Merge pull request #8736 from Firedrake/rogerbw-challenge-235

RogerBW solutions for challenge no. 235

21 files changed, 915 insertions, 0 deletions

diff --git a/challenge-235/roger-bell-west/javascript/ch-1.js b/challenge-235/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..bbfae8ae09
--- /dev/null
+++ b/challenge-235/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,46 @@
+#! /usr/bin/node
+
+"use strict"
+
+// by VLAZ
+// https://stackoverflow.com/a/59322890
+function toWindows(inputArray, size) {
+  return Array.from(
+    {length: inputArray.length - (size - 1)}, //get the appropriate length
+    (_, index) => inputArray.slice(index, index+size) //create the windows
+  )
+}
+
+function removeone(a) {
+    let ec = 0;
+    let le = 1 + a[1] - a[0];
+    for (let s of toWindows(a, 2)) {
+        if (s[1] <= s[0]) {
+            ec++;
+            if (ec > 1 || s[0] - s[1] >= le) {
+                return false;
+            }
+        }
+        le = s[1] - s[0];
+    }
+    return true;
+}
+
+if (removeone([0, 2, 9, 4, 6])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (!removeone([5, 1, 3, 2])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (removeone([2, 2, 3])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-235/roger-bell-west/javascript/ch-2.js b/challenge-235/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..2ccebafd92
--- /dev/null
+++ b/challenge-235/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,66 @@
+#! /usr/bin/node
+
+"use strict"
+
+// by Frank Tan
+// https://stackoverflow.com/questions/38400594/javascript-deep-comparison
+function deepEqual(a,b)
+{
+    if( (typeof a == 'object' && a != null) &&
+        (typeof b == 'object' && b != null) )
+    {
+        var count = [0,0];
+        for( var key in a) count[0]++;
+        for( var key in b) count[1]++;
+        if( count[0]-count[1] != 0) {return false;}
+        for( var key in a)
+        {
+            if(!(key in b) || !deepEqual(a[key],b[key])) {return false;}
+        }
+        for( var key in b)
+        {
+            if(!(key in a) || !deepEqual(b[key],a[key])) {return false;}
+        }
+        return true;
+    }
+    else
+    {
+        return a === b;
+    }
+}
+
+function duplicatezeros(a) {
+    let out = [];
+    for (let t of a) {
+        out.push(t);
+        if (t == 0) {
+            out.push(t);
+        }
+        if (out.length >= a.length) {
+            break;
+        }
+    }
+    if (out.length > a.length) {
+        out.length = a.length;
+    }
+    return out;
+}
+
+if (deepEqual(duplicatezeros([1, 0, 2, 3, 0, 4, 5, 0]), [1, 0, 0, 2, 3, 0, 0, 4])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(duplicatezeros([1, 2, 3]), [1, 2, 3])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(duplicatezeros([0, 3, 0, 4, 5]), [0, 0, 3, 0, 0])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-235/roger-bell-west/kotlin/ch-1.kt b/challenge-235/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..fa5b415886
--- /dev/null
+++ b/challenge-235/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,37 @@
+fun removeone(a: List<Int>): Boolean {
+    var ec = 0
+    var le = 1 + a[1] - a[0]
+    for (s in a.windowed(size = 2)) {
+        if (s[1] <= s[0]) {
+            ec += 1
+            if (ec > 1 || s[0] - s[1] >= le) {
+                return false
+            }
+        }
+        le = s[1] - s[0]
+    }
+    return true
+}
+
+fun main() {
+
+    if (removeone(listOf(0, 2, 9, 4, 6))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (!removeone(listOf(5, 1, 3, 2))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (removeone(listOf(2, 2, 3))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-235/roger-bell-west/kotlin/ch-2.kt b/challenge-235/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..e340e7c6e9
--- /dev/null
+++ b/challenge-235/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,39 @@
+fun duplicatezeros(a: List<Int>): List<Int> {
+    var out = ArrayList<Int>()
+    for (t in a) {
+        out.add(t)
+        if (t == 0) {
+            out.add(t)
+        }
+        if (out.size >= a.size) {
+            break
+        }
+    }
+    if (out.size > a.size) {
+        out = ArrayList(out.dropLast(out.size - a.size))
+    }
+    return out.toList()
+}
+
+fun main() {
+
+    if (duplicatezeros(listOf(1, 0, 2, 3, 0, 4, 5, 0)) == listOf(1, 0, 0, 2, 3, 0, 0, 4)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (duplicatezeros(listOf(1, 2, 3)) == listOf(1, 2, 3)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (duplicatezeros(listOf(0, 3, 0, 4, 5)) == listOf(0, 0, 3, 0, 0)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-235/roger-bell-west/lua/ch-1.lua b/challenge-235/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..1d352b8c3d
--- /dev/null
+++ b/challenge-235/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,41 @@
+#! /usr/bin/lua
+
+function removeone(a)
+   local ec = 0
+   local le = 1 + a[2] - a[1]
+   for i, s0 in ipairs(a) do
+      if i < #a then
+         local s1 = a[i + 1]
+         if s1 <= s0 then
+            ec = ec + 1
+            if ec > 1 or (s0 - s1 >= le) then
+               return false
+            end
+         end
+         le = s1 - s0
+      end
+   end
+   return true
+end
+
+if removeone({0, 2, 9, 4, 6}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if not removeone({5, 1, 3, 2}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if removeone({2, 2, 3}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-235/roger-bell-west/lua/ch-2.lua b/challenge-235/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..c3b26f4a4c
--- /dev/null
+++ b/challenge-235/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,69 @@
+#! /usr/bin/lua
+
+-- by Michael Anderson at
+-- https://stackoverflow.com/questions/8722620/comparing-two-index-tables-by-index-value-in-lua
+-- modified by Roger
+function recursive_compare(t1,t2)
+  -- Use usual comparison first.
+  if t1==t2 then return true end
+  -- We only support non-default behavior for tables
+  if (type(t1)~="table") then return false end
+  -- They better have the same metatables
+  local mt1 = getmetatable(t1)
+  local mt2 = getmetatable(t2)
+  if( not recursive_compare(mt1,mt2) ) then return false end
+  -- Build list of all keys
+  local kk = {}
+  for k1, _ in pairs(t1) do
+     kk[k1] = true
+  end
+  for k2, _ in pairs(t2) do
+     kk[k2] = true
+  end
+  -- Check each key that exists in at least one table
+  for _, k in ipairs(kk) do
+     if (not recursive_compare(t1[k], t2[k])) then
+        return false
+     end
+  end
+  return true
+end
+
+function duplicatezeros(a)
+   local out = {}
+   for i, t in ipairs(a) do
+      table.insert(out, t)
+      if t == 0 then
+         table.insert(out, t)
+      end
+      if #out >= #a then
+         break
+      end
+   end
+   while #out > #a do
+      table.remove(out)
+   end
+   return out
+end
+
+if recursive_compare(duplicatezeros({1, 0, 2, 3, 0, 4, 5, 0}), {1, 0, 0, 2, 3, 0, 0, 4}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(duplicatezeros({1, 2, 3}), {1, 2, 3}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(duplicatezeros({0, 3, 0, 4, 5}), {0, 0, 3, 0, 0}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-235/roger-bell-west/perl/ch-1.pl b/challenge-235/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..d1e42d64a6
--- /dev/null
+++ b/challenge-235/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,27 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 3;
+
+is(removeone([0, 2, 9, 4, 6]), 1, 'example 1');
+is(removeone([5, 1, 3, 2]), 0, 'example 2');
+is(removeone([2, 2, 3]), 1, 'example 3');
+
+sub removeone($a) {
+  my $ec = 0;
+  my $le = 1 + $a->[1] - $a->[0];
+  foreach my $i (0..$#{$a}-1) {
+    my @s = ($a->[$i], $a->[$i+1]);
+    if ($s[1] <= $s[0]) {
+      $ec++;
+      if ($ec > 1 || $s[0] - $s[1] >= $le) {
+        return 0;
+      }
+    }
+    $le = $s[1] - $s[0];
+  }
+  return 1;
+}
diff --git a/challenge-235/roger-bell-west/perl/ch-2.pl b/challenge-235/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..058e919f05
--- /dev/null
+++ b/challenge-235/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,28 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 3;
+
+is_deeply(duplicatezeros([1, 0, 2, 3, 0, 4, 5, 0]), [1, 0, 0, 2, 3, 0, 0, 4], 'example 1');
+is_deeply(duplicatezeros([1, 2, 3]), [1, 2, 3], 'example 2');
+is_deeply(duplicatezeros([0, 3, 0, 4, 5]), [0, 0, 3, 0, 0], 'example 3');
+
+sub duplicatezeros($a) {
+  my @out;
+  foreach my $t (@{$a}) {
+    push @out, $t;
+    if ($t == 0) {
+      push @out, $t;
+    }
+    if ($#out >= $#{$a}) {
+      last;
+    }
+  }
+  if ($#out > $#{$a}) {
+    splice @out, scalar @{$a};
+  }
+  return \@out;
+}
diff --git a/challenge-235/roger-bell-west/postscript/ch-1.ps b/challenge-235/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..cd1c908045
--- /dev/null
+++ b/challenge-235/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,63 @@
+%!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
+
+/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
+
+/removeone {
+    0 dict begin
+    /a exch def
+    /ec 0 def
+    /lx 0 def
+    true
+    0 1 a length 2 sub {
+        a exch 2 getinterval /s exch def
+        s 1 get s 0 get le {
+            /ec ec 1 add def
+            ec 1 gt s 0 get s 1 get sub lx ge or {
+                pop false
+                exit
+            } if
+        } if
+        /lx s 1 get s 0 get sub def
+    } for
+    end
+} bind def
+
+(removeone) test.start
+[0 2 9 4 6] removeone test
+[5 1 3 2] removeone not test
+[2 2 2] removeone not test
+test.end
diff --git a/challenge-235/roger-bell-west/postscript/ch-2.ps b/challenge-235/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..aa8499f97a
--- /dev/null
+++ b/challenge-235/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,120 @@
+%!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
+
+/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
+
+
+% end included library code
+
+/duplicatezeros {
+    0 dict begin
+    /a exch def
+    /out 
+    [
+        a {
+            dup
+            0 eq {
+                dup
+            } if
+        } forall
+    ] def
+    out length a length gt {
+        /out out 0 a length getinterval def
+    } if
+    out
+    end
+} bind def
+
+(duplicatezeros) test.start
+[1 0 2 3 0 4 5 0] duplicatezeros [1 0 0 2 3 0 0 4] deepeq test
+[1 2 3] duplicatezeros [1 2 3] deepeq test
+[0 3 0 4 5] duplicatezeros [0 0 3 0 0] deepeq test
+test.end
diff --git a/challenge-235/roger-bell-west/python/ch-1.py b/challenge-235/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..3b060b3899
--- /dev/null
+++ b/challenge-235/roger-bell-west/python/ch-1.py
@@ -0,0 +1,29 @@
+#! /usr/bin/python3
+
+from itertools import pairwise
+
+def removeone(a):
+  ec = 0
+  le = 1 + a[1] - a[0]
+  for s in pairwise(a):
+    if s[1] <= s[0]:
+      ec += 1
+      if ec > 1 or s[0] - s[1] >= le:
+        return False
+    le = s[1] - s[0]
+  return True
+
+import unittest
+
+class TestRemoveone(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(removeone([0, 2, 9, 4, 6]), True, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(removeone([5, 1, 3, 2]), False, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(removeone([2, 2, 3]), True, 'example 3')
+
+unittest.main()
diff --git a/challenge-235/roger-bell-west/python/ch-2.py b/challenge-235/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..e5f1bc39fc
--- /dev/null
+++ b/challenge-235/roger-bell-west/python/ch-2.py
@@ -0,0 +1,29 @@
+#! /usr/bin/python3
+
+def duplicatezeros(a):
+  out = []
+  for t in a:
+    out.append(t)
+    if t == 0:
+      out.append(t)
+    if len(out) >= len(a):
+      break
+  if len(out) > len(a):
+    out = out[0:len(a)]
+  return out
+      
+
+import unittest
+
+class TestDuplicatezeros(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(duplicatezeros([1, 0, 2, 3, 0, 4, 5, 0]), [1, 0, 0, 2, 3, 0, 0, 4], 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(duplicatezeros([1, 2, 3]), [1, 2, 3], 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(duplicatezeros([0, 3, 0, 4, 5]), [0, 0, 3, 0, 0], 'example 3')
+
+unittest.main()
diff --git a/challenge-235/roger-bell-west/raku/ch-1.p6 b/challenge-235/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..0f657a401d
--- /dev/null
+++ b/challenge-235/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,24 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 3;
+
+is(removeone([0, 2, 9, 4, 6]), True, 'example 1');
+is(removeone([5, 1, 3, 2]), False, 'example 2');
+is(removeone([2, 2, 3]), True, 'example 3');
+
+sub removeone(@a) {
+    my $ec = 0;
+    my $le = 1 + @a[1] - @a[0];
+    for @a.rotor(2 => -1) -> @s {
+        if (@s[1] <= @s[0]) {
+            $ec++;
+            if ($ec > 1 || @s[0] - @s[1] >= $le) {
+                return False;
+            }
+        }
+        $le = @s[1] - @s[0];
+    }
+    return True;
+}
diff --git a/challenge-235/roger-bell-west/raku/ch-2.p6 b/challenge-235/roger-bell-west/raku/ch-2.p6
new file mode 100755
index 0000000000..fa555a4e79
--- /dev/null
+++ b/challenge-235/roger-bell-west/raku/ch-2.p6
@@ -0,0 +1,26 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 3;
+
+is-deeply(duplicatezeros([1, 0, 2, 3, 0, 4, 5, 0]), [1, 0, 0, 2, 3, 0, 0, 4], 'example 1');
+is-deeply(duplicatezeros([1, 2, 3]), [1, 2, 3], 'example 2');
+is-deeply(duplicatezeros([0, 3, 0, 4, 5]), [0, 0, 3, 0, 0], 'example 3');
+
+sub duplicatezeros(@a) {
+    my @out;
+    for @a -> $t {
+        @out.push($t);
+        if ($t == 0) {
+            @out.push($t)
+        }
+        if (@out.elems >= @a.elems) {
+            last;
+        }
+    }
+    if (@out.elems > @a.elems) {
+        @out.splice(@a.elems);
+    }
+    return @out;
+}
diff --git a/challenge-235/roger-bell-west/ruby/ch-1.rb b/challenge-235/roger-bell-west/ruby/ch-1.rb
new file mode 100755
index 0000000000..b14816ca1f
--- /dev/null
+++ b/challenge-235/roger-bell-west/ruby/ch-1.rb
@@ -0,0 +1,34 @@
+#! /usr/bin/ruby
+
+def removeone(a)
+  ec = 0
+  le = 1 + a[1] - a[0]
+  a.each_cons(2) do |s|
+    if s[1] <= s[0] then
+      ec += 1
+      if ec > 1 || s[0] - s[1] >= le then
+        return false
+      end
+    end
+    le = s[1] - s[0]
+  end
+  return true
+end
+
+require 'test/unit'
+
+class TestRemoveone < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(true, removeone([0, 2, 9, 4, 6]))
+  end
+
+  def test_ex2
+    assert_equal(false, removeone([5, 1, 3, 2]))
+  end
+
+  def test_ex3
+    assert_equal(true, removeone([2, 2, 3]))
+  end
+
+end
diff --git a/challenge-235/roger-bell-west/ruby/ch-2.rb b/challenge-235/roger-bell-west/ruby/ch-2.rb
new file mode 100755
index 0000000000..7c3f88b4fd
--- /dev/null
+++ b/challenge-235/roger-bell-west/ruby/ch-2.rb
@@ -0,0 +1,33 @@
+#! /usr/bin/ruby
+
+def duplicatezeros(a)
+  out = []
+  a.each do |t|
+    out.push(t)
+    if t == 0 then
+      out.push(t)
+    end
+    if out.length >= a.length then
+      break
+    end
+  end
+  return out[0, a.length]
+end
+
+require 'test/unit'
+
+class TestDuplicatezeros < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal([1, 0, 0, 2, 3, 0, 0, 4], duplicatezeros([1, 0, 2, 3, 0, 4, 5, 0]))
+  end
+
+  def test_ex2
+    assert_equal([1, 2, 3], duplicatezeros([1, 2, 3]))
+  end
+
+  def test_ex3
+    assert_equal([0, 0, 3, 0, 0], duplicatezeros([0, 3, 0, 4, 5]))
+  end
+
+end
diff --git a/challenge-235/roger-bell-west/rust/ch-1.rs b/challenge-235/roger-bell-west/rust/ch-1.rs
new file mode 100755
index 0000000000..cfa39d5082
--- /dev/null
+++ b/challenge-235/roger-bell-west/rust/ch-1.rs
@@ -0,0 +1,32 @@
+#! /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!(removeone(vec![0, 2, 9, 4, 6]), true);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(removeone(vec![5, 1, 3, 2]), false);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(removeone(vec![2, 2, 3]), true);
+}
+
+fn removeone(a: Vec<i64>) -> bool {
+    let mut ec = 0u32;
+    let mut le = 1 + a[1] - a[0];
+    for s in a.windows(2) {
+        if s[1] <= s[0] {
+            ec += 1;
+            if ec > 1 || s[0] - s[1] >= le {
+                return false;
+            }
+        }
+        le = s[1] - s[0];
+    }
+    true
+}
diff --git a/challenge-235/roger-bell-west/rust/ch-2.rs b/challenge-235/roger-bell-west/rust/ch-2.rs
new file mode 100755
index 0000000000..85048d5ed9
--- /dev/null
+++ b/challenge-235/roger-bell-west/rust/ch-2.rs
@@ -0,0 +1,35 @@
+#! /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!(
+        duplicatezeros(vec![1, 0, 2, 3, 0, 4, 5, 0]),
+        vec![1, 0, 0, 2, 3, 0, 0, 4]
+    );
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(duplicatezeros(vec![1, 2, 3]), vec![1, 2, 3]);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(duplicatezeros(vec![0, 3, 0, 4, 5]), vec![0, 0, 3, 0, 0]);
+}
+
+fn duplicatezeros(a: Vec<u32>) -> Vec<u32> {
+    let mut out = Vec::new();
+    for t in &a {
+        out.push(*t);
+        if *t == 0 {
+            out.push(*t);
+        }
+        if out.len() >= a.len() {
+            break;
+        }
+    }
+    out.resize(a.len(), out[0]);
+    out
+}
diff --git a/challenge-235/roger-bell-west/scala/ch-1.scala b/challenge-235/roger-bell-west/scala/ch-1.scala
new file mode 100644
index 0000000000..b244ec15ec
--- /dev/null
+++ b/challenge-235/roger-bell-west/scala/ch-1.scala
@@ -0,0 +1,38 @@
+object Removeone {
+  def removeone(a: List[Int]): Boolean = {
+    var ec = 0
+    var le = 1 + a(1) - a(0)
+    for (s <- a.sliding(2)) {
+      if (s(1) <= s(0)) {
+        ec += 1
+        if (ec > 1 || s(0) - s(1) >= le) {
+          return false
+        }
+      }
+      le = s(1) - s(0)
+    }
+    return true
+  }
+
+  def main(args: Array[String]) {
+      if (removeone(List(0, 2, 9, 4, 6))) {
+          print("Pass")
+      } else {
+          print("Fail")
+      }
+      print(" ")
+      if (!removeone(List(5, 1, 3, 2))) {
+          print("Pass")
+      } else {
+          print("Fail")
+      }
+      print(" ")
+      if (removeone(List(2, 2, 3))) {
+          print("Pass")
+      } else {
+          print("Fail")
+      }
+      println("")
+
+  }
+}
diff --git a/challenge-235/roger-bell-west/scala/ch-2.scala b/challenge-235/roger-bell-west/scala/ch-2.scala
new file mode 100755
index 0000000000..2cebbe97ad
--- /dev/null
+++ b/challenge-235/roger-bell-west/scala/ch-2.scala
@@ -0,0 +1,38 @@
+import scala.collection.mutable.ListBuffer
+
+object Duplicatezeros {
+  def duplicatezeros(a: List[Int]): List[Int] = {
+    var out = new ListBuffer[Int]
+    for (t <- a) {
+      out += t
+      if (t == 0) {
+        out += t
+      }
+    }
+    if (out.length > a.length) {
+      out = out.dropRight(out.length - a.length)
+    }
+    return out.toList
+  }
+
+  def main(args: Array[String]) {
+    if (duplicatezeros(List(1, 0, 2, 3, 0, 4, 5, 0)) == List(1, 0, 0, 2, 3, 0, 0, 4)) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    print(" ")
+    if (duplicatezeros(List(1, 2, 3)) == List(1, 2, 3)) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    print(" ")
+    if (duplicatezeros(List(0, 3, 0, 4, 5)) == List(0, 0, 3, 0, 0)) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    println("")
+  }
+}
diff --git a/challenge-235/roger-bell-west/tests.yaml b/challenge-235/roger-bell-west/tests.yaml
new file mode 100644
index 0000000000..ad55ebfae6
--- /dev/null
+++ b/challenge-235/roger-bell-west/tests.yaml
@@ -0,0 +1,61 @@
+---
+ch-1:
+  - function: removeone
+    arguments:
+      - 0
+      - 2
+      - 9
+      - 4
+      - 6
+    result: true
+  - arguments:
+      - 5
+      - 1
+      - 3
+      - 2
+    result: false
+  - arguments:
+      - 2
+      - 2
+      - 3
+    result: true
+ch-2:
+  - function: duplicatezeros
+    arguments:
+      - 1
+      - 0
+      - 2
+      - 3
+      - 0
+      - 4
+      - 5
+      - 0
+    result:
+      - 1
+      - 0
+      - 0
+      - 2
+      - 3
+      - 0
+      - 0
+      - 4
+  - arguments:
+      - 1
+      - 2
+      - 3
+    result:
+      - 1
+      - 2
+      - 3
+  - arguments:
+      - 0
+      - 3
+      - 0
+