Merge pull request #12687 from Firedrake/rogerbw-challenge-339

RogerBW solutions for challenge no. 339

25 files changed, 1053 insertions, 0 deletions

diff --git a/challenge-339/roger-bell-west/crystal/ch-1.cr b/challenge-339/roger-bell-west/crystal/ch-1.cr
new file mode 100755
index 0000000000..5f13f204b3
--- /dev/null
+++ b/challenge-339/roger-bell-west/crystal/ch-1.cr
@@ -0,0 +1,39 @@
+#! /usr/bin/crystal
+
+def maxdiff(a)
+  md = 0
+  0.upto(a.size - 2) do |w|
+    (w + 1).upto(a.size - 1) do |x|
+      (w + 1).upto(a.size - 2) do |y|
+        if y != x
+          (y + 1).upto(a.size - 1) do |z|
+            if z != x
+              v = (a[w] * a[x] - a[y] * a[z]).abs
+              md = [md, v].max
+            end
+          end
+        end
+      end
+    end
+  end
+  md
+end
+
+require "spec"
+describe "maxdiff" do
+  it "test_ex1" do
+    maxdiff([5, 9, 3, 4, 6]).should eq 42
+  end
+  it "test_ex2" do
+    maxdiff([1, -2, 3, -4]).should eq 10
+  end
+  it "test_ex3" do
+    maxdiff([-3, -1, -2, -4]).should eq 10
+  end
+  it "test_ex4" do
+    maxdiff([10, 2, 0, 5, 1]).should eq 50
+  end
+  it "test_ex5" do
+    maxdiff([7, 8, 9, 10, 10]).should eq 44
+  end
+end
diff --git a/challenge-339/roger-bell-west/crystal/ch-2.cr b/challenge-339/roger-bell-west/crystal/ch-2.cr
new file mode 100755
index 0000000000..60b0892ca7
--- /dev/null
+++ b/challenge-339/roger-bell-west/crystal/ch-2.cr
@@ -0,0 +1,30 @@
+#! /usr/bin/crystal
+
+def peakpoint(a)
+  h = 0
+  o = 0
+  a.each do |p|
+    h += p
+    o = [o, h].max
+  end
+  o
+end
+
+require "spec"
+describe "peakpoint" do
+  it "test_ex1" do
+    peakpoint([-5, 1, 5, -9, 2]).should eq 1
+  end
+  it "test_ex2" do
+    peakpoint([10, 10, 10, -25]).should eq 30
+  end
+  it "test_ex3" do
+    peakpoint([3, -4, 2, 5, -6, 1]).should eq 6
+  end
+  it "test_ex4" do
+    peakpoint([-1, -2, -3, -4]).should eq 0
+  end
+  it "test_ex5" do
+    peakpoint([-10, 15, 5]).should eq 10
+  end
+end
diff --git a/challenge-339/roger-bell-west/javascript/ch-1.js b/challenge-339/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..7097a84470
--- /dev/null
+++ b/challenge-339/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,53 @@
+#! /usr/bin/node
+
+function maxdiff(a) {
+    let md = 0;
+    for (let w = 0; w < a.length - 1; w++) {
+        for (let x = w + 1; x < a.length; x++) {
+            for (let y = w + 1; y < a.length - 1; y++) {
+                if (y != x) {
+                    for (let z = y + 1; z < a.length; z++) {
+                        if (z != x) {
+                            const v = Math.abs(a[w] * a[x] - a[y] * a[z]);
+                            md = Math.max(md, v)
+                        }
+                    }
+                }
+            }
+        }
+    }
+    return md;
+}-
+
+"use strict"
+
+if (maxdiff([5, 9, 3, 4, 6]) == 42) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (maxdiff([1, -2, 3, -4]) == 10) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (maxdiff([-3, -1, -2, -4]) == 10) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (maxdiff([10, 2, 0, 5, 1]) == 50) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (maxdiff([7, 8, 9, 10, 10]) == 44) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-339/roger-bell-west/javascript/ch-2.js b/challenge-339/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..cf5a69d9ab
--- /dev/null
+++ b/challenge-339/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,44 @@
+#! /usr/bin/node
+
+"use strict"
+
+function peakpoint(a) {
+    let h = 0;
+    let o = 0;
+    for (let p of a) {
+        h += p;
+        o = Math.max(o, h);
+    }
+    return o;
+}
+
+if (peakpoint([-5, 1, 5, -9, 2]) == 1) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (peakpoint([10, 10, 10, -25]) == 30) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (peakpoint([3, -4, 2, 5, -6, 1]) == 6) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (peakpoint([-1, -2, -3, -4]) == 0) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (peakpoint([-10, 15, 5]) == 10) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-339/roger-bell-west/kotlin/ch-1.kt b/challenge-339/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..fcc0931ee6
--- /dev/null
+++ b/challenge-339/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,53 @@
+fun maxdiff(a: List<Int>): Int {
+    var md = 0
+    for (w in 0 .. a.size - 2) {
+        for (x in w + 1 .. a.size - 1) {
+            for (y in w + 1 .. a.size - 2) {
+                if (y != x) {
+                    for (z in y + 1 .. a.size - 1) {
+                        if (z != x) {
+                            val v = Math.abs(a[w] * a[x] - a[y] * a[z])
+                            md = listOf(md, v).maxOrNull()!!
+                        }
+                    }
+                }
+            }
+        }
+    }
+    return md
+}
+
+fun main() {
+
+    if (maxdiff(listOf(5, 9, 3, 4, 6)) == 42) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (maxdiff(listOf(1, -2, 3, -4)) == 10) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (maxdiff(listOf(-3, -1, -2, -4)) == 10) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (maxdiff(listOf(10, 2, 0, 5, 1)) == 50) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (maxdiff(listOf(7, 8, 9, 10, 10)) == 44) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-339/roger-bell-west/kotlin/ch-2.kt b/challenge-339/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..60963e5b66
--- /dev/null
+++ b/challenge-339/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,44 @@
+fun peakpoint(a: List<Int>): Int {
+    var h = 0
+    var o = 0
+    for (p in a) {
+        h += p
+        o = listOf(o, h).maxOrNull()!!
+    }
+    return o
+}
+
+fun main() {
+
+    if (peakpoint(listOf(-5, 1, 5, -9, 2)) == 1) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (peakpoint(listOf(10, 10, 10, -25)) == 30) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (peakpoint(listOf(3, -4, 2, 5, -6, 1)) == 6) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (peakpoint(listOf(-1, -2, -3, -4)) == 0) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (peakpoint(listOf(-10, 15, 5)) == 10) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-339/roger-bell-west/lua/ch-1.lua b/challenge-339/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..681ebd8b7b
--- /dev/null
+++ b/challenge-339/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,56 @@
+#! /usr/bin/lua
+
+function maxdiff(a)
+   local md = 0
+   for w = 1, #a - 1 do
+      for x = w + 1, #a do
+         for y = w + 1, #a - 1 do
+            if y ~= x then
+               for z = y + 1, #a do
+                  if z ~= x then
+                     v = math.abs(a[w] * a[x] - a[y] * a[z])
+                     md = math.max(md, v)
+                  end
+               end
+            end
+         end
+      end
+   end
+   return md
+end
+
+if maxdiff({5, 9, 3, 4, 6}) == 42 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if maxdiff({1, -2, 3, -4}) == 10 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if maxdiff({-3, -1, -2, -4}) == 10 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if maxdiff({10, 2, 0, 5, 1}) == 50 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if maxdiff({7, 8, 9, 10, 10}) == 44 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-339/roger-bell-west/lua/ch-2.lua b/challenge-339/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..fe1f83e11c
--- /dev/null
+++ b/challenge-339/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,47 @@
+#! /usr/bin/lua
+
+function peakpoint(a)
+   local h = 0
+   local o = 0
+   for _, p in ipairs(a) do
+      h = h + p
+      o = math.max(o, h)
+   end
+   return o
+end
+
+if peakpoint({-5, 1, 5, -9, 2}) == 1 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if peakpoint({10, 10, 10, -25}) == 30 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if peakpoint({3, -4, 2, 5, -6, 1}) == 6 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if peakpoint({-1, -2, -3, -4}) == 0 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if peakpoint({-10, 15, 5}) == 10 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-339/roger-bell-west/perl/ch-1.pl b/challenge-339/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..51645f6cd9
--- /dev/null
+++ b/challenge-339/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,33 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 5;
+
+is(maxdiff([5, 9, 3, 4, 6]), 42, 'example 1');
+is(maxdiff([1, -2, 3, -4]), 10, 'example 2');
+is(maxdiff([-3, -1, -2, -4]), 10, 'example 3');
+is(maxdiff([10, 2, 0, 5, 1]), 50, 'example 4');
+is(maxdiff([7, 8, 9, 10, 10]), 44, 'example 5');
+
+use List::Util qw(max);
+sub maxdiff($a) {
+  my $md = 0;
+  foreach my $w (0 .. scalar @{$a} - 2) {
+    foreach my $x ($w + 1 .. scalar @{$a} - 1) {
+      foreach my $y ($w + 1 .. scalar @{$a} - 2) {
+        if ($y != $x) {
+          foreach my $z ($y + 1 .. scalar @{$a} - 1) {
+            if ($z != $x) {
+              my $v = abs($a->[$w] * $a->[$x] - $a->[$y] * $a->[$z]);
+              $md = max($md, $v);
+            }
+          }
+        }
+      }
+    }
+  }
+  $md;
+}
diff --git a/challenge-339/roger-bell-west/perl/ch-2.pl b/challenge-339/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..fd4f3c7f51
--- /dev/null
+++ b/challenge-339/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,25 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 5;
+
+is(peakpoint([-5, 1, 5, -9, 2]), 1, 'example 1');
+is(peakpoint([10, 10, 10, -25]), 30, 'example 2');
+is(peakpoint([3, -4, 2, 5, -6, 1]), 6, 'example 3');
+is(peakpoint([-1, -2, -3, -4]), 0, 'example 4');
+is(peakpoint([-10, 15, 5]), 10, 'example 5');
+
+use List::Util qw(max);
+
+sub peakpoint($a) {
+  my $h = 0;
+  my $o = 0;
+  foreach my $p (@{$a}) {
+    $h += $p;
+    $o = max($o, $h);
+  }
+  $o;
+}
diff --git a/challenge-339/roger-bell-west/postscript/ch-1.ps b/challenge-339/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..c5e860c3ad
--- /dev/null
+++ b/challenge-339/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,70 @@
+%!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 {
+    /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.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
+
+/maxdiff {
+    0 dict begin
+    /a exch def
+    0
+    0 1 a length 2 sub {
+        /w exch def
+        w 1 add 1 a length 1 sub {
+            /x exch def
+            w 1 add 1 a length 2 sub {
+                /y exch def
+                x y ne {
+                    y 1 add 1 a length 1 sub {
+                        /z exch def
+                        z x ne {
+                            a w get a x get mul a y get a z get mul sub abs
+                            max
+                        } if
+                    } for
+                } if
+            } for
+        } for
+    } for
+    end
+} bind def
+
+(maxdiff) test.start
+[5 9 3 4 6] maxdiff 42 eq test
+[1 -2 3 -4] maxdiff 10 eq test
+[-3 -1 -2 -4] maxdiff 10 eq test
+[10 2 0 5 1] maxdiff 50 eq test
+[7 8 9 10 10] maxdiff 44 eq test
+test.end
diff --git a/challenge-339/roger-bell-west/postscript/ch-2.ps b/challenge-339/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..8d066e067f
--- /dev/null
+++ b/challenge-339/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,56 @@
+%!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
+
+/peakpoint {
+    0 dict begin
+    0 exch
+    /h 0 def
+    {
+        h add /h exch def
+        h max
+    } forall
+    end
+} bind def
+
+(peakpoint) test.start
+[-5 1 5 -9 2] peakpoint 1 eq test
+[10 10 10 -25] peakpoint 30 eq test
+[3 -4 2 5 -6 1] peakpoint 6 eq test
+[-1 -2 -3 -4] peakpoint 0 eq test
+[-10 15 5] peakpoint 10 eq test
+test.end
diff --git a/challenge-339/roger-bell-west/python/ch-1.py b/challenge-339/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..558e268a00
--- /dev/null
+++ b/challenge-339/roger-bell-west/python/ch-1.py
@@ -0,0 +1,34 @@
+#! /usr/bin/python3
+
+def maxdiff(a):
+  md = 0
+  for w in range(len(a) - 1):
+    for x in range(w + 1, len(a)):
+      for y in range(w + 1, len(a) - 1):
+        if y != x:
+          for z in range(y + 1, len(a)):
+            if z != x:
+              v = abs(a[w] * a[x] - a[y] * a[z])
+              md = max(md, v)
+  return md
+
+import unittest
+
+class TestMaxdiff(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(maxdiff([5, 9, 3, 4, 6]), 42, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(maxdiff([1, -2, 3, -4]), 10, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(maxdiff([-3, -1, -2, -4]), 10, 'example 3')
+
+  def test_ex4(self):
+    self.assertEqual(maxdiff([10, 2, 0, 5, 1]), 50, 'example 4')
+
+  def test_ex5(self):
+    self.assertEqual(maxdiff([7, 8, 9, 10, 10]), 44, 'example 5')
+
+unittest.main()
diff --git a/challenge-339/roger-bell-west/python/ch-2.py b/challenge-339/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..4ac047e917
--- /dev/null
+++ b/challenge-339/roger-bell-west/python/ch-2.py
@@ -0,0 +1,30 @@
+#! /usr/bin/python3
+
+def peakpoint(a):
+  h = 0
+  o = 0
+  for p in a:
+    h += p
+    o = max(o, h)
+  return o
+
+import unittest
+
+class TestPeakpoint(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(peakpoint([-5, 1, 5, -9, 2]), 1, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(peakpoint([10, 10, 10, -25]), 30, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(peakpoint([3, -4, 2, 5, -6, 1]), 6, 'example 3')
+
+  def test_ex4(self):
+    self.assertEqual(peakpoint([-1, -2, -3, -4]), 0, 'example 4')
+
+  def test_ex5(self):
+    self.assertEqual(peakpoint([-10, 15, 5]), 10, 'example 5')
+
+unittest.main()
diff --git a/challenge-339/roger-bell-west/raku/ch-1.p6 b/challenge-339/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..a3e7819d75
--- /dev/null
+++ b/challenge-339/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,30 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 5;
+
+is(maxdiff([5, 9, 3, 4, 6]), 42, 'example 1');
+is(maxdiff([1, -2, 3, -4]), 10, 'example 2');
+is(maxdiff([-3, -1, -2, -4]), 10, 'example 3');
+is(maxdiff([10, 2, 0, 5, 1]), 50, 'example 4');
+is(maxdiff([7, 8, 9, 10, 10]), 44, 'example 5');
+
+sub maxdiff(@a) {
+    my $md = 0;
+    for 0 .. @a.elems - 2 -> $w {
+        for $w + 1 .. @a.elems - 1 -> $x {
+            for $w + 1 .. @a.elems - 2 -> $y {
+                if ($y != $x) {
+                    for $y + 1 .. @a.elems - 1 -> $z {
+                        if ($z != $x) {
+                            my $v = abs(@a[$w] * @a[$x] - @a[$y] * @a[$z]);
+                            $md = max($md, $v);
+                        }
+                    }
+                }
+            }
+        }
+    }
+    $md;
+}
diff --git a/challenge-339/roger-bell-west/raku/ch-2.p6 b/challenge-339/roger-bell-west/raku/ch-2.p6
new file mode 100755
index 0000000000..39d2d7f5e8
--- /dev/null
+++ b/challenge-339/roger-bell-west/raku/ch-2.p6
@@ -0,0 +1,21 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 5;
+
+is(peakpoint([-5, 1, 5, -9, 2]), 1, 'example 1');
+is(peakpoint([10, 10, 10, -25]), 30, 'example 2');
+is(peakpoint([3, -4, 2, 5, -6, 1]), 6, 'example 3');
+is(peakpoint([-1, -2, -3, -4]), 0, 'example 4');
+is(peakpoint([-10, 15, 5]), 10, 'example 5');
+
+sub peakpoint(@a) {
+    my $h = 0;
+    my $o = 0;
+    for @a -> $p {
+        $h += $p;
+        $o = max($o, $h);
+    }
+    $o;
+}
diff --git a/challenge-339/roger-bell-west/ruby/ch-1.rb b/challenge-339/roger-bell-west/ruby/ch-1.rb
new file mode 100755
index 0000000000..218453841d
--- /dev/null
+++ b/challenge-339/roger-bell-west/ruby/ch-1.rb
@@ -0,0 +1,46 @@
+#! /usr/bin/ruby
+
+def maxdiff(a)
+  md = 0
+  0.upto(a.length - 2) do |w|
+    (w + 1).upto(a.length - 1) do |x|
+      (w + 1).upto(a.length - 2) do |y|
+        if y != x
+          (y + 1).upto(a.length - 1) do |z|
+            if z != x
+              v = (a[w] * a[x] - a[y] * a[z]).abs
+              md = [md, v].max
+            end
+          end
+        end
+      end
+    end
+  end
+  md
+end
+
+require 'test/unit'
+
+class TestMaxdiff < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(42, maxdiff([5, 9, 3, 4, 6]))
+  end
+
+  def test_ex2
+    assert_equal(10, maxdiff([1, -2, 3, -4]))
+  end
+
+  def test_ex3
+    assert_equal(10, maxdiff([-3, -1, -2, -4]))
+  end
+
+  def test_ex4
+    assert_equal(50, maxdiff([10, 2, 0, 5, 1]))
+  end
+
+  def test_ex5
+    assert_equal(44, maxdiff([7, 8, 9, 10, 10]))
+  end
+
+end
diff --git a/challenge-339/roger-bell-west/ruby/ch-2.rb b/challenge-339/roger-bell-west/ruby/ch-2.rb
new file mode 100755
index 0000000000..c989106caf
--- /dev/null
+++ b/challenge-339/roger-bell-west/ruby/ch-2.rb
@@ -0,0 +1,37 @@
+#! /usr/bin/ruby
+
+def peakpoint(a)
+  h = 0
+  o = 0
+  a.each do |p|
+    h += p
+    o = [o, h].max
+  end
+  o
+end
+
+require 'test/unit'
+
+class TestPeakpoint < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(1, peakpoint([-5, 1, 5, -9, 2]))
+  end
+
+  def test_ex2
+    assert_equal(30, peakpoint([10, 10, 10, -25]))
+  end
+
+  def test_ex3
+    assert_equal(6, peakpoint([3, -4, 2, 5, -6, 1]))
+  end
+
+  def test_ex4
+    assert_equal(0, peakpoint([-1, -2, -3, -4]))
+  end
+
+  def test_ex5
+    assert_equal(10, peakpoint([-10, 15, 5]))
+  end
+
+end
diff --git a/challenge-339/roger-bell-west/rust/ch-1.rs b/challenge-339/roger-bell-west/rust/ch-1.rs
new file mode 100755
index 0000000000..295014543a
--- /dev/null
+++ b/challenge-339/roger-bell-west/rust/ch-1.rs
@@ -0,0 +1,46 @@
+#! /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!(maxdiff(vec![5, 9, 3, 4, 6]), 42);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(maxdiff(vec![1, -2, 3, -4]), 10);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(maxdiff(vec![-3, -1, -2, -4]), 10);
+}
+
+#[test]
+fn test_ex4() {
+    assert_eq!(maxdiff(vec![10, 2, 0, 5, 1]), 50);
+}
+
+#[test]
+fn test_ex5() {
+    assert_eq!(maxdiff(vec![7, 8, 9, 10, 10]), 44);
+}
+
+fn maxdiff(a: Vec<i32>) -> i32 {
+    let mut md = 0;
+    for w in 0..a.len() - 1 {
+        for x in w + 1..a.len() {
+            for y in w + 1..a.len() - 1 {
+                if y != x {
+                    for z in y + 1..a.len() {
+                        if z != x {
+                            let v = (a[w] * a[x] - a[y] * a[z]).abs();
+                            md = *[md, v].iter().max().unwrap();
+                        }
+                    }
+                }
+            }
+        }
+    }
+    md
+}
diff --git a/challenge-339/roger-bell-west/rust/ch-2.rs b/challenge-339/roger-bell-west/rust/ch-2.rs
new file mode 100755
index 0000000000..5d6b5a7469
--- /dev/null
+++ b/challenge-339/roger-bell-west/rust/ch-2.rs
@@ -0,0 +1,37 @@
+#! /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!(peakpoint(vec![-5, 1, 5, -9, 2]), 1);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(peakpoint(vec![10, 10, 10, -25]), 30);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(peakpoint(vec![3, -4, 2, 5, -6, 1]), 6);
+}
+
+#[test]
+fn test_ex4() {
+    assert_eq!(peakpoint(vec![-1, -2, -3, -4]), 0);
+}
+
+#[test]
+fn test_ex5() {
+    assert_eq!(peakpoint(vec![-10, 15, 5]), 10);
+}
+
+fn peakpoint(a: Vec<i32>) -> i32 {
+    let mut h = 0;
+    let mut o = 0;
+    for p in a {
+        h += p;
+        o = *[o, h].iter().max().unwrap();
+    }
+    o
+}
diff --git a/challenge-339/roger-bell-west/scala/ch-1.scala b/challenge-339/roger-bell-west/scala/ch-1.scala
new file mode 100644
index 0000000000..0d5b251c4e
--- /dev/null
+++ b/challenge-339/roger-bell-west/scala/ch-1.scala
@@ -0,0 +1,54 @@
+
+object Maxdiff {
+def maxdiff(a: List[Int]): Int = {
+    var md = 0
+    for (w <- 0 until a.size - 1) {
+        for (x <- w + 1 until a.size) {
+            for (y <- w + 1 until a.size - 1) {
+                if (y != x) {
+                    for (z <- y + 1 until a.size) {
+                        if (z != x) {
+                            val v = (a(w) * a(x) - a(y) * a(z)).abs
+                            md = List(md, v).max
+                        }
+                    }
+                }
+            }
+        }
+    }
+    md
+}
+  def main(args: Array[String]) {
+    if (maxdiff(List(5, 9, 3, 4, 6)) == 42) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    print(" ")
+    if (maxdiff(List(1, -2, 3, -4)) == 10) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    print(" ")
+    if (maxdiff(List(-3, -1, -2, -4)) == 10) {
+      print("Pass")
+    } else {