) {
+    my $p = 0;
+    foreach my $n (@{$m}) {
+      $p *= 2;
+      if ($n == 1) {
+        $p++;
+      }
+    }
+    $tot += $p;
+  }
+  return $tot;
+}
diff --git a/challenge-218/roger-bell-west/postscript/ch-1.ps b/challenge-218/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..6730a05b8b
--- /dev/null
+++ b/challenge-218/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,172 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/quicksort.cmp {
+    2 copy
+    lt {
+        pop pop -1
+    } {
+        gt {
+            1
+        } {
+            0
+        } ifelse
+    } ifelse
+} bind def
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+/reduce { % array proc -> value
+    2 dict begin
+    /p exch def
+    /a exch def
+    a 0 get
+    1 1 a length 1 sub {
+        a exch get
+        p
+    } for
+    end
+} bind def
+
+/quicksort.partition {
+    3 dict begin
+    /pivot arr hi lo add 2 idiv get def
+    /i lo 1 sub def
+    /j hi 1 add def
+    {
+        {
+            /i i 1 add def
+            arr i get pivot cmp 0 ge {
+                exit
+            } if
+        } loop
+        {
+            /j j 1 sub def
+            arr j get pivot cmp 0 le {
+                exit
+            } if
+        } loop
+        i j ge {
+            j
+            exit
+        } if
+        i j quicksort.swap
+    } loop
+    end
+} bind def
+
+/quicksort {
+    { quicksort.cmp } quicksort.with_comparator
+} bind def
+
+/test.end {
+    ( ) print
+    test.count 0 gt {
+        (Passed ) print
+        test.pass (...) cvs print
+        (/) print
+        test.count (...) cvs print
+        ( \() print
+        test.pass 100 mul test.count idiv (...) cvs print
+        (%\)) print
+        (\r\n) print
+    } if
+} bind def
+
+/quicksort.with_comparator { % [ a c b ] { comparator } -> [ a b c ]
+    2 dict begin
+    /cmp exch def
+    /arr exch def
+    arr length 0 gt {
+        0 arr length 1 sub quicksort.main
+    } if
+    arr
+    end
+} bind def
+
+/quicksort.main { % lo hi -> (null)
+    3 dict begin
+    /hi exch def
+    /lo exch def
+    /xit false def
+    lo 0 lt {
+        /xit true def
+    } if
+    hi 0 lt {
+        /xit true def
+    } if
+    lo hi ge {
+        /xit true def
+    } if
+    xit not {
+        /p quicksort.partition def
+        lo p quicksort.main
+        p 1 add hi quicksort.main
+    } if
+    end
+} bind def
+
+/quicksort.swap {
+    2 dict begin
+    /bi exch def
+    /ai exch def
+    arr ai get
+    arr bi get
+    arr exch ai exch put
+    arr exch bi exch put
+    end
+} bind def
+
+/test {
+    /test.count test.count 1 add def
+    {
+        /test.pass test.pass 1 add def
+    } {
+        ( ) print
+        test.count (....) cvs print
+        (-fail) print
+    } ifelse
+} bind def
+
+/listmax {
+    { max } reduce
+} bind def
+
+
+% end included library code
+
+/maximumproduct {
+    4 dict begin
+    /l exch quicksort def
+    /b l length def
+    [
+        0 1 3 {
+            /i exch def
+            /p 1 def
+            i 0 gt {
+                0 1 i 1 sub {
+                    l exch get p mul /p exch def
+                } for
+            } if
+            i 3 lt {
+                b 3 sub i add 1 b 1 sub {
+                    l exch get p mul /p exch def
+                } for
+            } if
+            p
+        } for
+    ] listmax
+    end
+} bind def
+
+(maximumproduct) test.start
+[3 1 2] maximumproduct 6 eq test
+[4 1 3 2] maximumproduct 24 eq test
+[-1 0 1 3 1] maximumproduct 3 eq test
+[-8 2 -9 0 -4 3] maximumproduct 216 eq test
+test.end
diff --git a/challenge-218/roger-bell-west/postscript/ch-2.ps b/challenge-218/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..89fede440d
--- /dev/null
+++ b/challenge-218/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,84 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/test {
+    /test.count test.count 1 add def
+    {
+        /test.pass test.pass 1 add def
+    } {
+        ( ) print
+        test.count (....) cvs print
+        (-fail) print
+    } ifelse
+} bind def
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+/test.end {
+    ( ) print
+    test.count 0 gt {
+        (Passed ) print
+        test.pass (...) cvs print
+        (/) print
+        test.count (...) cvs print
+        ( \() print
+        test.pass 100 mul test.count idiv (...) cvs print
+        (%\)) print
+        (\r\n) print
+    } if
+} bind def
+
+
+% end included library code
+
+/matrixscore {
+    4 dict begin
+    /mx exch def
+    0 1 mx length 1 sub {
+        /i exch def
+        mx i get 0 get 0 eq {
+            0 1 mx i get length 1 sub {
+                /j exch def
+                mx i get dup j get 1 exch sub j exch put
+            } for
+        } if
+    } for
+    /t mx length 2 idiv def
+    1 1 mx 0 get length 1 sub {
+        /i exch def
+        0
+        0 1 mx length 1 sub {
+            mx exch get i get 0 eq {
+                1 add
+            } if
+        } for
+        t gt {
+            0 1 mx length 1 sub {
+                /j exch def
+                mx j get dup i get 1 exch sub i exch put
+            } for
+        } if
+    } for
+    0
+    mx {
+        0 exch
+        {
+            exch 2 mul exch
+            1 eq {
+                1 add
+            } if
+        } forall
+        add
+    } forall
+    end
+} bind def
+
+(matrixscore) test.start
+[[0 0 1 1] [1 0 1 0] [1 1 1 0]] matrixscore 39 eq test
+[[0]] matrixscore 1 eq test
+test.end
diff --git a/challenge-218/roger-bell-west/python/ch-1.py b/challenge-218/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..e148c40816
--- /dev/null
+++ b/challenge-218/roger-bell-west/python/ch-1.py
@@ -0,0 +1,35 @@
+#! /usr/bin/python3
+
+def maximumproduct(lst):
+  l = lst
+  l.sort()
+  b = len(l)
+  t = []
+  for i in range(4):
+    p = 1
+    if i > 0:
+      for j in range(i):
+        p *= l[j]
+    if i < 3:
+      for j in range(b - 3 + i, b):
+        p *= l[j]
+    t.append(p)
+  return max(t)
+
+import unittest
+
+class TestMaximumproduct(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(maximumproduct([3, 1, 2]), 6, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(maximumproduct([4, 1, 3, 2]), 24, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(maximumproduct([-1, 0, 1, 3, 1]), 3, 'example 3')
+
+  def test_ex4(self):
+    self.assertEqual(maximumproduct([-8, 2, -9, 0, -4, 3]), 216, 'example 4')
+
+unittest.main()
diff --git a/challenge-218/roger-bell-west/python/ch-2.py b/challenge-218/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..7d16a57c01
--- /dev/null
+++ b/challenge-218/roger-bell-west/python/ch-2.py
@@ -0,0 +1,38 @@
+#! /usr/bin/python3
+
+def matrixscore(matrix0):
+  matrix = matrix0;
+  for i in range(len(matrix)):
+    if matrix[i][0] == 0:
+      for j in range(len(matrix[i])):
+        matrix[i][j] = 1 - matrix[i][j]
+  t = len(matrix) // 2
+  for i in range(1, len(matrix[0])):
+    c = 0
+    for j in range(len(matrix)):
+      if matrix[j][i] == 0:
+        c += 1
+    if c > t:
+      for j in range(len(matrix)):
+        matrix[j][i] = 1 - matrix[j][i] 
+  tot = 0
+  for m in matrix:
+    p = 0
+    for n in m:
+      p *= 2
+      if n == 1:
+        p += 1
+    tot += p
+  return tot
+
+import unittest
+
+class TestMatrixscore(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(matrixscore([[0, 0, 1, 1], [1, 0, 1, 0], [1, 1, 1, 0]]), 39, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(matrixscore([[0]]), 1, 'example 2')
+
+unittest.main()
diff --git a/challenge-218/roger-bell-west/raku/ch-1.p6 b/challenge-218/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..b1350b04bb
--- /dev/null
+++ b/challenge-218/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,31 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 4;
+
+is(maximumproduct([3, 1, 2]), 6, 'example 1');
+is(maximumproduct([4, 1, 3, 2]), 24, 'example 2');
+is(maximumproduct([-1, 0, 1, 3, 1]), 3, 'example 3');
+is(maximumproduct([-8, 2, -9, 0, -4, 3]), 216, 'example 4');
+
+sub maximumproduct(@lst) {
+    my @l = sort {$^a <=> $^b}, @lst;
+    my $b = @l.elems;
+    my @t;
+    for (0..3) -> $i {
+        my $p = 1;
+        if ($i > 0) {
+            for (0..$i-1) -> $j {
+                $p *= @l[$j];
+            }
+        }
+        if ($i < 3) {
+            for ($b-3+$i..$b-1) -> $j {
+                $p *= @l[$j];
+            }
+        }
+        @t.push($p);
+    }
+    return max(@t);
+}
diff --git a/challenge-218/roger-bell-west/raku/ch-2.p6 b/challenge-218/roger-bell-west/raku/ch-2.p6
new file mode 100755
index 0000000000..85cf63575d
--- /dev/null
+++ b/challenge-218/roger-bell-west/raku/ch-2.p6
@@ -0,0 +1,45 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 2;
+
+is(matrixscore([[0, 0, 1, 1], [1, 0, 1, 0], [1, 1, 1, 0]]), 39, 'example 1');
+is(matrixscore([[0]]), 1, 'example 2');
+
+sub matrixscore(@matrix0) {
+    my @matrix = map {$_.Array}, @matrix0;
+    for (0..@matrix.end) -> $i {
+        if (@matrix[$i][0] == 0) {
+            for (0..@matrix[0].end) -> $j {
+                @matrix[$i][$j] = 1 - @matrix[$i][$j];
+            }
+        }
+    }
+    my $t = (@matrix.elems / 2).Int;
+    for (1..@matrix[0].end) -> $i {
+        my $c = 0;
+        for (0..@matrix.end) -> $j {
+            if (@matrix[$j][$i] == 0) {
+                $c++;
+            }
+        }
+        if ($c > $t) {
+            for (0..@matrix.end) -> $j {
+                @matrix[$j][$i] = 1 - @matrix[$j][$i];
+            }
+        }
+    }
+    my $tot = 0;
+    for @matrix -> @m {
+        my $p = 0;
+        for @m -> $n {
+            $p *= 2;
+            if ($n == 1) {
+                $p++;
+            }
+        }
+        $tot += $p;
+    }
+    return $tot;
+}
diff --git a/challenge-218/roger-bell-west/ruby/ch-1.rb b/challenge-218/roger-bell-west/ruby/ch-1.rb
new file mode 100755
index 0000000000..2a52f10cf7
--- /dev/null
+++ b/challenge-218/roger-bell-west/ruby/ch-1.rb
@@ -0,0 +1,44 @@
+#! /usr/bin/ruby
+
+def maximumproduct(lst)
+  l = lst.sort
+  b = l.length
+  t = []
+  0.upto(3) do |i|
+    p = 1
+    if i > 0 then
+      0.upto(i-1) do |j|
+        p *= l[j]
+      end
+    end
+    if i < 3 then
+      (b - 3 + i).upto(b-1) do |j|
+        p *= l[j]
+      end
+    end
+    t.push(p)
+  end
+  return t.max
+end
+
+require 'test/unit'
+
+class TestMaximumproduct < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(6, maximumproduct([3, 1, 2]))
+  end
+
+  def test_ex2
+    assert_equal(24, maximumproduct([4, 1, 3, 2]))
+  end
+
+  def test_ex3
+    assert_equal(3, maximumproduct([-1, 0, 1, 3, 1]))
+  end
+
+  def test_ex4
+    assert_equal(216, maximumproduct([-8, 2, -9, 0, -4, 3]))
+  end
+
+end
diff --git a/challenge-218/roger-bell-west/ruby/ch-2.rb b/challenge-218/roger-bell-west/ruby/ch-2.rb
new file mode 100755
index 0000000000..5e032504ce
--- /dev/null
+++ b/challenge-218/roger-bell-west/ruby/ch-2.rb
@@ -0,0 +1,52 @@
+#! /usr/bin/ruby
+
+def matrixscore(matrix0)
+  matrix = matrix0
+  0.upto(matrix.length-1) do |i|
+    if matrix[i][0] == 0 then
+      0.upto(matrix[i].length-1) do |j|
+        matrix[i][j] = 1 - matrix[i][j]
+      end
+    end
+  end
+  t = matrix.length.div(2)
+  1.upto(matrix[0].length-1) do |i|
+    c = 0
+    0.upto(matrix.length-1) do |j|
+      if matrix[j][i] == 0 then
+        c += 1
+        end
+    end
+    if c > t then
+      0.upto(matrix.length-1) do |j|
+        matrix[j][i] = 1 - matrix[j][i]
+      end
+    end
+  end
+  tot = 0
+  matrix.each do |m|
+    p = 0
+    m.each do |n|
+      p *= 2
+      if n == 1 then
+        p += 1
+      end
+    end
+    tot += p
+  end
+  return tot
+end
+
+require 'test/unit'
+
+class TestMatrixscore < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(39, matrixscore([[0, 0, 1, 1], [1, 0, 1, 0], [1, 1, 1, 0]]))
+  end
+
+  def test_ex2
+    assert_equal(1, matrixscore([[0]]))
+  end
+
+end
diff --git a/challenge-218/roger-bell-west/rust/ch-1.rs b/challenge-218/roger-bell-west/rust/ch-1.rs
new file mode 100755
index 0000000000..65956f73be
--- /dev/null
+++ b/challenge-218/roger-bell-west/rust/ch-1.rs
@@ -0,0 +1,44 @@
+#! /bin/sh
+//usr/bin/env rustc --test $0 -o ${0}x && ./${0}x --nocapture; rm -f ${0}x ; exit
+
+#[test]
+fn test_ex1() {
+    assert_eq!(maximumproduct(vec![3, 1, 2]), 6);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(maximumproduct(vec![4, 1, 3, 2]), 24);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(maximumproduct(vec![-1, 0, 1, 3, 1]), 3);
+}
+
+#[test]
+fn test_ex4() {
+    assert_eq!(maximumproduct(vec![-8, 2, -9, 0, -4, 3]), 216);
+}
+
+fn maximumproduct(lst: Vec<i32>) -> i32 {
+    let mut l = lst;
+    l.sort();
+    let b = l.len();
+    let mut t: Vec<i32> = Vec::new();
+    for i in 0..=3 {
+        let mut p = 1;
+        if i > 0 {
+            for j in 0..i {
+                p *= l[j];
+            }
+        }
+        if i < 3 {
+            for j in b - 3 + i..b {
+                p *= l[j];
+            }
+        }
+        t.push(p);
+    }
+    t.into_iter().max().unwrap()
+}
diff --git a/challenge-218/roger-bell-west/rust/ch-2.rs b/challenge-218/roger-bell-west/rust/ch-2.rs
new file mode 100755
index 0000000000..f17213ce27
--- /dev/null
+++ b/challenge-218/roger-bell-west/rust/ch-2.rs
@@ -0,0 +1,52 @@
+#! /bin/sh
+//usr/bin/env rustc --test $0 -o ${0}x && ./${0}x --nocapture; rm -f ${0}x ; exit
+
+#[test]
+fn test_ex1() {
+    assert_eq!(
+        matrixscore(vec![vec![0, 0, 1, 1], vec![1, 0, 1, 0], vec![1, 1, 1, 0]]),
+        39
+    );
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(matrixscore(vec![vec![0]]), 1);
+}
+
+fn matrixscore(matrix0: Vec<Vec<u8>>) -> u32 {
+    let mut matrix = matrix0;
+    for i in 0..matrix.len() {
+        if matrix[i][0] == 0 {
+            for j in 0..matrix[i].len() {
+                matrix[i][j] = 1 - matrix[i][j];
+            }
+        }
+    }
+    let t = matrix.len() / 2;
+    for i in 1..matrix[0].len() {
+        let mut c = 0;
+        for j in 0..matrix.len() {
+            if matrix[j][i] == 0 {
+                c += 1;
+            }
+        }
+        if c > t {
+            for j in 0..matrix.len() {
+                matrix[j][i] = 1 - matrix[j][i];
+            }
+        }
+    }
+    let mut tot = 0;
+    for m in matrix {
+        let mut p = 0;
+        for n in m {
+            p *= 2;
+            if n == 1 {
+                p += 1;
+            }
+        }
+        tot += p;
+    }
+    tot
+}
diff --git a/challenge-218/roger-bell-west/tests.yaml b/challenge-218/roger-bell-west/tests.yaml
new file mode 100644
index 0000000000..ed901a139a
--- /dev/null
+++ b/challenge-218/roger-bell-west/tests.yaml
@@ -0,0 +1,49 @@
+---
+ch-1:
+  - function: maximumproduct
+    arguments:
+      - 3
+      - 1
+      - 2
+    result: 6
+  - arguments:
+      - 4
+      - 1
+      - 3
+      - 2
+    result: 24
+  - arguments:
+      - -1
+      - 0
+      - 1
+      - 3
+      - 1
+    result: 3
+  - arguments:
+      - -8
+      - 2
+      - -9
+      - 0
+      - -4
+      - 3
+    result: 216
+ch-2:
+  - function: matrixscore
+    arguments:
+      - - 0
+        - 0
+        - 1
+        - 1
+      - - 1
+        - 0
+        - 1
+        - 0
+      - - 1
+        - 1
+        - 1
+        - 0
+    result: 39
+  - arguments:
+      - - 0
+    result: 1
+ 
-- 
cgit