Merge pull request #9382 from Firedrake/rogerbw-challenge-251

RogerBW solutions for challenge no. 251

21 files changed, 1100 insertions, 0 deletions

diff --git a/challenge-251/roger-bell-west/javascript/ch-1.js b/challenge-251/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..16d97f30e4
--- /dev/null
+++ b/challenge-251/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,49 @@
+#! /usr/bin/node
+
+"use strict"
+
+function concat(a0, b0) {
+    if (b0 == 0) {
+        return 10 * a0;
+    }
+    let a = a0;
+    let b = b0;
+    while (b > 0) {
+        a *= 10;
+        b = Math.floor(b / 10);
+    }
+    return a + b0;
+}
+
+function concatenationvalue(a) {
+    let t = 0;
+    let ms = Math.floor((a.length - 1) / 2);
+    for (let i = 0; i <= ms; i++) {
+        const j = a.length - 1 - i;
+        if (j == i) {
+            t += a[i];
+        } else {
+            t += concat(a[i], a[j]);
+        }
+    }
+    return t;
+}
+
+if (concatenationvalue([6, 12, 25, 1]) == 1286) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (concatenationvalue([10, 7, 31, 5, 2, 2]) == 489) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (concatenationvalue([1, 2, 10]) == 112) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-251/roger-bell-west/javascript/ch-2.js b/challenge-251/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..94f11a4824
--- /dev/null
+++ b/challenge-251/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,53 @@
+#! /usr/bin/node
+
+"use strict"
+
+function luckynumbers (a) {
+    var maxs = new Set();
+    for (let x = 0; x < a[0].length; x++) {
+        var max = [0, 0, 0];
+        for (let y = 0; y < a.length; y++) {
+            if (a[y][x] > max[0]) {
+                max = [a[y][x], y, x];
+            }
+        }
+        maxs.add(max);
+    }
+    var mins = new Set();
+    for (let y = 0; y < a.length; y++) {
+        var min = [a[y][0], y, 0];
+        for (let x = 0; x < a[0].length; x++) {
+            if (a[y][x] < min[0]) {
+                min = [a[y][x], y, x];
+            }
+        }
+        mins.add(min);
+    }
+    for (let i of maxs) {
+        for (let j of mins) {
+            if (i[0] == j[0] && i[1] == j[1] && i[2] == j[2]) {
+                return i[0];
+            }
+        }
+    }
+    return -1;
+}
+
+if (luckynumbers([[3, 7, 9], [9, 11, 13], [15, 16, 17]]) == 15) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (luckynumbers([[1, 10, 4, 2], [9, 3, 8, 7], [15, 16, 17, 12]]) == 12) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (luckynumbers([[7, 8], [1, 2]]) == 7) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-251/roger-bell-west/kotlin/ch-1.kt b/challenge-251/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..7e0eb3c79a
--- /dev/null
+++ b/challenge-251/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,48 @@
+fun concat(a0: Int, b0: Int): Int {
+    if (b0 == 0) {
+        return 10 * a0
+    }
+    var a = a0
+    var b = b0
+    while (b > 0) {
+        a *= 10
+        b /= 10
+    }
+    return a + b0
+}
+
+fun concatenationvalue(a: List<Int>): Int {
+    var t = 0
+    for (i in 0..(a.size - 1) / 2) {
+        val j = a.size - 1 - i
+        if (j == i) {
+            t += a[i]
+        } else {
+            t += concat(a[i], a[j])
+        }
+    }
+    return t
+}
+
+fun main() {
+
+    if (concatenationvalue(listOf(6, 12, 25, 1)) == 1286) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (concatenationvalue(listOf(10, 7, 31, 5, 2, 2)) == 489) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (concatenationvalue(listOf(1, 2, 10)) == 112) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-251/roger-bell-west/kotlin/ch-2.kt b/challenge-251/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..863bfebad4
--- /dev/null
+++ b/challenge-251/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,50 @@
+fun luckynumbers (a: List<List<Int>>): Int {
+    var maxs = mutableSetOf<List<Int>>()
+    for (x in 0 .. a[0].size - 1) {
+        var max = listOf(0, 0, 0)
+        for (y in 0 .. a.size - 1) {
+            if (a[y][x] > max[0]) {
+                max = listOf(a[y][x], y, x)
+            }
+        }
+        maxs.add(max)
+    }
+    var mins = mutableSetOf<List<Int>>()
+    for (y in 0 .. a.size - 1) {
+        var min = listOf(a[y][0], y, 0)
+        for (x in 0 .. a[0].size - 1) {
+            if (a[y][x] < min[0]) {
+                min = listOf(a[y][x], y, x)
+            }
+        }
+        mins.add(min)
+    }
+    val i = ArrayList(maxs.intersect(mins))
+    if (i.size > 0) {
+        return i[0][0]
+    }
+    return -1
+}
+
+fun main() {
+
+    if (luckynumbers(listOf(listOf(3, 7, 9), listOf(9, 11, 13), listOf(15, 16, 17))) == 15) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (luckynumbers(listOf(listOf(1, 10, 4, 2), listOf(9, 3, 8, 7), listOf(15, 16, 17, 12))) == 12) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (luckynumbers(listOf(listOf(7, 8), listOf(1, 2))) == 7) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-251/roger-bell-west/lua/ch-1.lua b/challenge-251/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..e893bf6fbd
--- /dev/null
+++ b/challenge-251/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,49 @@
+#! /usr/bin/lua
+
+function concat(a0, b0)
+   if b0 == 0 then
+      return 10 * a0
+   end
+   local a = a0
+   local b = b0
+   while b > 0 do
+      a = a * 10
+      b = math.floor(b / 10)
+   end
+   return a + b0
+end
+
+function concatenationvalue(a)
+   local t = 0
+   for i = 1, math.floor((#a + 1) / 2) do
+      local j = #a + 1 - i
+      if j == i then
+         t = t + a[i]
+      else
+         t = t + concat(a[i], a[j])
+      end
+   end
+   return t
+end
+
+if concatenationvalue({6, 12, 25, 1}) == 1286 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if concatenationvalue({10, 7, 31, 5, 2, 2}) == 489 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if concatenationvalue({1, 2, 10}) == 112 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-251/roger-bell-west/lua/ch-2.lua b/challenge-251/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..b6f31930c0
--- /dev/null
+++ b/challenge-251/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,54 @@
+#! /usr/bin/lua
+
+function luckynumbers(a)
+   local maxs = {}
+   for x = 1, #(a[1]) do
+      local max = {0, 0, 0}
+      for y = 1, #a do
+         if a[y][x] > max[1] then
+            max = {a[y][x], y, x}
+         end
+      end
+      table.insert(maxs, max)
+   end
+   local mins = {}
+   for y = 1, #a do
+      local min = {a[y][1], y, 1}
+      for x = 1, #(a[1]) do
+         if a[y][x] < min[1] then
+            min = {a[y][x], y, x}
+         end
+      end
+      table.insert(mins, min)
+   end
+   for i, v in ipairs(mins) do
+      for j, w in ipairs(maxs) do
+         if v[1] == w[1] and v[2] == w[2] and v[3] == w[3] then
+            return v[1]
+         end
+      end
+   end
+   return -1
+end
+
+if luckynumbers({{3, 7, 9}, {9, 11, 13}, {15, 16, 17}}) == 15 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if luckynumbers({{1, 10, 4, 2}, {9, 3, 8, 7}, {15, 16, 17, 12}}) == 12 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if luckynumbers({{7, 8}, {1, 2}}) == 7 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-251/roger-bell-west/perl/ch-1.pl b/challenge-251/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..8dab36aa12
--- /dev/null
+++ b/challenge-251/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,37 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 3;
+
+is(concatenationvalue([6, 12, 25, 1]), 1286, 'example 1');
+is(concatenationvalue([10, 7, 31, 5, 2, 2]), 489, 'example 2');
+is(concatenationvalue([1, 2, 10]), 112, 'example 3');
+
+sub concat($a0, $b0) {
+  if ($b0 == 0) {
+    return 10 * $a0;
+  }
+  my $a = $a0;
+  my $b = $b0;
+  while ($b > 0) {
+    $a *= 10;
+    $b = int($b/10);
+  }
+  return $a + $b0;
+}
+
+sub concatenationvalue($a) {
+  my $t = 0;
+  foreach my $i (0 .. int($#{$a} / 2)) {
+    my $j = $#{$a} - $i;
+    if ($j == $i) {
+      $t += $a->[$i];
+    } else {
+      $t += concat($a->[$i], $a->[$j]);
+    }
+  }
+  return $t;
+}
diff --git a/challenge-251/roger-bell-west/perl/ch-2.pl b/challenge-251/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..157e4aa828
--- /dev/null
+++ b/challenge-251/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,42 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 3;
+
+is(luckynumbers([[3, 7, 9], [9, 11, 13], [15, 16, 17]]), 15, 'example 1');
+is(luckynumbers([[1, 10, 4, 2], [9, 3, 8, 7], [15, 16, 17, 12]]), 12, 'example 2');
+is(luckynumbers([[7, 8], [1, 2]]), 7, 'example 3');
+
+use Storable qw(freeze thaw);
+
+sub luckynumbers($a) {
+  my $maxs = {};
+  foreach my $x (0 .. $#{$a->[0]}) {
+    my $max = [0, 0, 0];
+    foreach my $y (0 .. $#{$a}) {
+      if ($a->[$y][$x] > $max->[0]) {
+        $max = [$a->[$y][$x], $y, $x];
+      }
+    }
+    $maxs->{freeze($max)} = 1;
+  }
+  my $mins = {};
+  foreach my $y (0 .. $#{$a}) {
+    my $min = [$a->[$y][0], $y, 0];
+    foreach my $x (0 .. $#{$a->[0]}) {
+      if ($a->[$y][$x] < $min->[0]) {
+        $min = [$a->[$y][$x], $y, $x];
+      }
+    }
+    $mins->{freeze($min)} = 1;
+  }
+  foreach my $i (keys %{$maxs}) {
+    if (exists $mins->{$i}) {
+      return thaw($i)->[0];
+    }
+  }
+  return -1;
+}
diff --git a/challenge-251/roger-bell-west/postscript/ch-1.ps b/challenge-251/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..ee5715d948
--- /dev/null
+++ b/challenge-251/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,79 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/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
+
+/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
+
+
+% end included library code
+
+/concat {
+    0 dict begin
+    /b0 exch def
+    /a0 exch def
+    b0 0 eq {
+        10 a0 mul
+    } {
+        /a a0 def
+        /b b0 def
+        {
+            b 0 le {
+                exit
+            } if
+            /a a 10 mul def
+            /b b 10 idiv def
+        } loop
+        a b0 add
+    } ifelse
+    end
+} bind def
+
+/concatenationvalue {
+    0 dict begin
+    /a exch def
+    0
+    0 1 a length 1 sub 2 idiv {
+        /i exch def
+        /j a length 1 sub i sub def
+        i j eq {
+            a i get add
+        } {
+            a i get a j get concat add
+        } ifelse
+    } for
+} bind def
+
+(concatenationvalue) test.start
+[6 12 25 1] concatenationvalue 1286 eq test
+[10 7 31 5 2 2] concatenationvalue 489 eq test
+[1 2 10] concatenationvalue 112 eq test
+test.end
diff --git a/challenge-251/roger-bell-west/postscript/ch-2.ps b/challenge-251/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..9020e475b0
--- /dev/null
+++ b/challenge-251/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,149 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/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
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+/deepeq {
+    2 dict begin
+    /a exch def
+    /b exch def
+    a type b type eq {
+        a type /dicttype eq {
+            a length b length eq {
+                <<
+                    a {
+                        pop
+                        true
+                    } forall
+                    b {
+                        pop
+                        true
+                    } forall
+                >>
+                true exch
+                {
+                    pop
+                    dup a exch known {
+                        dup b exch known {
+                            dup a exch get exch b exch get deepeq not {
+                                pop false
+                            } if
+                        } {
+                            false
+                        } ifelse
+                    } {
+                        false
+                    } ifelse
+                } forall
+            } {
+                false
+            } ifelse
+        } {
+            a type dup /arraytype eq exch /stringtype eq or {
+                a length b length eq {
+                    true
+                    0 1 a length 1 sub {
+                        dup a exch get exch b exch get deepeq not {
+                            pop false
+                            exit
+                        } if
+                    } for
+                } {
+                    false
+                } ifelse
+            } {
+                a b eq
+            } ifelse
+        } ifelse
+    } {
+        false
+    } ifelse
+    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
+
+
+% end included library code
+
+/luckynumbers {
+    0 dict begin
+    /a exch def
+    /maxs [
+        0 1 a 0 get length 1 sub {
+            /x exch def
+            /max [ 0 0 0 ] def
+            0 1 a length 1 sub {
+                /y exch def
+                a y get x get max 0 get gt {
+                    /max [ a y get x get y x ] def
+                } if
+            } for
+            max
+        } for
+    ] def
+    /mins [
+        0 1 a length 1 sub {
+            /y exch def
+            /min [ a y get 0 get y 0 ] def
+            0 1 a 0 get length 1 sub {
+                /x exch def
+                a y get x get min 0 get lt {
+                    /min [ a y get x get y x ] def
+                } if
+            } for
+            min
+        } for
+    ] def
+    -1
+    /ex false def
+    maxs {
+        /i exch def
+        mins {
+            /j exch def
+            i j deepeq {
+                pop i 0 get
+                /ex true def
+                exit
+            } if
+        } forall
+        ex {
+            exit
+        } if
+    } forall
+    end
+} bind def
+
+(luckynumbers) test.start
+[[3 7 9] [9 11 13] [15 16 17]] luckynumbers 15 eq test
+[[1 10 4 2] [9 3 8 7] [15 16 17 12]] luckynumbers 12 eq test
+[[7 8] [1 2]] luckynumbers 7 eq test
+test.end
diff --git a/challenge-251/roger-bell-west/python/ch-1.py b/challenge-251/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..8f81c81b2e
--- /dev/null
+++ b/challenge-251/roger-bell-west/python/ch-1.py
@@ -0,0 +1,36 @@
+#! /usr/bin/python3
+
+def concat(a0, b0):
+  if b0 == 0:
+    return 10 * a0
+  a = a0
+  b = b0
+  while b > 0:
+    a *= 10
+    b = int(b / 10)
+  return a + b0
+
+def concatenationvalue(a):
+  t = 0
+  for i in range(int((len(a) - 1)/2) + 1):
+    j = len(a) - 1 - i
+    if j == i:
+      t += a[i]
+    else:
+      t += concat(a[i], a[j])
+  return t
+
+import unittest
+
+class TestConcatenationvalue(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(concatenationvalue([6, 12, 25, 1]), 1286, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(concatenationvalue([10, 7, 31, 5, 2, 2]), 489, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(concatenationvalue([1, 2, 10]), 112, 'example 3')
+
+unittest.main()
diff --git a/challenge-251/roger-bell-west/python/ch-2.py b/challenge-251/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..9de893dc56
--- /dev/null
+++ b/challenge-251/roger-bell-west/python/ch-2.py
@@ -0,0 +1,36 @@
+#! /usr/bin/python3
+
+def luckynumbers(a):
+  maxs = set()
+  for x in range(len(a[0])):
+    max = (0, 0, 0)
+    for y in range(len(a)):
+      if a[y][x] > max[0]:
+        max = (a[y][x], y, x)
+    maxs.add(max)
+  mins = set()
+  for y in range(len(a)):
+    min = (a[y][0], y, 0)
+    for x in range(len(a[0])):
+      if a[y][x] < min[0]:
+        min = (a[y][x], y, x)
+    mins.add(min)
+  i = list(maxs.intersection(mins))
+  if len(i) > 0:
+    return i[0][0]
+  return -1
+
+import unittest
+
+class TestLuckynumbers(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(luckynumbers([[3, 7, 9], [9, 11, 13], [15, 16, 17]]), 15, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(luckynumbers([[1, 10, 4, 2], [9, 3, 8, 7], [15, 16, 17, 12]]), 12, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(luckynumbers([[7, 8], [1, 2]]), 7, 'example 3')
+
+unittest.main()
diff --git a/challenge-251/roger-bell-west/raku/ch-1.p6 b/challenge-251/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..696eda5c84
--- /dev/null
+++ b/challenge-251/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,35 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 3;
+
+is(concatenationvalue([6, 12, 25, 1]), 1286, 'example 1');
+is(concatenationvalue([10, 7, 31, 5, 2, 2]), 489, 'example 2');
+is(concatenationvalue([1, 2, 10]), 112, 'example 3');
+
+sub concat($a0, $b0) {
+    if ($b0 == 0) {
+        return 10 * $a0;
+    }
+    my $a = $a0;
+    my $b = $b0;
+    while ($b > 0) {
+        $a *= 10;
+        $b = floor($b/10);
+    }
+    return $a + $b0;
+}
+
+sub concatenationvalue(@a) {
+    my $t = 0;
+    for 0 .. floor((@a.elems-1) / 2) -> $i {
+        my $j = @a.elems - 1 - $i;
+        if ($j == $i) {
+            $t += @a[$i];
+        } else {
+            $t += concat(@a[$i], @a[$j]);
+        }
+    }
+    return $t
+}
diff --git a/challenge-251/roger-bell-west/raku/ch-2.p6 b/challenge-251/roger-bell-west/raku/ch-2.p6
new file mode 100755
index 0000000000..93f748d9f1
--- /dev/null
+++ b/challenge-251/roger-bell-west/raku/ch-2.p6
@@ -0,0 +1,42 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 3;
+
+is(luckynumbers([[3, 7, 9], [9, 11, 13], [15, 16, 17]]), 15, 'example 1');
+is(luckynumbers([[1, 10, 4, 2], [9, 3, 8, 7], [15, 16, 17, 12]]), 12, 'example 2');
+is(luckynumbers([[7, 8], [1, 2]]), 7, 'example 3');
+
+sub luckynumbers(@a) {
+    my $maxs = SetHash.new;
+    for 0 .. @a[0].end() -> $x {
+        my $max = [0, 0, 0];
+        for 0 .. @a.end -> $y {
+            if @a[$y][$x] > $max[0] {
+                $max = [@a[$y][$x], $y, $x];
+            }
+        }
+        $maxs{$max}++;
+    }
+    my $mins = SetHash.new;
+    for 0 .. @a.end() -> $y {
+        my $min = [@a[$y][0], $y, 0];
+        for 0 .. @a[0].end -> $x {
+            if @a[$y][$x] < $min[0] {
+                $min = [@a[$y][$x], $y, $x];
+            }
+        }
+        $mins{$min}++;
+    }
+    for $maxs.keys -> $i {
+        for $mins.keys -> $j {
+            if ($i[0] == $j[0] &&
+                          $i[1] == $j[1] &&
+                                    $i[2] == $j[2]) {
+                return $i[0];
+            }
+        }
+    }
+    return -1;
+}
diff --git a/challenge-251/roger-bell-west/ruby/ch-1.rb b/challenge-251/roger-bell-west/ruby/ch-1.rb
new file mode 100755
index 0000000000..2154ed2189
--- /dev/null
+++ b/challenge-251/roger-bell-west/ruby/ch-1.rb
@@ -0,0 +1,45 @@
+#! /usr/bin/ruby
+
+def concat(a0, b0)
+  if (b0 == 0) then
+    return 10 * a0
+  end
+  a = a0
+  b = b0
+  while (b > 0) do
+    a *= 10;
+    b = (b / 10).floor
+  end
+  return a + b0
+end
+
+def concatenationvalue(a)
+  t = 0
+  0.upto(((a.length - 1) / 2).floor) do |i|
+    j = a.length - 1 - i
+    if (j == i) then
+      t += a[i]
+    else
+      t += concat(a[i], a[j])
+    end
+  end
+  return t
+end
+
+require 'test/unit'
+
+class TestConcatenationvalue < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(1286, concatenationvalue([6, 12, 25, 1]))
+  end
+
+  def test_ex2
+    assert_equal(489, concatenationvalue([10, 7, 31, 5, 2, 2]))
+  end
+
+  def test_ex3
+    assert_equal(112, concatenationvalue([1, 2, 10]))
+  end
+
+end
diff --git a/challenge-251/roger-bell-west/ruby/ch-2.rb b/challenge-251/roger-bell-west/ruby/ch-2.rb
new file mode 100755
index 0000000000..4c7966b290
--- /dev/null
+++ b/challenge-251/roger-bell-west/ruby/ch-2.rb
@@ -0,0 +1,49 @@
+#! /usr/bin/ruby
+
+require 'set'
+
+def luckynumbers(a)
+  maxs = Set.new
+  0.upto(a[0].length - 1) do |x|
+    max = [0, 0, 0]
+    0.upto(a.length - 1) do |y|
+      if a[y][x] > max[0] then
+        max = [a[y][x], y, x]
+      end
+    end
+    maxs.add(Marshal.dump(max))
+  end
+  mins = Set.new
+  0.upto(a.length - 1) do |y|
+    min = [a[y][0], y, 0]
+    0.upto(a[0].length - 1) do |x|
+      if a[y][x] < min[0] then
+        min = [a[y][x], y, x]
+      end
+    end
+    mins.add(Marshal.dump(min))
+  end
+  i = (maxs & mins).to_a
+  if i.length > 0 then
+    return Marshal.load(i[0])[0]
+  end
+  return -1
+end
+
+require 'test/unit'
+
+class TestLuckynumbers < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(15, luckynumbers([[3, 7, 9], [9, 11, 13], [15, 16, 17]]))
+  end
+
+  def test_ex2
+    assert_equal(12, luckynumbers([[1, 10, 4, 2], [9, 3, 8, 7], [15, 16, 17, 12]]))
+  end
+
+  def test_ex3
+    assert_equal(7, luckynumbers([[7, 8], [1, 2]]))
+  end
+
+end
diff --git a/challenge-251/roger-bell-west/rust/ch-1.rs b/challenge-251/roger-bell-west/rust/ch-1.rs
new file mode 100755
index 0000000000..d6dc693d03
--- /dev/null
+++ b/challenge-251/roger-bell-west/rust/ch-1.rs
@@ -0,0 +1,43 @@
+#! /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!(concatenationvalue(vec![6, 12, 25, 1]), 1286);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(concatenationvalue(vec![10, 7, 31, 5, 2, 2]), 489);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(concatenationvalue(vec![1, 2, 10]), 112);
+}
+
+fn concat(a0: u32, b0: u32) -> u32 {
+    if b0 == 0 {
+        return 10 * a0;
+    }
+    let mut a = a0;
+    let mut b = b0;
+    while b > 0 {
+        a *= 10;
+        b /= 10;
+    }
+    a + b0
+}
+
+fn concatenationvalue(a: Vec<u32>) -> u32 {
+    let mut t = 0;
+    for i in 0 ..= (a.len()-1) / 2 {
+        let j = a.len() - 1 - i;
+        if j == i {
+            t += a[i];
+        } else {
+            t += concat(a[i], a[j]);
+        }
+    }
+    t
+}
diff --git a/challenge-251/roger-bell-west/rust/ch-2.rs b/challenge-251/roger-bell-west/rust/ch-2.rs
new file mode 100755
index 0000000000..ffc50172c1
--- /dev/null
+++ b/challenge-251/roger-bell-west/rust/ch-2.rs
@@ -0,0 +1,47 @@
+#! /bin/sh
+//usr/bin/env rustc --test $0 -o ${0}x && ./${0}x --nocapture; rm -f ${0}x ; exit
+
+use std::collections::HashSet;
+
+#[test]
+fn test_ex1() {
+    assert_eq!(luckynumbers(vec![vec![3, 7, 9], vec![9, 11, 13], vec![15, 16, 17]]), 15);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(luckynumbers(vec![vec![1, 10, 4, 2], vec![9, 3, 8, 7], vec![15, 16, 17, 12]]), 12);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(luckynumbers(vec![vec![7, 8], vec![1, 2]]), 7);
+}
+
+fn luckynumbers(a: Vec<Vec<i32>>) -> i32 {
+    let mut maxs = HashSet::new();
+    for x in 0 .. a[0].len() {
+        let mut max = (0, 0, 0);
+        f