Merge pull request #11477 from Firedrake/rogerbw-challenge-305

RogerBW solutions for challenge no. 305

23 files changed, 1636 insertions, 0 deletions

diff --git a/challenge-305/roger-bell-west/crystal/ch-1.cr b/challenge-305/roger-bell-west/crystal/ch-1.cr
new file mode 100755
index 0000000000..67645dd0e7
--- /dev/null
+++ b/challenge-305/roger-bell-west/crystal/ch-1.cr
@@ -0,0 +1,66 @@
+#! /usr/bin/crystal
+
+def isqrt(s)
+  if s <= 1
+    return s
+  end
+  x0 = s / 2;
+  x1 = (x0 + s / x0) / 2;
+  while x1 < x0
+    x0 = x1
+    x1 = (x0 + s / x0) / 2
+  end    
+  x0
+end
+
+def is_prime(n)
+  if n == 1
+    return false
+  end
+  if n>2 && n%2==0 
+    return false
+  end
+  if n>3 && n%3==0
+    return false
+  end
+  lim = isqrt(n)
+  k6 = 0;
+  while true
+    k6 += 6
+    (k6 - 1).step(to: k6 + 1, by: 2) do |t|
+      if t <= lim
+        if n % t == 0
+          return false
+        end
+      else
+        return true
+      end
+    end
+  end
+end
+
+def binaryprefix(a)
+  out = Array(Bool).new
+  n = 0
+  a.each do |x|
+    n *= 2
+    if x == 1
+      n += 1
+    end
+    out.push(is_prime(n))
+  end
+  out
+end
+
+require "spec"
+describe "binaryprefix" do
+  it "test_ex1" do
+    binaryprefix([1, 0, 1]).should eq [false, true, true]
+  end
+  it "test_ex2" do
+    binaryprefix([1, 1, 0]).should eq [false, true, false]
+  end
+  it "test_ex3" do
+    binaryprefix([1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1]).should eq [false, true, true, false, false, true, false, false, false, false, false, false, false, false, false, false, false, false, false, true]
+  end
+end
diff --git a/challenge-305/roger-bell-west/crystal/ch-2.cr b/challenge-305/roger-bell-west/crystal/ch-2.cr
new file mode 100755
index 0000000000..768adccfc3
--- /dev/null
+++ b/challenge-305/roger-bell-west/crystal/ch-2.cr
@@ -0,0 +1,36 @@
+#! /usr/bin/crystal
+
+def aliendictionary(a, dc)
+  mxl = a.map { |x| x.size }.max
+  dh = Hash(Char, Int64).new
+  dc.each_with_index do |c, i|
+    dh[c] = i.to_i64
+  end
+  b = a
+  numerics = Hash(String, Int64).new
+  b.each do |w|
+    n = 0.to_i64
+    cc = w.chars
+    0.upto(mxl - 1) do |i|
+      n *= 27.to_i64
+      if i < w.size
+        n += dh[cc[i]]
+      end
+    end
+    numerics[w] = n
+  end
+  b.sort! do |i, j|
+    numerics[i] <=> numerics[j]
+  end
+  b
+end
+
+require "spec"
+describe "aliendictionary" do
+  it "test_ex1" do
+    aliendictionary(["perl", "python", "raku"], ['h', 'l', 'a', 'b', 'y', 'd', 'e', 'f', 'g', 'i', 'r', 'k', 'm', 'n', 'o', 'p', 'q', 'j', 's', 't', 'u', 'v', 'w', 'x', 'c', 'z']).should eq ["raku", "python", "perl"]
+  end
+  it "test_ex2" do
+    aliendictionary(["the", "weekly", "challenge"], ['c', 'o', 'r', 'l', 'd', 'a', 'b', 't', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm', 'n', 'p', 'q', 's', 'w', 'u', 'v', 'x', 'y', 'z']).should eq ["challenge", "the", "weekly"]
+  end
+end
diff --git a/challenge-305/roger-bell-west/javascript/ch-1.js b/challenge-305/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..951d12bf8a
--- /dev/null
+++ b/challenge-305/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,89 @@
+#! /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 is_prime(candidate) {
+    if (candidate<2) {
+        return false
+    } else if (candidate==2) {
+        return true
+    } else if (candidate==3) {
+        return true
+    } else if (candidate % 2 == 0) {
+        return false
+    } else if (candidate % 3 == 0) {
+        return false
+    }
+    let anchor=0
+    let limit=Math.floor(Math.sqrt(candidate))
+    while (1) {
+        anchor+=6
+        for (let t = anchor-1; t <= anchor+1; t += 2) {
+            if (t > limit) {
+                return true
+            }
+            if (candidate % t == 0) {
+                return false
+            }
+        }
+    }
+}
+
+function binaryprefix(a) {
+    let out = [];
+    let n = 0;
+    for (let x of a) {
+        n *= 2
+        if (x == 1) {
+            n += 1;
+        }
+        out.push(is_prime(n));
+    }
+    return out;
+}
+
+if (deepEqual(binaryprefix([1, 0, 1]), [false, true, true])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(binaryprefix([1, 1, 0]), [false, true, false])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(binaryprefix([1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1]), [false, true, true, false, false, true, false, false, false, false, false, false, false, false, false, false, false, false, false, true])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-305/roger-bell-west/javascript/ch-2.js b/challenge-305/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..3b9bf69629
--- /dev/null
+++ b/challenge-305/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,74 @@
+#! /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 aliendictionary(a, dc) {
+    const mxl = Math.max(...a.map(x => x.length));
+    let dh = new Map;
+    dc.forEach((c, i) => {
+        dh.set(c, i + 1);
+    });
+    let b = [...a];
+    let numerics = new Map;
+    for (let w of a) {
+        let n = 0n;
+        let cc = w.split("");
+        for (let i = 0; i < mxl; i++) {
+            n *= 27n;
+            if (i < w.length) {
+                n += BigInt(dh.get(cc[i]));
+            }
+        }
+        numerics.set(w, n);
+    }
+    b.sort(function(i, j) {
+        const d = numerics.get(i) - numerics.get(j);
+        if (d < 0) {
+            return -1;
+        } else if (d > 0) {
+            return 1;
+        }
+        return 0;
+    });
+    return b;
+}
+
+if (deepEqual(aliendictionary(['perl', 'python', 'raku'], ['h', 'l', 'a', 'b', 'y', 'd', 'e', 'f', 'g', 'i', 'r', 'k', 'm', 'n', 'o', 'p', 'q', 'j', 's', 't', 'u', 'v', 'w', 'x', 'c', 'z']), ['raku', 'python', 'perl'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(aliendictionary(['the', 'weekly', 'challenge'], ['c', 'o', 'r', 'l', 'd', 'a', 'b', 't', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm', 'n', 'p', 'q', 's', 'w', 'u', 'v', 'x', 'y', 'z']), ['challenge', 'the', 'weekly'])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-305/roger-bell-west/kotlin/ch-1.kt b/challenge-305/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..27e9070714
--- /dev/null
+++ b/challenge-305/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,76 @@
+fun isqrt(s: Int): Int {
+    if (s <= 1) {
+        return s
+    } else {
+        var x0 = s / 2
+        var x1 = (x0 + s / x0) / 2
+        while (x1 < x0) {
+            x0 = x1
+            x1 = (x0 + s / x0) / 2
+        }
+        return x0
+    }
+}
+
+fun is_prime(candidate: Int): Boolean {
+    if (candidate < 2) {
+        return false
+    } else if (candidate==2) {
+        return true
+    } else if (candidate==3) {
+        return true
+    } else if (candidate % 2 == 0) {
+        return false
+    } else if (candidate % 3 == 0) {
+        return false
+    }
+    var anchor=0
+    val limit = isqrt(candidate)
+    while (true) {
+        anchor += 6
+        for (t in anchor-1..anchor+1 step 2) {
+            if (t > limit) {
+                return true
+            }
+            if (candidate % t == 0) {
+                return false
+            }
+        }
+    }
+}
+
+fun binaryprefix(a: List<Int>): List<Boolean> {
+    var out =  ArrayList<Boolean>()
+    var n = 0
+    for (x in a) {
+        n *= 2
+        if (x == 1) {
+            n += 1
+        }
+        out.add(is_prime(n))
+    }
+    return out.toList()
+}
+
+fun main() {
+
+    if (binaryprefix(listOf(1, 0, 1)) == listOf(false, true, true)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (binaryprefix(listOf(1, 1, 0)) == listOf(false, true, false)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (binaryprefix(listOf(1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1)) == listOf(false, true, true, false, false, true, false, false, false, false, false, false, false, false, false, false, false, false, false, true)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-305/roger-bell-west/kotlin/ch-2.kt b/challenge-305/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..d678e4d8e1
--- /dev/null
+++ b/challenge-305/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,48 @@
+fun aliendictionary(a: List<String>, dc: List<Char>): List<String> {
+    val mxl = a.map{it.length}.maxOrNull()!!
+    var dh = mutableMapOf<Char, Int>()
+    dc.forEachIndexed{i, c ->
+                          dh.set(c, i + 1)
+    }
+    var numerics = mutableMapOf<String, Long>()
+    for (w in a) {
+        var n = 0.toLong()
+        val cc = w.toList()
+        for (i in 0 .. mxl - 1) {
+            n *= 27.toLong()
+            if (i < w.length) {
+                n += dh.getValue(cc[i]).toLong()
+            }
+        }
+        numerics.set(w, n)
+    }
+    val customComparator = Comparator {
+        i: String, j: String ->
+            val d = numerics.getValue(i) - numerics.getValue(j)
+        if (d > 0L) {
+            1
+        } else if (d < 0L) {
+            -1
+        } else {
+            0
+        }
+    }
+    return a.sortedWith(customComparator)
+}
+
+fun main() {
+
+    if (aliendictionary(listOf("perl", "python", "raku"), listOf('h', 'l', 'a', 'b', 'y', 'd', 'e', 'f', 'g', 'i', 'r', 'k', 'm', 'n', 'o', 'p', 'q', 'j', 's', 't', 'u', 'v', 'w', 'x', 'c', 'z')) == listOf("raku", "python", "perl")) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(' ')
+    if (aliendictionary(listOf("the", "weekly", "challenge"), listOf('c', 'o', 'r', 'l', 'd', 'a', 'b', 't', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm', 'n', 'p', 'q', 's', 'w', 'u', 'v', 'x', 'y', 'z')) == listOf("challenge", "the", "weekly")) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-305/roger-bell-west/lua/ch-1.lua b/challenge-305/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..a5a16f3d93
--- /dev/null
+++ b/challenge-305/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,92 @@
+#! /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 is_prime(candidate)
+   if candidate<2 then
+      return false
+   elseif candidate==2 then
+      return true
+   elseif candidate==3 then
+      return true
+   elseif candidate % 2 == 0 then
+      return false
+   elseif candidate % 3 == 0 then
+      return false
+   end
+   local anchor=0
+   local limit=math.floor(math.sqrt(candidate))
+   while true do
+      anchor = anchor + 6
+      for t = anchor-1,anchor+1,2 do
+         if t > limit then
+            return true
+         end
+         if candidate % t == 0 then
+            return false
+         end
+      end
+   end
+end
+
+function binaryprefix(a)
+   local out = {}
+   local n = 0
+   for _, x in ipairs(a) do
+      n = n * 2
+      if x == 1 then
+         n = n + 1
+      end
+      table.insert(out, is_prime(n))
+   end
+   return out
+end
+
+if recursive_compare(binaryprefix({1, 0, 1}), {false, true, true}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(binaryprefix({1, 1, 0}), {false, true, false}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(binaryprefix({1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1}), {false, true, true, false, false, true, false, false, false, false, false, false, false, false, false, false, false, false, false, true}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-305/roger-bell-west/lua/ch-2.lua b/challenge-305/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..e9974e511a
--- /dev/null
+++ b/challenge-305/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,86 @@
+#! /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 aliendictionary(a, dc)
+   local mxl = 0
+   for _, w in ipairs(a) do
+      mxl = math.max(mxl, #w)
+   end
+   local dh = {}
+   for i, c in ipairs(dc) do
+      dh[c] = i
+   end
+   local b = a
+   local numerics = {}
+   for _, w in ipairs(a) do
+      local n = 0
+      local cc = split(w)
+      for i = 1, mxl do
+         n = n * 27
+         if i <= #w then
+            n = n + dh[cc[i]]
+         end
+      end
+      numerics[w] = n
+   end
+   table.sort(b,
+              function(i, j)
+                 return numerics[i] < numerics[j]
+              end
+   )
+   return b
+end
+
+if recursive_compare(aliendictionary({"perl", "python", "raku"}, {"h", "l", "a", "b", "y", "d", "e", "f", "g", "i", "r", "k", "m", "n", "o", "p", "q", "j", "s", "t", "u", "v", "w", "x", "c", "z"}), {"raku", "python", "perl"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(aliendictionary({"the", "weekly", "challenge"}, {"c", "o", "r", "l", "d", "a", "b", "t", "e", "f", "g", "h", "i", "j", "k", "m", "n", "p", "q", "s", "w", "u", "v", "x", "y", "z"}), {"challenge", "the", "weekly"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-305/roger-bell-west/perl/ch-1.pl b/challenge-305/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..e05413d206
--- /dev/null
+++ b/challenge-305/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,26 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 3;
+
+is_deeply(binaryprefix([1, 0, 1]), [0, 1, 1], 'example 1');
+is_deeply(binaryprefix([1, 1, 0]), [0, 1, 0], 'example 2');
+is_deeply(binaryprefix([1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1]), [0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1], 'example 3');
+
+use Math::Prime::Util qw(is_prime);
+
+sub binaryprefix($a) {
+  my @out;
+  my $n = 0;
+  foreach my $x (@{$a}) {
+    $n *= 2;
+    if ($x == 1) {
+      $n++;
+    }
+    push @out, is_prime($n)?1:0;
+  }
+  \@out;
+}
diff --git a/challenge-305/roger-bell-west/perl/ch-2.pl b/challenge-305/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..ba5b1724b4
--- /dev/null
+++ b/challenge-305/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,35 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 2;
+
+is_deeply(aliendictionary(['perl', 'python', 'raku'], ['h', 'l', 'a', 'b', 'y', 'd', 'e', 'f', 'g', 'i', 'r', 'k', 'm', 'n', 'o', 'p', 'q', 'j', 's', 't', 'u', 'v', 'w', 'x', 'c', 'z']), ['raku', 'python', 'perl'], 'example 1');
+is_deeply(aliendictionary(['the', 'weekly', 'challenge'], ['c', 'o', 'r', 'l', 'd', 'a', 'b', 't', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm', 'n', 'p', 'q', 's', 'w', 'u', 'v', 'x', 'y', 'z']), ['challenge', 'the', 'weekly'], 'example 2');
+
+use List::Util qw(max);
+
+sub aliendictionary($a, $dc) {
+  my $mxl = max(map {length($_)} @{$a});
+  my %dh;
+  while (my ($i, $c) = each @{$dc}) {
+    $dh{$c} = $i + 1;
+  }
+  my @b = @{$a};
+  my %numerics;
+  foreach my $w (@b) {
+    my $n = 0;
+    my @cc = split '', $w;
+    foreach my $i (0 .. $mxl - 1) {
+      $n *= 27;
+      if ($i < length($w)) {
+        $n += $dh{$cc[$i]};
+      }
+    }
+    $numerics{$w} = $n;
+  }
+  @b = sort { $numerics{$::a} <=> $numerics{$::b} } @b;
+  return \@b;
+}
diff --git a/challenge-305/roger-bell-west/postscript/ch-1.ps b/challenge-305/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..4515cf8337
--- /dev/null
+++ b/challenge-305/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,183 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/isqrt {
+    0 dict begin
+    /s exch def
+    s 1 le {
+        s
+    } {
+        /x0 s 2 idiv def
+        /x1 x0 s x0 idiv add 2 idiv def
+        {
+            x1 x0 ge {
+                exit
+            } if
+            /x0 x1 def
+            /x1 x0 s x0 idiv add 2 idiv def
+        } loop
+        x0
+    } ifelse
+    end
+} 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
+
+/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
+
+/isprime {
+    4 dict begin
+    /candidate exch def
+    1 {
+        candidate 2 lt {
+            false
+            exit
+        } if
+        candidate 2 eq {
+            true
+            exit
+        } if
+        candidate 2 mod 0 eq {
+            false
+            exit
+        } if
+        candidate 3 eq {
+            true
+            exit
+        } if
+        candidate 3 mod 0 eq {
+            false
+            exit
+        } if
+        /prime true def
+        /limit candidate isqrt 1 add def
+        /anchor 0 def
+        {
+            /anchor anchor 6 add def
+            anchor limit gt {
+                exit
+            } if
+            [ -1 1 ] {
+                anchor add candidate exch mod 0 eq {
+                    /prime false def
+                    exit
+                } if
+            } forall
+            prime false eq {
+                exit
+            } if
+        } loop
+        prime
+    } repeat
+    end
+} bind def
+
+
+% end included library code
+
+/binaryprefix {
+    0 dict begin
+    [ exch
+      /n 0 def
+      {
+          /n n 2 mul def
+          1 eq {
+              /n n 1 add def
+          } if
+          n isprime
+      } forall
+    ]
+    end
+} bind def
+
+(binaryprefix) test.start
+[1 0 1] binaryprefix [false true true] deepeq test
+[1 1 0] binaryprefix [false true false] deepeq test
+[1 1 1 1 0 1 0 0 0 0 1 0 1 0 0 1 0 0 0 1] binaryprefix [false true true false false true false false false false false false false false false false false false false true] deepeq test
+test.end
diff --git a/challenge-305/roger-bell-west/postscript/ch-2.ps b/challenge-305/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..68f1a70cc2
--- /dev/null
+++ b/challenge-305/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,318 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/map { % array proc -> array
+    2 dict begin
+    /p exch def
+    [ exch
+      {
+          p
+      } forall
+    ]
+    end
+} bind def
+
+/quicksort.main { % lo hi -> (null)
+    3 dict begin
+    /hi exch def
+    /lo exch def
+    /xit false def
+    lo 0 lt {
+        /xit true def
+    } if
+    hi 0 lt {
+        /xit true def
+    } if
+    lo hi ge {
+        /xit true def
+    } if
+    xit not {
+        /p quicksort.partition def
+        lo p quicksort.main
+        p 1 add hi quicksort.main
+    } if
+    end
+} bind def
+
+/a2s {
+    2 dict begin
+    /i exch def
+    i length dup string /o exch def
+    1 sub 0 exch 1 exch {
+        dup i 3 -1 roll get o 3 1 roll put
+    } for
+    o
+    end
+} bind def
+
+/listmax {
+    { max } reduce
+} 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
+