Merge pull request #8722 from Firedrake/rogerbw-challenge-234

Rogerbw challenge 234

19 files changed, 1225 insertions, 0 deletions

diff --git a/challenge-234/roger-bell-west/javascript/ch-1.js b/challenge-234/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..de9c406186
--- /dev/null
+++ b/challenge-234/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,91 @@
+#! /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 commoncharacters(a) {
+    let ac = [];
+    for (let w of a) {
+        let h = new Map();
+        for (let c of w.split("")) {
+            if (h.has(c)) {
+                h.set(c, h.get(c) + 1);
+            } else {
+                h.set(c, 1);
+            }
+        }
+        ac.push(h);
+    }
+    let vc = new Map();
+    for (let i = 0; i < ac.length; i++) {
+        if (i == 0) {
+            for (let c of ac[i].keys()) {
+                vc.set(c, ac[i].get(c));
+            }
+        } else {
+            for (let c of vc.keys()) {
+                if (ac[i].has(c)) {
+                    vc.set(c, Math.min(vc.get(c), ac[i].get(c)));
+                } else {
+                    vc.delete(c);
+                }
+            }
+        }
+    }
+    let out = [];
+    for (let c of a[0].split("")) {
+        if (vc.has(c)) {
+            out.push(c);
+            vc.set(c, vc.get(c) - 1);
+            if (vc.get(c) == 0) {
+                vc.delete(c);
+            }
+        }
+    }
+    return out;
+}
+
+if (deepEqual(commoncharacters(['java', 'javascript', 'julia']), ['j', 'a'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(commoncharacters(['bella', 'label', 'roller']), ['e', 'l', 'l'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(commoncharacters(['cool', 'lock', 'cook']), ['c', 'o'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-234/roger-bell-west/javascript/ch-2.js b/challenge-234/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..a463ef13ac
--- /dev/null
+++ b/challenge-234/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,69 @@
+#! /usr/bin/node
+
+"use strict"
+
+function combinations(arr, k) {
+    let c = [];
+    for (let i = 0; i < k; i++) {
+        c.push(i);
+    }
+    c.push(arr.length);
+    c.push(0);
+    let out = [];
+    while (true) {
+        let inner = [];
+        for (let i = k-1; i >= 0; i--) {
+            inner.push(arr[c[i]]);
+        }
+        out.push(inner);
+        let j = 0;
+        while (c[j] + 1 == c[j + 1]) {
+            c[j] = j;
+            j += 1;
+        }
+        if (j >= k) {
+            break;
+        }
+        c[j] += 1;
+    }
+    return out;
+}
+
+function unequaltriplets(utl) {
+    let utc = new Map();
+    for (let n of utl) {
+        if (utc.has(n)) {
+            utc.set(n, utc.get(n) + 1);
+        } else {
+            utc.set(n, 1);
+        }
+    }
+    const kl = Array.from(utc.keys());
+    if (kl.length < 3) {
+        return 0;
+    }
+    let out = 0;
+    for (let c of combinations(kl, 3)) {
+        out += utc.get(c[0]) * utc.get(c[1]) * utc.get(c[2]);
+    }
+    return out;
+}
+
+if (unequaltriplets([4, 4, 2, 4, 3]) == 3) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (unequaltriplets([1, 1, 1, 1, 1]) == 0) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (unequaltriplets([4, 7, 1, 10, 7, 4, 1, 1]) == 28) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-234/roger-bell-west/kotlin/ch-1.kt b/challenge-234/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..f31a5d0c61
--- /dev/null
+++ b/challenge-234/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,62 @@
+import kotlin.math.min
+
+fun commoncharacters(a: List<String>): List<Char> {
+    var ac = ArrayList<Map<Char, Int>>()
+    for (w in a) {
+        var h = mutableMapOf<Char, Int>().withDefault({0})
+        for (c in w.toCharArray()) {
+            h.set(c, h.getValue(c) + 1)
+        }
+        ac.add(h)
+    }
+    var vc = mutableMapOf<Char, Int>()
+    for (i in 0 .. ac.size - 1) {
+        if (i == 0) {
+            for (c in ac[i].keys) {
+                vc.set(c, ac[i].get(c)!!)
+            }
+        } else {
+            for (c in vc.keys.toList()) {
+                if (ac[i].contains(c)) {
+                    vc.set(c, min(vc.get(c)!!, ac[i].get(c)!!))
+                } else {
+                    vc.remove(c)
+                }
+            }
+        }
+    }
+    var out = ArrayList<Char>()
+    for (c in a[0].toCharArray()) {
+        if (vc.contains(c)) {
+            out.add(c)
+            vc.set(c, vc.get(c)!! - 1)
+            if (vc.get(c)!! == 0) {
+                vc.remove(c)
+            }
+        }
+    }
+    return out.toList()
+}
+
+fun main() {
+
+    if (commoncharacters(listOf("java", "javascript", "julia")) == listOf('j', 'a')) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (commoncharacters(listOf("bella", "label", "roller")) == listOf('e', 'l', 'l')) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (commoncharacters(listOf("cool", "lock", "cook")) == listOf('c', 'o')) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-234/roger-bell-west/kotlin/ch-2.kt b/challenge-234/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..28a9f3a683
--- /dev/null
+++ b/challenge-234/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,65 @@
+fun combinations(arr: List<Int>, k: Int): List<List<Int>> {
+    var c = ArrayList<Int>()
+    for (i in 0 .. k-1) {
+        c.add(i)
+    }
+    c.add(arr.size)
+    c.add(0)
+    var out = ArrayList<List<Int>>()
+    while (true) {
+        var inner = ArrayList<Int>()
+        for (i in k-1 downTo 0) {
+            inner.add(arr[c[i]])
+        }
+        out.add(inner.toList())
+        var j = 0
+        while (c[j] + 1 == c[j + 1]) {
+            c[j] = j
+            j += 1
+        }
+        if (j >= k) {
+            break
+        }
+        c[j] += 1
+    }
+    return out.toList();
+}
+
+fun unequaltriplets(utl: List<Int>): Int {
+    var utc = mutableMapOf<Int, Int>().withDefault({0})
+    for (n in utl) {
+        utc.set(n, utc.getValue(n) + 1);
+    }
+    val kl = utc.keys.toList()
+    if (kl.size < 3) {
+        return 0
+    }
+    var out = 0
+    for (c in combinations(kl, 3)) {
+        out += utc.getValue(c[0]) * utc.getValue(c[1]) * utc.getValue(c[2]);
+    }
+    return out
+}
+
+fun main() {
+
+    if (unequaltriplets(listOf(4, 4, 2, 4, 3)) == 3) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (unequaltriplets(listOf(1, 1, 1, 1, 1)) == 0) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (unequaltriplets(listOf(4, 7, 1, 10, 7, 4, 1, 1)) == 28) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-234/roger-bell-west/lua/ch-1.lua b/challenge-234/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..09679319d9
--- /dev/null
+++ b/challenge-234/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,112 @@
+#! /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 split(t)
+   local cl = {}
+   string.gsub(t,
+               "(.)",
+               function(c)
+                  table.insert(cl, c)
+               end
+   )
+   return cl
+end
+
+function deepcopy(src)
+   local dst = {}
+   for k, v in pairs(src) do
+      if type(v) == "table" then
+         v = deepcopy(v)
+      end
+      dst[k] = v
+   end
+   return dst
+end
+
+function commoncharacters(a)
+   local ac = {}
+   for _i, w in ipairs(a) do
+      local h = {}
+      for _j, c in ipairs(split(w)) do
+         if h[c] == nil then
+            h[c] = 1
+         else
+            h[c] = h[c] + 1
+         end
+      end
+      table.insert(ac, h)
+   end
+   local vc = deepcopy(ac[1])
+   for i, aa in ipairs(ac) do
+      if i > 1 then
+         for c, ct in pairs(vc) do
+            if aa[c] == nil then
+               vc[c] = nil
+            elseif aa[c] < vc[c] then
+               vc[c] = aa[c]
+            end
+         end
+      end
+   end
+   local out = {}
+   for _, c in ipairs(split(a[1])) do
+      if vc[c] ~= nil then
+         table.insert(out, c)
+         vc[c] = vc[c] - 1
+         if vc[c] == 0 then
+            vc[c] = nil
+         end
+      end
+   end
+   return out
+end
+
+if recursive_compare(commoncharacters({"java", "javascript", "julia"}), {"j", "a"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(commoncharacters({"bella", "label", "roller"}), {"e", "l", "l"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(commoncharacters({"cool", "lock", "cook"}), {"c", "o"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-234/roger-bell-west/lua/ch-2.lua b/challenge-234/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..6a268448b4
--- /dev/null
+++ b/challenge-234/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,78 @@
+#! /usr/bin/lua
+
+function keys(t)
+   local a = {}
+   for k, v in pairs(t) do
+      table.insert(a, k)
+   end
+   return a
+end
+
+function combinations(arr, k)
+   local c = {}
+   for i = 1, k do
+      table.insert(c, i)
+   end
+   table.insert(c, #arr + 1)
+   table.insert(c, 0)
+   local out = {}
+   while true do
+      local inner = {}
+      for i = k, 1, -1 do
+         table.insert(inner, arr[c[i]])
+      end
+      table.insert(out, inner)
+      local j = 1
+      while c[j] + 1 == c[j + 1] do
+         c[j] = j
+         j = j + 1
+      end
+      if j > k then
+         break
+      end
+      c[j] = c[j] + 1
+   end
+   return ipairs(out)
+end
+
+function unequaltriplets(utl)
+   local utc = {}
+   for _i, n in ipairs(utl) do
+      if utc[n] == nil then
+         utc[n] = 1
+      else
+         utc[n] = utc[n] + 1
+      end
+   end
+   local kl = keys(utc)
+   if #kl < 3 then
+      return 0
+   end
+   local out = 0
+   for _, c in combinations(kl, 3) do
+      out = out + utc[c[1]] * utc[c[2]] * utc[c[3]]
+   end
+   return out
+end
+
+if unequaltriplets({4, 4, 2, 4, 3}) == 3 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if unequaltriplets({1, 1, 1, 1, 1}) == 0 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if unequaltriplets({4, 7, 1, 10, 7, 4, 1, 1}) == 28 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-234/roger-bell-west/perl/ch-1.pl b/challenge-234/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..0e8095b393
--- /dev/null
+++ b/challenge-234/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,44 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use List::Util qw(min);
+use Test::More tests => 3;
+
+is_deeply(commoncharacters(['java', 'javascript', 'julia']), ['j', 'a'], 'example 1');
+is_deeply(commoncharacters(['bella', 'label', 'roller']), ['e', 'l', 'l'], 'example 2');
+is_deeply(commoncharacters(['cool', 'lock', 'cook']), ['c', 'o'], 'example 3');
+
+sub commoncharacters ($a) {
+  my @ac;
+  foreach my $w (@{$a}) {
+    my %h;
+    foreach my $c (split '', $w) {
+      $h{$c}++;
+    }
+    push @ac, \%h;
+  }
+  my %vc = %{$ac[0]};
+  foreach my $aa (@ac) {
+    foreach my $c (keys %vc) {
+      if (exists $aa->{$c}) {
+        $vc{$c} = min($vc{$c}, $aa->{$c});
+      } else {
+        delete $vc{$c};
+      }
+    }
+  }
+  my @out;
+  foreach my $c (split '', $a->[0]) {
+    if (exists $vc{$c}) {
+      push @out, $c;
+      $vc{$c}--;
+      if ($vc{$c} == 0) {
+        delete $vc{$c};
+      }
+    }
+  }
+  return \@out;
+}
diff --git a/challenge-234/roger-bell-west/perl/ch-2.pl b/challenge-234/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..a7b9a35386
--- /dev/null
+++ b/challenge-234/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;
+use Algorithm::Combinatorics qw(combinations);
+
+is(unequaltriplets([4, 4, 2, 4, 3]), 3, 'example 1');
+is(unequaltriplets([1, 1, 1, 1, 1]), 0, 'example 2');
+is(unequaltriplets([4, 7, 1, 10, 7, 4, 1, 1]), 28, 'example 3');
+
+sub unequaltriplets($utl) {
+  my %utc;
+  foreach my $n (@{$utl}) {
+    $utc{$n}++;
+  }
+  my @kl = keys %utc;
+  if (scalar @kl < 3) {
+    return 0;
+  }
+  my $out = 0;
+  foreach my $c (combinations(\@kl, 3)) {
+    $out += $utc{$c->[0]} * $utc{$c->[1]} * $utc{$c->[2]};
+  }
+  return $out;
+}
diff --git a/challenge-234/roger-bell-west/postscript/ch-1.ps b/challenge-234/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..8f084f182b
--- /dev/null
+++ b/challenge-234/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,204 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/s2a {
+    [ exch { } forall ]
+} bind def
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+/map { % array proc -> array
+    2 dict begin
+    /p exch def
+    [ exch
+      {
+          p
+      } forall
+    ]
+    end
+} bind def
+
+/dget {
+    3 1 roll
+    2 copy
+    known {
+        get exch pop
+    } {
+        pop pop
+    } 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
+
+/keys { % dict -> array of dict keys
+    [ exch
+      {
+          pop
+      } forall
+    ]
+} bind def
+
+
+/deepcopy {
+    2 dict begin
+    /a exch def
+    a type /dicttype eq {
+        <<
+            a keys {
+                /k exch def
+                k
+                a k get deepcopy
+            } forall
+        >>
+    } {
+        a type /arraytype eq {
+            [
+                a {
+                    deepcopy
+                } forall
+            ]
+        } {
+            a type /stringtype eq {
+                a dup length string cvs
+            } {
+                a
+            } ifelse
+        } ifelse
+    } 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
+
+/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
+
+/commoncharacters {
+    0 dict begin
+    /a exch def
+    [
+        a {
+            /h 0 dict def
+            s2a {
+                /c exch def
+                h c 2 copy 0 dget 1 add put
+            } forall
+            h
+        } forall
+    ] /ac exch bind def
+    /vc ac 0 get deepcopy def
+    ac {
+        /aa exch def
+        vc keys {
+            /c exch def
+            aa c known {
+                vc c 2 copy get aa c get min put
+            } {
+                vc c undef
+            } ifelse
+        } forall
+    } forall
+    [
+        a 0 get s2a {
+            /c exch def
+            vc c known {
+                c
+                vc c 2 copy get 1 sub put
+                vc c get 0 eq {
+                    vc c undef
+                } if
+            } if
+        } forall
+    ] { 1 string dup 3 2 roll 0 exch put } map
+    end
+} bind def
+
+(commoncharacters) test.start
+[(java) (javascript) (julia)] commoncharacters [(j) (a)] deepeq test
+[(bella) (label) (roller)] commoncharacters [(e) (l) (l)] deepeq test
+[(cool) (lock) (cook)] commoncharacters [(c) (o)] deepeq test
+test.end
diff --git a/challenge-234/roger-bell-west/postscript/ch-2.ps b/challenge-234/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..4d4c35815b
--- /dev/null
+++ b/challenge-234/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,138 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/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
+
+/combinations {
+    4 dict begin
+    /k exch def
+    /arr exch def
+    /c [
+        0 1 k 1 sub { } for
+        arr length
+        0
+    ] def
+    [
+        {
+            [
+                k 1 sub -1 0 {
+                    c exch get arr exch get
+                } for
+            ]
+            /j 0 def
+            {
+                c j get 1 add c j 1 add get ne {
+                    exit
+                } if
+                c j j put
+                /j j 1 add def
+            } loop
+            j k ge {
+                exit
+            } if
+            c j c j get 1 add put
+        } loop
+    ]
+    end
+} bind def
+
+/keys { % dict -> array of dict keys
+    [ exch
+      {
+          pop
+      } forall
+    ]
+} 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
+
+/dget {
+    3 1 roll
+    2 copy
+    known {
+        get exch pop
+    } {
+        pop pop
+    } ifelse
+} 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
+
+/map { % array proc -> array
+    2 dict begin
+    /p exch def
+    [ exch
+      {
+          p
+      } forall
+    ]
+    end
+} bind def
+
+
+% end included library code
+
+/unequaltriplets {
+    0 dict begin
+    /utc 0 dict def
+    {
+        /n exch def
+        utc n 2 copy 0 dget 1 add put
+    } forall
+    /kl utc keys def
+    kl length 3 lt {
+        0
+    } {
+        0
+        kl 3 combinations {
+            /c exch def
+            [ 0 1 2 { } for ] { c exch get utc exch get } map
+            { mul } reduce add
+        } forall
+    } ifelse
+    end
+} bind def
+
+(unequaltriplets) test.start
+[4 4 2 4 3] unequaltriplets 3 eq test
+[1 1 1 1 1] unequaltriplets 0 eq test
+[4 7 1 10 7 4 1 1] unequaltriplets 28 eq test
+test.end
diff --git a/challenge-234/roger-bell-west/python/ch-1.py b/challenge-234/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..2c00ffcd6c
--- /dev/null
+++ b/challenge-234/roger-bell-west/python/ch-1.py
@@ -0,0 +1,41 @@
+#! /usr/bin/python3
+
+from collections import defaultdict
+
+def commoncharacters(a):
+  ac = []
+  for w in a:
+    h = defaultdict(lambda: 0)
+    for c in w:
+      h[c] += 1
+    ac.append(h)
+  vc = ac[0]
+  for aa in ac[1:]:
+    for c in list(vc.keys()):
+      if c in aa:
+        vc[c] = min(vc[c], aa[c])
+      else:
+        del vc[c]
+  out = []
+  for c in a[0]:
+    if c in vc:
+      out.append(c)
+      vc[c] -= 1
+      if vc[c] == 0:
+        del vc[c]
+  return out
+
+import unittest
+
+class TestCommoncharacters(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(commoncharacters(["java", "javascript", "julia"]), ["j", "a"], 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(commoncharacters(["bella", "label", "roller"]), ["e", "l", "l"], 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(commoncharacters(["cool", "lock", "cook"]), ["c", "o"], 'example 3')
+
+unittest.main()
diff --git a/challenge-234/roger-bell-west/python/ch-2.py b/challenge-234/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..dc14ee61c3
--- /dev/null
+++ b/challenge-234/roger-bell-west/python/ch-2.py
@@ -0,0 +1,31 @@
+#! /usr/bin/python3
+
+from collections import defaultdict
+from itertools import combinations
+
+def unequaltriplets(a):
+  utc = defaultdict(lambda: 0)
+  for n in a:
+    utc[n] += 1
+  kl = list(utc.keys())
+  if len(kl) < 3:
+    return 0
+  out = 0
+  for c in combinations(kl, 3):
+    out += utc[c[0]] * utc[c[1]] * utc[c[2]]
+  return out
+  
+import unittest
+
+class TestUnequaltriplets(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(unequaltriplets([4, 4, 2, 4, 3]), 3, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(unequaltriplets([1, 1, 1, 1, 1]), 0, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(unequaltriplets([4, 7, 1, 10, 7, 4, 1, 1]), 28, 'example 3')
+
+unittest.main()
diff --git a/challenge-234/roger-bell-west/raku/ch-1.p6 b/challenge-234/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..cacfe75582
--- /dev/null
+++ b/challenge-234/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,34 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 3;
+
+is-deeply(commoncharacters(['java', 'javascript', 'julia']), ['j', 'a'], 'example 1');
+is-deeply(commoncharacters(['bella', 'label', 'roller']), ['e', 'l', 'l'], 'example 2');
+is-deeply(commoncharacters(['cool', 'lock', 'cook']), ['c', 'o'], 'example 3');
+
+sub commoncharacters (@a) {
+    my @ac;
+    for @a -> $w {
+        @ac.push($w.comb.Bag);
+    }
+    my %vc = BagHash(@ac[0]);
+    for @ac.skip(1) -> $aa {
+        for keys %vc -> $c {
+            if ($aa{$c}:exists) {
+                %vc{$c} = min(%vc{$c}, $aa{$c});
+            } else {
+                %vc{$c}:delete;
+            }
+        }<