RogerBW solutions for challenge no. 216

19 files changed, 1451 insertions, 0 deletions

diff --git a/challenge-216/roger-bell-west/javascript/ch-1.js b/challenge-216/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..cfebc90c62
--- /dev/null
+++ b/challenge-216/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,76 @@
+#! /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 word2set(word) {
+    let r = new Set();
+    for (let c of word.toLowerCase()) {
+        if (c >= 'a' && c <= 'z') {
+            r.add(c);
+        }
+    }
+    return r
+}
+
+function registrationnumber(words, reg) {
+    let out = [];
+    for (let w of words) {
+        let ss = word2set(reg);
+        for (let char of word2set(w)) {
+            if (ss.has(char)) {
+                ss.delete(char);
+                if (ss.size == 0) {
+                    out.push(w);
+                    break;
+                }
+            }
+        }
+    }
+    return out;
+}
+
+if (deepEqual(registrationnumber(['abc', 'abcd', 'bcd'], 'AB1 2CD'), ['abcd'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(registrationnumber(['job', 'james', 'bjorg'], '007 JB'), ['job', 'bjorg'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(registrationnumber(['crack', 'road', 'rac'], 'C7 RA2'), ['crack', 'rac'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-216/roger-bell-west/javascript/ch-2.js b/challenge-216/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..aa8c83d535
--- /dev/null
+++ b/challenge-216/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,91 @@
+#! /usr/bin/node
+
+"use strict"
+
+function word2map(word) {
+    let m = new Map();
+    for (let c of word.toLowerCase()) {
+        if (m.has(c)) {
+            m.set(c, m.get(c) + 1);
+        } else {
+            m.set(c, 1);
+        }
+    }
+    return m;
+}
+
+function shallowclonemap(m) {
+    let mm = new Map();
+    for (let k of m.keys()) {
+        mm.set(k, m.get(k));
+    }
+    return mm;
+}
+
+function wordstickers(stickers, word) {
+    const w = word2map(word);
+    let t = shallowclonemap(w);
+    let stick = [];
+    for (let s of stickers) {
+        let f = word2map(s);
+        for (let c of f.keys()) {
+            t.delete(c);
+        }
+        stick.push(f);
+    }
+    if (t.size > 0) {
+        return 0;
+    }
+    let stack = [[w, 0]];
+    while (stack.length > 0) {
+        const st = stack.shift();
+        if (st[0].size == 0) {
+            return st[1];
+        } else {
+            const n = st[1] + 1;
+            for (let sti of stick) {
+                let sp = shallowclonemap(st[0]);
+                let v = false;
+                for (let l of sti.keys()) {
+                    if (sp.has(l)) {
+                        v = true;
+                        const p = sp.get(l) - sti.get(l);
+                        if (p > 0) {
+                            sp.set(l, p);
+                        } else {
+                            sp.delete(l);
+                        }
+                    }
+                }
+                if (v) {
+                    stack.push([sp, n]);
+                }
+            }
+        }
+    }
+}
+
+if (wordstickers(['perl', 'raku', 'python'], 'peon') == 2) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (wordstickers(['love', 'hate', 'angry'], 'goat') == 3) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (wordstickers(['come', 'nation', 'delta'], 'accomodation') == 4) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (wordstickers(['come', 'country', 'delta'], 'accomodation') == 0) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-216/roger-bell-west/kotlin/ch-1.kt b/challenge-216/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..5f0333a7ff
--- /dev/null
+++ b/challenge-216/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,49 @@
+fun word2set(word: String): MutableSet<Char> {
+    var r = mutableSetOf<Char>()
+    for (c in word.lowercase()) {
+        if (c >= 'a' && c <= 'z') {
+            r.add(c)
+        }
+    }
+    return r
+}
+
+fun registrationnumber(words: List<String>, reg: String): List<String> {
+    var out = ArrayList<String>()
+    for (w in words) {
+        var ss = word2set(reg);
+        for (char in word2set(w)) {
+            if (ss.contains(char)) {
+                ss.remove(char);
+                if (ss.size == 0) {
+                    out.add(w)
+                    break
+                }
+            }
+        }
+    }
+    return out
+}
+
+fun main() {
+
+    if (registrationnumber(listOf("abc", "abcd", "bcd"), "AB1 2CD") == listOf("abcd")) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (registrationnumber(listOf("job", "james", "bjorg"), "007 JB") == listOf("job", "bjorg")) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (registrationnumber(listOf("crack", "road", "rac"), "C7 RA2") == listOf("crack", "rac")) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-216/roger-bell-west/kotlin/ch-2.kt b/challenge-216/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..bd624f6ee0
--- /dev/null
+++ b/challenge-216/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,92 @@
+fun word2map(word: String): Map<Char, Int> {
+    var m = mutableMapOf<Char, Int>()
+    for (c in word.lowercase()) {
+        if (m.contains(c)) {
+            m.set(c, m.get(c)!! + 1)
+        } else {
+            m.set(c, 1)
+        }
+    }
+    return m
+}
+
+fun shallowclonemap(m: Map<Char, Int>): MutableMap<Char, Int> {
+    var mm = mutableMapOf<Char, Int>()
+    for (k in m.keys) {
+        mm.set(k, m.get(k)!!)
+    }
+    return mm
+}
+
+fun wordstickers(stickers: List<String>, word: String): Int {
+    var w = word2map(word)
+    var t = shallowclonemap(w)
+    var stick = ArrayList<Map<Char, Int>>()
+    for (s in stickers) {
+        val f = word2map(s)
+        for (c in f.keys) {
+            t.remove(c)
+        }
+        stick.add(f)
+    }
+    if (t.size > 0) {
+        return 0
+    }
+    var stack = arrayListOf(Pair(w, 0))
+    while (stack.size > 0) {
+        val st = stack.removeFirst()
+        if (st.first.size == 0) {
+            return st.second
+        } else {
+            val n = st.second + 1;
+            for (sti in stick) {
+                var sp = shallowclonemap(st.first)
+                var v = false
+                for (l in sti.keys) {
+                    if (sp.contains(l)) {
+                        v = true
+                        val p = sp.get(l)!! - sti.get(l)!!
+                        if (p > 0) {
+                            sp.put(l, p)
+                        } else {
+                            sp.remove(l)
+                        }
+                    }
+                }
+                if (v) {
+                    stack.add(Pair(sp, n))
+                }
+            }
+        }
+    }
+    return 0
+}
+
+fun main() {
+
+    if (wordstickers(listOf("perl", "raku", "python"), "peon") == 2) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (wordstickers(listOf("love", "hate", "angry"), "goat") == 3) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (wordstickers(listOf("come", "nation", "delta"), "accomodation") == 4) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (wordstickers(listOf("come", "country", "delta"), "accomodation") == 0) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-216/roger-bell-west/lua/ch-1.lua b/challenge-216/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..0de0a79536
--- /dev/null
+++ b/challenge-216/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,97 @@
+#! /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 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 propersize(t)
+   local l=0
+   for k,v in pairs(t) do
+      l = l + 1
+   end
+   return l
+end
+
+function word2set(word)
+   local s = {}
+   for c in string.gmatch(string.lower(word), "%a") do
+      s[c] = true
+   end
+   return s
+end
+
+function registrationnumber(words, reg)
+   local s = word2set(reg)
+   local out = {}
+   for _, w in ipairs(words) do
+      local ss = deepcopy(s)
+      for c, _ in pairs(word2set(w)) do
+         if s[c] ~= nil then
+            s[c] = nil
+            if propersize(s) == 0 then
+               table.insert(out, w)
+               break
+            end
+         end
+      end
+   end
+   return out
+end
+
+if recursive_compare(registrationnumber({"abc", "abcd", "bcd"}, "AB1 2CD"), {"abcd"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(registrationnumber({"job", "james", "bjorg"}, "007 JB"), {"job", "bjorg"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(registrationnumber({"crack", "road", "rac"}, "C7 RA2"), {"crack", "rac"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-216/roger-bell-west/lua/ch-2.lua b/challenge-216/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..da804cb8f1
--- /dev/null
+++ b/challenge-216/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,112 @@
+#! /usr/bin/lua
+
+function keys(t)
+   local a = {}
+   for k, v in pairs(t) do
+      table.insert(a, k)
+   end
+   return a
+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 propersize(t)
+   local l=0
+   for k,v in pairs(t) do
+      l = l + 1
+   end
+   return l
+end
+
+function word2map(word)
+   local m = {}
+   for c in string.gmatch(string.lower(word), "%a") do
+      if m[c] == nil then
+         m[c] = 1
+      else
+         m[c] = m[c] + 1
+      end
+   end
+   return m
+end
+
+function wordstickers(stickers, word)
+   local w = word2map(word)
+   local t = deepcopy(w)
+   local stick = {}
+   for _, s in ipairs(stickers) do
+      local f = word2map(s)
+      for _, c in ipairs(keys(f)) do
+         t[c] = nil
+      end
+      table.insert(stick, f)
+   end
+   if propersize(t) > 0 then
+      return 0
+   end
+   local stack = { {w, 0} }
+   while #stack > 0 do
+      local st = table.remove(stack, 1)
+      if propersize(st[1]) == 0 then
+         return st[2]
+      else
+         local n = st[2] + 1
+         for _a, sti in ipairs(stick) do
+            local sp = deepcopy(st[1])
+            local v = false
+            for _b, l in ipairs(keys(sti)) do
+               if sp[l] ~= nil then
+                  v = true
+                  p = sp[l] - sti[l]
+                  if p > 0 then
+                     sp[l] = p
+                  else
+                     sp[l] = nil
+                  end
+               end
+            end
+            if v then
+               table.insert(stack, {sp, n})
+            end
+         end
+      end
+   end
+end
+
+if wordstickers({"perl", "raku", "python"}, "peon") == 2 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if wordstickers({"love", "hate", "angry"}, "goat") == 3 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if wordstickers({"come", "nation", "delta"}, "accomodation") == 4 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if wordstickers({"come", "country", "delta"}, "accomodation") == 0 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-216/roger-bell-west/perl/ch-1.pl b/challenge-216/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..4fb06c032c
--- /dev/null
+++ b/challenge-216/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,35 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 3;
+
+is_deeply(registrationnumber(['abc', 'abcd', 'bcd'], 'AB1 2CD'), ['abcd'], 'example 1');
+is_deeply(registrationnumber(['job', 'james', 'bjorg'], '007 JB'), ['job', 'bjorg'], 'example 2');
+is_deeply(registrationnumber(['crack', 'road', 'rac'], 'C7 RA2'), ['crack', 'rac'], 'example 3');
+
+use Storable qw(dclone);
+
+sub word2set($word) {
+  return {map {$_ => 1} grep /[a-z]/, split '', lc($word)};
+}
+
+sub registrationnumber($words, $reg) {
+  my $s = word2set($reg);
+  my @out;
+  foreach my $w (@{$words}) {
+    my $ss = dclone($s);
+    foreach my $char (keys %{word2set($w)}) {
+      if (exists $ss->{$char}) {
+        delete $ss->{$char};
+        if (scalar %{$ss} == 0) {
+          push @out, $w;
+          last;
+        }
+      }
+    }
+  }
+  return \@out;
+}
diff --git a/challenge-216/roger-bell-west/perl/ch-2.pl b/challenge-216/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..2ad6af790c
--- /dev/null
+++ b/challenge-216/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,57 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 4;
+
+is(wordstickers(['perl', 'raku', 'python'], 'peon'), 2, 'example 1');
+is(wordstickers(['love', 'hate', 'angry'], 'goat'), 3, 'example 2');
+is(wordstickers(['come', 'nation', 'delta'], 'accomodation'), 4, 'example 3');
+is(wordstickers(['come', 'country', 'delta'], 'accomodation'), 0, 'example 4');
+
+use Storable qw(dclone);
+
+sub wordstickers($stickers, $word) {
+  my %w;
+  map {$w{$_}++} split '',lc($word);
+  my $t = dclone(\%w);
+  my @stick;
+  foreach my $s (@{$stickers}) {
+    my %f;
+    map {$f{$_}++} split '',lc($s);
+    map {delete $t->{$_}} keys %f;
+    push @stick, \%f;
+  }
+  if (scalar %{$t}) {
+    return 0;
+  }
+  my @stack = ([\%w, 0]);
+  while (scalar @stack > 0) {
+    my $st = shift @stack;
+    if (scalar %{$st->[0]} == 0) {
+      return $st->[1];
+    } else {
+      my $n = $st->[1] + 1;
+      foreach my $sti (@stick) {
+        my $sp = dclone($st->[0]);
+        my $v = 0;
+        foreach my $l (keys %{$sti}) {
+          if (exists $sp->{$l}) {
+            $v = 1;
+            my $p = $sp->{$l} - $sti->{$l};
+            if ($p > 0) {
+              $sp->{$l} = $p;
+            } else {
+              delete $sp->{$l};
+            }
+          }
+        }
+        if ($v) {
+          push @stack, [$sp, $n];
+        }
+      }
+    }
+  }
+}
diff --git a/challenge-216/roger-bell-west/postscript/ch-1.ps b/challenge-216/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..727c189748
--- /dev/null
+++ b/challenge-216/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,178 @@
+%!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
+
+/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
+
+/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
+
+
+% end included library code
+
+/word2set {
+    2 dict begin
+    /s 0 dict def
+    {
+        /c exch def
+        c 65 ge c 90 le and {
+            /c c 32 add def
+        } if
+        c 97 ge c 122 le and {
+            s c true put
+        } if
+    } forall
+    s
+    end
+} bind def
+
+/registrationnumber {
+    6 dict begin
+    /reg exch def
+    /words exch def
+    /s reg word2set def
+    [
+        words {
+            /w exch def
+            /ss s deepcopy def
+            w word2set keys {
+                /char exch def
+                ss char known {
+                    ss char undef
+                    ss length 0 eq {
+                        w
+                        exit
+                    } if
+                } if
+            } forall
+        } forall
+    ]
+    end
+} bind def
+
+(registrationnumber) test.start
+[(abc) (abcd) (bcd)] (AB1 2CD) registrationnumber [(abcd)] deepeq test
+[(job) (james) (bjorg)] (007 JB) registrationnumber [(job) (bjorg)] deepeq test
+[(crack) (road) (rac)] (C7 RA2) registrationnumber [(crack) (rac)] deepeq test
+test.end
diff --git a/challenge-216/roger-bell-west/postscript/ch-2.ps b/challenge-216/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..adede24f3c
--- /dev/null
+++ b/challenge-216/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,165 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/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.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
+
+/apop.left { % [a b c] -> [b c] a
+    dup 0 get exch
+    [ exch aload length -1 roll pop ] exch
+} 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
+
+/apush.right { % [a b] c -> [a b c]
+    exch
+    [ exch aload length 2 add -1 roll ]
+} bind def
+
+
+% end included library code
+
+/word2map {
+    2 dict begin
+    /m 0 dict def
+    {
+        /c exch def
+        c 65 ge c 90 le and {
+            /c c 32 add def
+        } if
+        c 97 ge c 122 le and {
+            m c known {
+                m c m c get 1 add put
+            } {
+                m c 1 put
+            } ifelse
+        } if
+    } forall
+    m
+    end
+} bind def
+
+/wordstickers {
+    12 dict begin
+    word2map /w exch def
+    /t w deepcopy def
+    /stick exch
+    [ exch
+      {
+          /f exch word2map def
+          f keys {
+              /c exch def
+              t c known {
+                  t c undef
+              } if
+          } forall
+          f
+      } forall
+    ] def
+    t length 0 gt {
+        0
+    } {
+        /stack [ [ w 0 ] ] def
+        {
+            stack apop.left /st exch def /stack exch def
+            st 0 get length 0 eq {
+                st 1 get
+                exit
+            } {
+                /n st 1 get 1 add def
+                stick {
+                    /sti exch def
+                    /sp st 0 get deepcopy def
+                    /v false def
+                    sti keys {
+                        /l exch def
+                        sp l known {
+                            /v true def
+                    /p sp l get sti l get sub def
+                            p 0 gt {
+                                sp l p put
+                            } {
+                                sp l undef
+                            } ifelse
+                        } if
+                    } forall
+                    v {
+                        /stack stack [ sp n ] apush.right def
+                    } if
+                } forall
+            } ifelse
+        } loop
+    } ifelse
+    end
+} bind def
+
+(wordstickers) test.start
+[(perl) (raku) (python)] (peon) wordstickers 2 eq test
+[(love) (hate) (angry)] (goat) wordstickers 3 eq test
+[(come) (nation) (delta)] (accomodation) wordstickers 4 eq test
+[(come) (country) (delta)] (accomodation) wordstickers 0 eq test
+test.end
diff --git a/challenge-216/roger-bell-west/python/ch-1.py b/challenge-216/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..adfba72f9a
--- /dev/null
+++ b/challenge-216/roger-bell-west/python/ch-1.py
@@ -0,0 +1,38 @@
+#! /usr/bin/python3
+
+from copy import deepcopy
+
+def word2set(word):
+  r = set()
+  for c in word.lower():
+    if c >= 'a' and c <= 'z':
+      r.add(c)
+  return r
+
+def registrationnumber(words, reg):
+  s = word2set(reg)
+  out = []
+  for w in words:
+    ss = deepcopy(s)
+    for char in word2set(w):
+      if char in ss:
+        ss -= set(char)
+        if len(ss) == 0:
+          out.append(w)
+          break
+  return out
+
+import unittest
+
+class TestRegistrationnumber(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(registrationnumber(["abc", "abcd", "bcd"], "AB1 2CD"), ["abcd"], 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(registrationnumber(["job", "james", "bjorg"], "007 JB"), ["job", "bjorg"], 'example 2'