From 1dab6f83512b9ae7a3d5347234470f8d6f4e4598 Mon Sep 17 00:00:00 2001
From: Roger Bell_West <roger@firedrake.org>
Date: Tue, 28 May 2024 09:56:15 +0100
Subject: RogerBW solutions for challenge no. 271

---
 challenge-271/roger-bell-west/crystal/ch-1.cr    |  25 +++
 challenge-271/roger-bell-west/crystal/ch-2.cr    |  25 +++
 challenge-271/roger-bell-west/javascript/ch-1.js |  28 +++
 challenge-271/roger-bell-west/javascript/ch-2.js |  71 +++++++
 challenge-271/roger-bell-west/kotlin/ch-1.kt     |  30 +++
 challenge-271/roger-bell-west/kotlin/ch-2.kt     |  39 ++++
 challenge-271/roger-bell-west/lua/ch-1.lua       |  41 ++++
 challenge-271/roger-bell-west/lua/ch-2.lua       |  72 +++++++
 challenge-271/roger-bell-west/perl/ch-1.pl       |  24 +++
 challenge-271/roger-bell-west/perl/ch-2.pl       |  28 +++
 challenge-271/roger-bell-west/postscript/ch-1.ps | 100 ++++++++++
 challenge-271/roger-bell-west/postscript/ch-2.ps | 239 +++++++++++++++++++++++
 challenge-271/roger-bell-west/python/ch-1.py     |  21 ++
 challenge-271/roger-bell-west/python/ch-2.py     |  22 +++
 challenge-271/roger-bell-west/raku/ch-1.p6       |  22 +++
 challenge-271/roger-bell-west/raku/ch-2.p6       |  25 +++
 challenge-271/roger-bell-west/ruby/ch-1.rb       |  30 +++
 challenge-271/roger-bell-west/ruby/ch-2.rb       |  41 ++++
 challenge-271/roger-bell-west/rust/ch-1.rs       |  29 +++
 challenge-271/roger-bell-west/rust/ch-2.rs       |  25 +++
 challenge-271/roger-bell-west/scala/ch-1.scala   |  29 +++
 challenge-271/roger-bell-west/scala/ch-2.scala   |  41 ++++
 challenge-271/roger-bell-west/tests.json         |  38 ++++
 23 files changed, 1045 insertions(+)
 create mode 100755 challenge-271/roger-bell-west/crystal/ch-1.cr
 create mode 100755 challenge-271/roger-bell-west/crystal/ch-2.cr
 create mode 100755 challenge-271/roger-bell-west/javascript/ch-1.js
 create mode 100755 challenge-271/roger-bell-west/javascript/ch-2.js
 create mode 100644 challenge-271/roger-bell-west/kotlin/ch-1.kt
 create mode 100644 challenge-271/roger-bell-west/kotlin/ch-2.kt
 create mode 100755 challenge-271/roger-bell-west/lua/ch-1.lua
 create mode 100755 challenge-271/roger-bell-west/lua/ch-2.lua
 create mode 100755 challenge-271/roger-bell-west/perl/ch-1.pl
 create mode 100755 challenge-271/roger-bell-west/perl/ch-2.pl
 create mode 100644 challenge-271/roger-bell-west/postscript/ch-1.ps
 create mode 100644 challenge-271/roger-bell-west/postscript/ch-2.ps
 create mode 100755 challenge-271/roger-bell-west/python/ch-1.py
 create mode 100755 challenge-271/roger-bell-west/python/ch-2.py
 create mode 100755 challenge-271/roger-bell-west/raku/ch-1.p6
 create mode 100755 challenge-271/roger-bell-west/raku/ch-2.p6
 create mode 100755 challenge-271/roger-bell-west/ruby/ch-1.rb
 create mode 100755 challenge-271/roger-bell-west/ruby/ch-2.rb
 create mode 100755 challenge-271/roger-bell-west/rust/ch-1.rs
 create mode 100755 challenge-271/roger-bell-west/rust/ch-2.rs
 create mode 100644 challenge-271/roger-bell-west/scala/ch-1.scala
 create mode 100644 challenge-271/roger-bell-west/scala/ch-2.scala
 create mode 100644 challenge-271/roger-bell-west/tests.json

diff --git a/challenge-271/roger-bell-west/crystal/ch-1.cr b/challenge-271/roger-bell-west/crystal/ch-1.cr
new file mode 100755
index 0000000000..b892354b6f
--- /dev/null
+++ b/challenge-271/roger-bell-west/crystal/ch-1.cr
@@ -0,0 +1,25 @@
+#! /usr/bin/crystal
+
+def maximumones(a)
+  ax = a.map { |r| r.sum }
+  am = ax.max
+  ax.each_with_index do |n, i|
+    if n == am
+      return i + 1
+    end
+  end
+  0
+end
+
+require "spec"
+describe "#tmpl_var name=function>" do
+  it "test_ex1" do
+    maximumones([[0, 1], [1, 0]]).should eq 1
+  end
+  it "test_ex2" do
+    maximumones([[0, 0, 0], [1, 0, 1]]).should eq 2
+  end
+  it "test_ex3" do
+    maximumones([[0, 0], [1, 1], [0, 0]]).should eq 2
+  end
+end
diff --git a/challenge-271/roger-bell-west/crystal/ch-2.cr b/challenge-271/roger-bell-west/crystal/ch-2.cr
new file mode 100755
index 0000000000..bd112f9963
--- /dev/null
+++ b/challenge-271/roger-bell-west/crystal/ch-2.cr
@@ -0,0 +1,25 @@
+#! /usr/bin/crystal
+
+def sortbyonebits(a)
+  c = Hash(Int32, Int32).new
+  Set.new(a).each do |n|
+    c[n] = n.popcount
+  end
+  a.sort do |aa, bb|
+    if c[aa] == c[bb]
+      aa <=> bb
+    else
+      c[aa] <=> c[bb]
+    end
+  end
+end
+
+require "spec"
+describe "#tmpl_var name=function>" do
+  it "test_ex1" do
+    sortbyonebits([0, 1, 2, 3, 4, 5, 6, 7, 8]).should eq [0, 1, 2, 4, 8, 3, 5, 6, 7]
+  end
+  it "test_ex2" do
+    sortbyonebits([1024, 512, 256, 128, 64]).should eq [64, 128, 256, 512, 1024]
+  end
+end
diff --git a/challenge-271/roger-bell-west/javascript/ch-1.js b/challenge-271/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..c1feb13490
--- /dev/null
+++ b/challenge-271/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,28 @@
+#! /usr/bin/node
+
+"use strict"
+
+function maximumones(a) {
+    const ax = a.map(r => r.reduce((x, y) => x + y));
+    const am = Math.max(...ax);
+    return ax.indexOf(am) + 1;
+}
+
+if (maximumones([[0, 1], [1, 0]]) == 1) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (maximumones([[0, 0, 0], [1, 0, 1]]) == 2) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (maximumones([[0, 0], [1, 1], [0, 0]]) == 2) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-271/roger-bell-west/javascript/ch-2.js b/challenge-271/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..2ab90b66f5
--- /dev/null
+++ b/challenge-271/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,71 @@
+#! /usr/bin/node
+
+"use strict"
+
+function popcount64(x0) {
+    const M1  = 0x5555555555555555n;
+    const M2  = 0x3333333333333333n;
+    const M4  = 0x0f0f0f0f0f0f0f0fn;
+    const H01 = 0x0101010101010101n;
+    let x = BigInt(x0);
+    x -= (x >> 1n) & M1;
+    x = (x & M2) + ((x >> 2n) & M2);
+    x = (x + (x >> 4n)) & M4;
+    return Number((x * H01) >> 56n);
+}
+
+function sortbyonebits(a) {
+    let b = a;
+    let c = new Map;
+    for (let n of a) {
+        c.set(n, popcount64(n));
+    }
+    b.sort(function(aa, bb) {
+        if (c.get(aa) == c.get(bb)) {
+            return aa - bb;
+        } else {
+            return c.get(aa) - c.get(bb);
+        }
+    });
+    return b;
+}
+
+// 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;
+    }
+}
+
+if (deepEqual(sortbyonebits([0, 1, 2, 3, 4, 5, 6, 7, 8]), [0, 1, 2, 4, 8, 3, 5, 6, 7])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(sortbyonebits([1024, 512, 256, 128, 64]), [64, 128, 256, 512, 1024])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-271/roger-bell-west/kotlin/ch-1.kt b/challenge-271/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..12d2840d6f
--- /dev/null
+++ b/challenge-271/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,30 @@
+import kotlin.math.*
+
+fun maximumones(a: List<List<Int>>): Int {
+    val ax = a.map{it.sum()}.toList()
+    val am = ax.maxOrNull()!!
+    return ax.indexOf(am) + 1
+}
+
+fun main() {
+
+    if (maximumones(listOf(listOf(0, 1), listOf(1, 0))) == 1) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (maximumones(listOf(listOf(0, 0, 0), listOf(1, 0, 1))) == 2) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (maximumones(listOf(listOf(0, 0), listOf(1, 1), listOf(0, 0))) == 2) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-271/roger-bell-west/kotlin/ch-2.kt b/challenge-271/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..b4cd5688dd
--- /dev/null
+++ b/challenge-271/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,39 @@
+fun popcount64(x0: Int): Int {
+    val M1  = 0x5555555555555555
+    val M2  = 0x3333333333333333
+    val M4  = 0x0f0f0f0f0f0f0f0f
+    val H01 = 0x0101010101010101
+    var x = x0.toLong()
+    x -= (x shr 1) and M1
+    x = (x and M2) + ((x shr 2) and M2)
+    x = (x + (x shr 4)) and M4
+    return ((x * H01) shr 56).toInt()
+}
+
+fun sortbyonebits(a: List<Int>): List<Int> {
+    var b = ArrayList(a)
+    var c = mutableMapOf<Int, Int>()
+    for (v in a.toSet()) {
+        c[v] = popcount64(v);
+    }
+    b.sort()
+    b.sortBy { c[it] }
+    return b.toList()
+}
+
+fun main() {
+
+    if (sortbyonebits(listOf(0, 1, 2, 3, 4, 5, 6, 7, 8)) == listOf(0, 1, 2, 4, 8, 3, 5, 6, 7)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (sortbyonebits(listOf(1024, 512, 256, 128, 64)) == listOf(64, 128, 256, 512, 1024)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-271/roger-bell-west/lua/ch-1.lua b/challenge-271/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..f905d09c15
--- /dev/null
+++ b/challenge-271/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,41 @@
+#! /usr/bin/lua
+
+function maximumones(a)
+   local ax = {}
+   for i, r in ipairs(a) do
+      local s = 0
+      for j, t in ipairs(r) do
+         s = s + t
+      end
+      table.insert(ax, s)
+   end
+   local am = math.max(table.unpack(ax))
+   for i, n in ipairs(ax) do
+      if n == am then
+         return i
+      end
+   end
+   return 0
+end
+
+if maximumones({{0, 1}, {1, 0}}) == 1 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if maximumones({{0, 0, 0}, {1, 0, 1}}) == 2 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if maximumones({{0, 0}, {1, 1}, {0, 0}}) == 2 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-271/roger-bell-west/lua/ch-2.lua b/challenge-271/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..2dcf713dec
--- /dev/null
+++ b/challenge-271/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,72 @@
+#! /usr/bin/lua
+
+function popcount(x0) -- adapted from https://gist.github.com/davidm/2065267
+   local x = x0
+   local c = 0
+   while x ~= 0 do
+      x = x & (x - 1)
+      c = c + 1
+   end
+   return c
+end
+
+function sortbyonebits(a)
+   local b = a
+   local c = {}
+   for _, v in ipairs(b) do
+      if c[v] == nil then
+         c[v] = popcount(v)
+      end
+   end
+   table.sort(b, function(a, b)
+                 if c[a] == c[b] then
+                    return a < b
+                 else
+                    return c[a] < c[b]
+                 end
+   end)
+   return b
+end
+
+-- 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
+
+if recursive_compare(sortbyonebits({0, 1, 2, 3, 4, 5, 6, 7, 8}), {0, 1, 2, 4, 8, 3, 5, 6, 7}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(sortbyonebits({1024, 512, 256, 128, 64}), {64, 128, 256, 512, 1024}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
diff --git a/challenge-271/roger-bell-west/perl/ch-1.pl b/challenge-271/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..dd9e831a7f
--- /dev/null
+++ b/challenge-271/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,24 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 3;
+
+is(maximumones([[0, 1], [1, 0]]), 1, 'example 1');
+is(maximumones([[0, 0, 0], [1, 0, 1]]), 2, 'example 2');
+is(maximumones([[0, 0], [1, 1], [0, 0]]), 2, 'example 3');
+
+use List::Util qw(sum max);
+
+sub maximumones($a) {
+  my @ax = map {sum(@{$_})} @{$a};
+  my $am = max(@ax);
+  while (my ($i, $n) = each @ax) {
+    if ($n == $am) {
+      return $i + 1;
+    }
+  }
+  return 0;
+}
diff --git a/challenge-271/roger-bell-west/perl/ch-2.pl b/challenge-271/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..025ed6a2f6
--- /dev/null
+++ b/challenge-271/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,28 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 2;
+
+is_deeply(sortbyonebits([0, 1, 2, 3, 4, 5, 6, 7, 8]), [0, 1, 2, 4, 8, 3, 5, 6, 7], 'example 1');
+is_deeply(sortbyonebits([1024, 512, 256, 128, 64]), [64, 128, 256, 512, 1024], 'example 2');
+
+sub popcount64($x0) {
+  no warnings 'portable';
+  use constant M1  => 0x5555555555555555;
+  use constant M2  => 0x3333333333333333;
+  use constant M4  => 0x0f0f0f0f0f0f0f0f;
+  use constant H01 => 0x0101010101010101;
+  my $x = $x0;
+  $x -= ($x >> 1) & M1;
+  $x = ($x & M2) + (($x >> 2) & M2);
+  $x = ($x + ($x >> 4)) & M4;
+  return ($x * H01) >> 56;
+}
+
+sub sortbyonebits($a) {
+  my %c = map {$_ => popcount64($_)} @{$a};
+  return [sort {$c{$::a} <=> $c{$::b} || $::a <=> $::b} @{$a}];
+}
diff --git a/challenge-271/roger-bell-west/postscript/ch-1.ps b/challenge-271/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..0ae7a744b4
--- /dev/null
+++ b/challenge-271/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,100 @@
+%!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
+
+/listmax {
+    { max } reduce
+} bind def
+
+/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
+
+
+/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
+
+/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
+
+/enumerate.array {
+    1 dict begin
+    /a exch def
+    [
+      0 1 a length 1 sub {
+          [ exch dup a exch get ]
+      } for
+    ]
+    end
+} bind def
+
+
+% end included library code
+
+/maximumones {
+    0 dict begin
+    /ax exch { { add } reduce } map def
+    /am ax listmax def
+    -1
+    ax enumerate.array {
+        aload pop
+        /n exch def
+        /i exch def
+        n am eq {
+            pop i
+            exit
+        } if
+    } forall
+    1 add
+    end
+} bind def
+
+(maximumones) test.start
+[[0 1] [1 0]] maximumones 1 eq test
+[[0 0 0] [1 0 1]] maximumones 2 eq test
+[[0 0] [1 1] [0 0]] maximumones 2 eq test
+test.end
diff --git a/challenge-271/roger-bell-west/postscript/ch-2.ps b/challenge-271/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..b11dd84478
--- /dev/null
+++ b/challenge-271/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,239 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/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
+
+/quicksort.with_comparator { % [ a c b ] { comparator } -> [ a b c ]
+    2 dict begin
+    /cmp exch def
+    /arr exch def
+    arr length 0 gt {
+        0 arr length 1 sub quicksort.main
+    } if
+    arr
+    end
+} bind def
+
+/quicksort.partition {
+    3 dict begin
+    /pivot arr hi lo add 2 idiv get def
+    /i lo 1 sub def
+    /j hi 1 add def
+    {
+        {
+            /i i 1 add def
+            arr i get pivot cmp 0 ge {
+                exit
+            } if
+        } loop
+        {
+            /j j 1 sub def
+            arr j get pivot cmp 0 le {
+                exit
+            } if
+        } loop
+        i j ge {
+            j
+            exit
+        } if
+        i j quicksort.swap
+    } loop
+    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
+
+/quicksort.swap {
+    2 dict begin
+    /bi exch def
+    /ai exch def
+    arr ai get
+    arr bi get
+    arr exch ai exch put
+    arr exch bi exch put
+    end
+} bind def
+
+/quicksort.cmp {
+    2 copy
+    lt {
+        pop pop -1
+    } {
+        gt {
+            1
+        } {
+            0
+        } ifelse
+    } ifelse
+} bind def
+
+/unique {
+    toset keys
+} bind def
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+/keys { % dict -> array of dict keys
+    [ exch
+      {
+          pop
+      } forall
+    ]
+} 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
+
+/toset { % array -> dict of (value, true)
+    << exch
+       {
+           true
+       } forall
+    >>
+} 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
+
+/popcount32 {
+    0 dict begin
+    /M1  16#55555555 def
+    /M2  16#33333333 def
+    /M4  16#0f0f0f0f def
+    /H01 16#01010101 def
+    /x exch def
+    /x x x -1 bitshift M1 and sub def
+    /x x M2 and x -2 bitshift M2 and add def
+    /x x x -4 bitshift add M4 and def
+    x H01 mul -24 bitshift
+    end
+} bind def
+
+/sortbyonebits {
+    2 dict begin
+    /a exch def
+    /c <<
+           a unique {
+               dup popcount32
+           } forall
+       >> def
+    a {
+        2 copy c exch get exch c exch get exch quicksort.cmp
+        dup
+        0 eq {
+            pop
+            quicksort.cmp
+        } {
+            3 1 roll pop pop
+        } ifelse
+    } quicksort.with_comparator
+    end
+} bind def
+
+(sortbyonebits) test.start
+[0 1 2 3 4 5 6 7 8] sortbyonebits [0 1 2 4 8 3 5 6 7] deepeq test
+[1024 512 256 128 64] sortbyonebits [64 128 256 512 1024] deepeq test
+test.end
diff --git a/challenge-271/roger-bell-west/python/ch-1.py b/challenge-271/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..b9dfca3fb9
--- /dev/null
+++ b/challenge-271/roger-bell-west/python/ch-1.py
@@ -0,0 +1,21 @@
+#! /usr/bin/python3
+
+def maximumones(a):
+  ax = [sum(r) for r in a]
+  am = max(ax)
+  return [i for i, n in enumerate(ax) if n == am][0] + 1
+
+import unittest
+
+class TestMaximumones(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(maximumones([[0, 1], [1, 0]]), 1, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(maximumones([[0, 0, 0], [1, 0, 1]]), 2, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(maximumones([[0, 0], [1, 1], [0, 0]]), 2, 'example 3')
+
+unittest.main()
diff --git a/challenge-271/roger-bell-west/python/ch-2.py b/challenge-271/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..07cd54d1f1
--- /dev/null
+++ b/challenge-271/roger-bell-west/python/ch-2.py
@@ -0,0 +1,22 @@
+#! /usr/bin/python3
+
+def sortbyonebits(a):
+  c = dict()
+  for i in a:
+    c[i] = i.bit_count()
+  b = a
+  b.sort()
+  b.sort(key = lambda i: c[i])
+  return b
+
+import unittest
+
+class TestSortbyonebits(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(sortbyonebits([0, 1, 2, 3, 4, 5, 6, 7, 8]), [0, 1, 2, 4, 8, 3, 5, 6, 7], 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(sortbyonebits([1024, 512, 256, 128, 64]), [64, 128, 256, 512, 1024], 'example 2')
+
+unittest.main()
diff --git a/challenge-271/roger-bell-west/raku/ch-1.p6 b/challenge-271/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..1763a33cb3
--- /dev/null
+++ b/challenge-271/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,22 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 3;
+
+is(maximumones([[0, 1], [1, 0]]), 1, 'example 1');
+is(maximumones([[0, 0, 0], [1, 0, 1]]), 2, 'example 2');
+is(maximumones([[0, 0], [1, 1], [0, 0]]), 2, 'example 3');
+
+sub maximumones(@a) {
+    my @ax = @a.map({$_.sum()});
+    my $am = @ax.max();
+    for @ax.kv -> $i, $n {
+        if ($n == $am) {
+            return $i + 1;
+            }
+    }
+    return 0;
+}
+
+        
diff --git a/challenge-271/roger-bell-west/raku/ch-2.p6 b/challenge-271/roger-bell-west/raku/ch-2.p6
new file mode 100755
index 0000000000..0852ebd042
--- /dev/null
+++ b/challenge-271/roger-bell-west/raku/ch-2.p6
@@ -0,0 +1,25 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 2;
+
+is-deeply(sortbyonebits([0, 1, 2, 3, 4, 5, 6, 7, 8]), [0, 1, 2, 4, 8, 3, 5, 6, 7], 'example 1');
+is-deeply(sortbyonebits([1024, 512, 256, 128, 64]), [64, 128, 256, 512, 1024], 'example 2');
+
+sub popcount64($x0) {
+  constant $M1  = 0x5555555555555555;
+  constant $M2  = 0x3333333333333333;
+  constant $M4  = 0x0f0f0f0f0f0f0f0f;
+  constant $H01 = 0x0101010101010101;
+  my $x = $x0;
+  $x -= ($x +> 1) +& $M1;
+  $x = ($x +& $M2) + (($x +> 2) +& $M2);
+  $x = ($x + ($x +> 4)) +& $M4;
+  return ($x * $H01) +> 56;
+}
+
+sub sortbyonebits(@a) {
+  my %c = map {$_ => popcount64($_)}, @a;
+  return [sort {%c{$^a} <=> %c{$^b} || $^a <=> $^b}, @a];
+}
diff --git a/challenge-271/roger-bell-west/ruby/ch-1.rb b/challenge-271/roger-bell-west/ruby/ch-1.rb
new file mode 100755
index 0000000000..5394f83402
--- /dev/null
+++ b/challenge-271/roger-bell-west/ruby/ch-1.rb
@@ -0,0 +1,30 @@
+#! /usr/bin/ruby
+
+def maximumones(a)
+  ax = a.map { |r| r.sum }
+  am = ax.max
+  ax.each_with_index do |n, i|
+    if n == am then
+      return i + 1
+    end
+  end
+  return 0
+end
+
+require 'test/unit'
+
+class TestMaximumones < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(1, maximumones([[0, 1], [1, 0]]))
+  end
+
+  def test_ex2
+    assert_equal(2, maximumones([[0, 0, 0], [1, 0, 1]]))
+  end
+
+  def test_ex3
+    assert_equal(2, maximumones([[0, 0], [1, 1], [0, 0]]))
+  end
+
+end
diff --git a/challenge-271/roger-bell-west/ruby/ch-2.rb b/challenge-271/roger-bell-west/ruby/ch-2.rb
new file mode 100755
index 0000000000..7a2ac232cd
--- /dev/null
+++ b/challenge-271/roger-bell-west/ruby/ch-2.rb
@@ -0,0 +1,41 @@
+#! /usr/bin/ruby
+
+require "set"
+
+def popcount(x0)
+  x = x0
+  c = 0
+  while x > 0 do
+    x &= x - 1
+    c += 1
+  end
+  return c
+end
+
+def sortbyonebits(a)
+  c = Hash.new
+  Set.new(a).each do |n|
+    c[n] = popcount(n)
+  end
+  return a.sort do |aa, bb|
+    if c[aa] == c[bb] then
+      aa <=> bb
+    else
+      c[aa] <=> c[bb]
+    end
+  end
+end
+
+require 'test/unit'
+
+class TestSortbyonebits < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal([0, 1, 2, 4, 8, 3, 5, 6, 7], sortbyonebits([0, 1, 2, 3, 4, 5, 6, 7, 8]))
+  end
+
+  def test_ex2
+    assert_equal([64, 128, 256, 512, 1024], sortbyonebits([1024, 512, 256, 128, 64]))
+  end
+
+end
diff --git a/challenge-271/roger-bell-west/rust/ch-1.rs b/challenge-271/roger-bell-west/rust/ch-1.rs
new file mode 100755
index 0000000000..26bc2ddf04
--- /dev/null
+++ b/challenge-271/roger-bell-west/rust/ch-1.rs
@@ -0,0 +1,29 @@
+#! /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!(maximumones(vec![vec![0, 1], vec![1, 0]]), 1);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(maximumones(vec![vec![0, 0, 0], vec![1, 0, 1]]), 2);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(maximumones(vec![vec![0, 0], vec![1, 1], vec![0, 0]]), 2);
+}
+
+fn maximumones(a: Vec<Vec<u8>>) -> usize {
+    let ax = a.into_iter().map(|r| r.into_iter().sum()).collect::<Vec<u8>>();
+    let am = ax.clone().into_iter().max().unwrap();
+    ax.into_iter()
+        .enumerate()
+        .filter(|(_i, n)| *n == am)
+        .map(|(i, _n)| i)
+        .nth(0)
+        .unwrap()
+        + 1
+}
diff --git a/challenge-271/roger-bell-west/rust/ch-2.rs b/challenge-271/roger-bell-west/rust/ch-2.rs
new file mode 100755
index 0000000000..584541f454
--- /dev/null
+++ b/challenge-271/roger-bell-west/rust/ch-2.rs
@@ -0,0 +1,25 @@
+#! /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!(
+        sortbyonebits(vec![0, 1, 2, 3, 4, 5, 6, 7, 8]),
+        vec![0, 1, 2, 4, 8, 3, 5, 6, 7]
+    );
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(
+        sortbyonebits(vec![1024, 512, 256, 128, 64]),
+        vec![64, 128, 256, 512, 1024]
+    );
+}
+
+fn sortbyonebits(a0: Vec<u32>) -> Vec<u32> {
+    let mut a = a0.clone();
+    a.sort_unstable();
+    a.sort_by_cached_key(|x| x.count_ones());
+    a
+}
diff --git a/challenge-271/roger-bell-west/scala/ch-1.scala b/challenge-271/roger-bell-west/scala/ch-1.scala
new file mode 100644
index 0000000000..be6ee99025
--- /dev/null
+++ b/challenge-271/roger-bell-west/scala/ch-1.scala
@@ -0,0 +1,29 @@
+
+object Maximumones {
+  def maximumones(a: List[List[Int]]): Int = {
+    val ax = a.map(r => r.sum).toList
+    val am = ax.max
+    ax.indexOf(am) + 1
+  }
+  def main(args: Array[String]) {
+    if (maximumones(List(List(0, 1), List(1, 0))) == 1) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    print(" ")
+    if (maximumones(List(List(0, 0, 0), List(1, 0, 1))) == 2) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    print(" ")
+    if (maximumones(List(List(0, 0), List(1, 1), List(0, 0))) == 2) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    println("")
+
+  }
+}
diff --git a/challenge-271/roger-bell-west/scala/ch-2.scala b/challenge-271/roger-bell-west/scala/ch-2.scala
new file mode 100644
index 0000000000..f8856caefd
--- /dev/null
+++ b/challenge-271/roger-bell-west/scala/ch-2.scala
@@ -0,0 +1,41 @@
+
+object Sortbyonebits {
+  def popcount64(x0: Int): Int = {
+    val M1  = 0x5555555555555555L
+    val M2  = 0x3333333333333333L
+    val M4  = 0x0f0f0f0f0f0f0f0fL
+    val H01 = 0x0101010101010101L
+    var x = x0.toLong
+    x -= (x >> 1) & M1
+    x = (x & M2) + ((x >> 2) & M2)
+    x = (x + (x >> 4)) & M4
+    return ((x * H01) >> 56).toInt
+  }
+  def sortbyonebits(a: List[Int]): List[Int] = {
+    val c = a.map(n => n -> popcount64(n)).toMap
+    var b = a.toArray
+    b = b.sortWith((aa, bb) => {
+      if (c(aa) == c(bb)) {
+        aa < bb
+      } else {
+        c(aa) < c(bb)
+      }
+    })
+    return b.toList
+  }
+  def main(args: Array[String]) {
+    if (sortbyonebits(List(0, 1, 2, 3, 4, 5, 6, 7, 8)) == List(0, 1, 2, 4, 8, 3, 5, 6, 7)) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    print(" ")
+    if (sortbyonebits(List(1024, 512, 256, 128, 64)) == List(64, 128, 256, 512, 1024)) {
+      print("Pass")
+    } else {
+      print("Fail")
+    }
+    println("")
+
+  }
+}
diff --git a/challenge-271/roger-bell-west/tests.json b/challenge-271/roger-bell-west/tests.json
new file mode 100644
index 0000000000..b707e9057f
--- /dev/null
+++ b/challenge-271/roger-bell-west/tests.json
@@ -0,0 +1,38 @@
+{
+    "ch-1" : [
+        {
+            "function" : "maximumones",
+            "arguments" : [
+                [ 0, 1 ],
+                [ 1, 0 ]
+            ],
+            "result" : 1
+        },
+        {
+            "arguments" : [
+                [ 0, 0, 0 ],
+                [ 1, 0, 1 ]
+            ],
+            "result" : 2
+        },
+        {
+            "arguments" : [
+                [ 0, 0 ],
+                [ 1, 1 ],
+                [ 0, 0 ]
+            ],
+            "result" : 2
+        }
+    ],
+    "ch-2" : [
+        {
+            "function" : "sortbyonebits",
+            "arguments" : [ 0, 1, 2, 3, 4, 5, 6, 7, 8 ],
+            "result" : [ 0, 1, 2, 4, 8, 3, 5, 6, 7 ]
+        },
+        {
+            "arguments" : [ 1024, 512, 256, 128, 64 ],
+            "result" : [ 64, 128, 256, 512, 1024 ]
+        }
+    ]
+}
-- 
cgit