Merge pull request #6923 from Firedrake/rogerbw-challenge-187

Solutions for challenge #187

17 files changed, 1133 insertions, 0 deletions

diff --git a/challenge-187/roger-bell-west/javascript/ch-1.js b/challenge-187/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..e00346b98f
--- /dev/null
+++ b/challenge-187/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,54 @@
+#! /usr/bin/node
+
+"use strict"
+
+function s2date(ds) {
+    let dm = ds.split("-");
+    if (dm.length == 2) {
+        return Date.UTC(2022, parseInt(dm[1])-1, parseInt(dm[0]), 0, 0, 0, 0)/86400000;
+    }
+}
+
+function daystogether(a, b) {
+    let starts = [s2date(a[0]), s2date(b[0])];
+    starts.sort(function(a,b) {
+        return a-b;
+    });
+    let ends = [s2date(a[1]), s2date(b[1])];
+    ends.sort(function(a,b) {
+        return a-b;
+    });
+    if (ends[0] >= starts[1]) {
+        return ends[0]-starts[1]+1;
+    } else {
+        return 0;
+    }
+}
+
+if (daystogether(["12-01", "20-01"], ["15-01", "18-01"]) == 4) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (daystogether(["02-03", "12-03"], ["13-03", "14-03"]) == 0) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (daystogether(["02-03", "12-03"], ["11-03", "15-03"]) == 2) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (daystogether(["30-03", "05-04"], ["28-03", "02-04"]) == 4) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-187/roger-bell-west/javascript/ch-2.js b/challenge-187/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..67529e6246
--- /dev/null
+++ b/challenge-187/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,87 @@
+#! /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 magicaltriplets(a) {
+    let out = [];
+    let mv = 0;
+    for (let ai = 0; ai < a.length-2; ai++) {
+        for (let bi = ai+1; bi < a.length-1; bi++) {
+            for (let ci = bi+1; ci < a.length; ci++) {
+                if (a[ai] + a[bi] > a[ci] &&
+                    a[bi] + a[ci] > a[ai] &&
+                    a[ai] + a[ci] > a[bi]) {
+                    let v = a[ai] + a[bi] + a[ci];
+                    if (v > mv) {
+                        mv = v;
+                        out = [a[ai], a[bi], a[ci]];
+                    }
+                }
+            }
+        }
+    }
+    out.sort(function(a,b) {
+        return b-a;
+    });
+    return out;
+}
+
+if (deepEqual(magicaltriplets([1, 2, 3, 2]),
+              [3, 2, 2])) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (deepEqual(magicaltriplets([1, 3, 2]),
+              [])) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (deepEqual(magicaltriplets([1, 1, 2, 3]),
+              [])) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (deepEqual(magicaltriplets([2, 4, 3]),
+              [4, 3, 2])) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+
+process.stdout.write("\n");
diff --git a/challenge-187/roger-bell-west/kotlin/ch-1.kt b/challenge-187/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..299c4db50c
--- /dev/null
+++ b/challenge-187/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,49 @@
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
+import java.time.temporal.ChronoUnit
+
+fun s2date(ds: String): LocalDate {
+    val formatter = DateTimeFormatter.ofPattern("dd-MM-yyyy")
+    return LocalDate.parse(ds + "-2022", formatter)
+}
+
+fun daystogether(a: List<String>, b: List<String>): Int {
+    var starts = listOf(s2date(a[0]), s2date(b[0])).sorted()
+    var ends = listOf(s2date(a[1]), s2date(b[1])).sorted()
+    if (ends[0] >= starts[1]) {
+        return ChronoUnit.DAYS.between(starts[1], ends[0]).toInt()+1
+    } else {
+        return 0
+    }
+}
+
+fun main() {
+    if (daystogether(listOf("12-01", "20-01"), listOf("15-01", "18-01")) ==
+            4) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (daystogether(listOf("02-03", "12-03"), listOf("13-03", "14-03")) ==
+            0) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (daystogether(listOf("02-03", "12-03"), listOf("11-03", "15-03")) ==
+            2) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (daystogether(listOf("30-03", "05-04"), listOf("28-03", "02-04")) ==
+            4) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    println("")
+}
diff --git a/challenge-187/roger-bell-west/kotlin/ch-2.kt b/challenge-187/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..93fc98e9d7
--- /dev/null
+++ b/challenge-187/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,51 @@
+fun magicaltriplets(a: List<Int>): List<Int> {
+    var out = listOf<Int>()
+    var mv = 0
+    for (ai in 0..a.size-3) {
+        for (bi in ai+1..a.size-2) {
+            for (ci in bi+1..a.size-1) {
+                if (a[ai] + a[bi] > a[ci] &&
+                    a[bi] + a[ci] > a[ai] &&
+                    a[ai] + a[ci] > a[bi]) {
+                    var v = a[ai] + a[bi] + a[ci]
+                    if (v > mv) {
+                        mv = v
+                        out = listOf(a[ai], a[bi], a[ci])
+                    }
+                }
+            }
+        }
+    }
+    return out.sorted().reversed().toList()
+}
+
+fun main() {
+    if (magicaltriplets(listOf(1, 2, 3, 2)) ==
+            listOf(3, 2, 2)) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (magicaltriplets(listOf(1, 3, 2)) ==
+            listOf<Int>()) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (magicaltriplets(listOf(1, 1, 2, 3)) ==
+            listOf<Int>()) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (magicaltriplets(listOf(2, 4, 3)) ==
+            listOf(4, 3, 2)) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    println("")
+}
diff --git a/challenge-187/roger-bell-west/lua/ch-2.lua b/challenge-187/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..8aac5559d1
--- /dev/null
+++ b/challenge-187/roger-bell-west/lua/ch-2.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
+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
+
+  -- Check each key-value pair
+  -- We have to do this both ways in case we miss some.
+  -- TODO: Could probably be smarter and not check those we've 
+  -- already checked though!
+  for k1,v1 in pairs(t1) do
+    local v2 = t2[k1]
+    if( not recursive_compare(v1,v2) ) then return false end
+  end
+  for k2,v2 in pairs(t2) do
+    local v1 = t1[k2]
+    if( not recursive_compare(v1,v2) ) then return false end
+ end
+
+  return true  
+end
+-- by hookenz at
+-- https://stackoverflow.com/questions/9168058/how-to-dump-a-table-to-console
+function dump(o)
+   if type(o) == 'table' then
+      local s = '{ '
+      for k,v in pairs(o) do
+         if type(k) ~= 'number' then k = '"'..k..'"' end
+         s = s .. '['..k..'] = ' .. dump(v) .. ','
+      end
+      return s .. '} '
+   else
+      return tostring(o)
+   end
+end
+
+function magicaltriplets(a)
+   local out = {}
+   local mv = 0
+   for ai = 1,#a-2 do
+      for bi = ai+1,#a-1 do
+         for ci = bi+1,#a do
+            if a[ai] + a[bi] > a[ci] and
+               a[bi] + a[ci] > a[ai] and
+               a[ai] + a[ci] > a[bi] then
+               local v = a[ai] + a[bi] + a[ci]
+               if v > mv then
+                  mv = v
+                  out = {a[ai], a[bi], a[ci]}
+               end
+            end
+         end
+      end
+   end
+   table.sort(out, function (i,j) return j < i end)
+   return out
+end
+
+if (recursive_compare(magicaltriplets({1, 2, 3, 2}),
+                      {3, 2, 2})) then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+
+if (recursive_compare(magicaltriplets({1, 3, 2}),
+                      {})) then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+
+if (recursive_compare(magicaltriplets({1, 1, 2, 3}),
+                      {})) then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+
+if (recursive_compare(magicaltriplets({2, 4, 3}),
+                      {4, 3, 2})) then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+print("")
diff --git a/challenge-187/roger-bell-west/perl/ch-1.pl b/challenge-187/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..52ec4111b9
--- /dev/null
+++ b/challenge-187/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,45 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use DateTime;
+use DateTime::Format::Strptime;
+
+use Test::More tests => 4;
+
+is_deeply(daystogether(["12-01", "20-01"], ["15-01", "18-01"]),
+          4,
+          'example 1');
+
+is_deeply(daystogether(["02-03", "12-03"], ["13-03", "14-03"]),
+          0,
+          'example 2');
+
+is_deeply(daystogether(["02-03", "12-03"], ["11-03", "15-03"]),
+          2,
+          'example 3');
+
+is_deeply(daystogether(["30-03", "05-04"], ["28-03", "02-04"]),
+          4,
+          'example 4');
+
+sub daystogether($a,$b) {
+    my @starts = sort (s2date($a->[0]), s2date($b->[0]));
+    my @ends = sort (s2date($a->[1]), s2date($b->[1]));
+    if ($ends[0] > $starts[1]) {
+        return $ends[0]->delta_days($starts[1])->in_units('days')+1;
+    } else {
+        return 0;
+    }
+}
+
+sub s2date($ds) {
+  my $strp = DateTime::Format::Strptime->new(
+    pattern   => '%d-%m-%Y',
+    strict => 1,
+    time_zone => 'GMT',
+      );
+  return $strp->parse_datetime("$ds-2022");
+}
diff --git a/challenge-187/roger-bell-west/perl/ch-2.pl b/challenge-187/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..f0f55a7735
--- /dev/null
+++ b/challenge-187/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,43 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 4;
+
+use Algorithm::Combinatorics qw(combinations);
+
+is_deeply(magicaltriplets([1, 2, 3, 2]),
+          [3, 2, 2],
+          'example 1');
+
+is_deeply(magicaltriplets([1, 3, 2]),
+          [],
+          'example 2');
+
+is_deeply(magicaltriplets([1, 1, 2, 3]),
+          [],
+          'example 3');
+
+is_deeply(magicaltriplets([2, 4, 3]),
+          [4, 3, 2],
+          'example 4');
+
+sub magicaltriplets($a) {
+  my $out = [];
+  my $mv = 0;
+  my $iter = combinations($a, 3);
+  while (my $b = $iter->next) {
+    if ($b->[0] + $b->[1] > $b->[2] &&
+        $b->[1] + $b->[2] > $b->[0] &&
+        $b->[0] + $b->[2] > $b->[1]) {
+      my $v = $b->[0] + $b->[1] + $b->[2];
+      if ($v > $mv) {
+        $mv = $v;
+        $out = [$b->[0], $b->[1], $b->[2]];
+      }
+    }
+  }
+  return [reverse sort @{$out}];
+}
diff --git a/challenge-187/roger-bell-west/postscript/ch-1.ps b/challenge-187/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..3344baa22e
--- /dev/null
+++ b/challenge-187/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,155 @@
+%!PS
+
+% begin included library code
+% see https://github.com/Firedrake/postscript-libraries/
+/quicksort { % [ a c b ] -> [ a b c ]
+    1 dict begin
+    /arr exch def
+    0 arr length 1 sub quicksort.main
+    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 ge {
+                exit
+            } if
+        } loop
+        {
+            /j j 1 sub def
+            arr j get pivot 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
+
+/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
+
+/ymd2jd {
+    4 dict begin
+    aload pop
+    /d exch def
+    /m exch def
+    /y exch def
+    /mn m 14 sub 12 idiv def
+    y 4800 add mn add 1461 mul 4 idiv
+    mn 12 mul neg 2 sub m add 367 mul 12 idiv add
+    y 4900 add mn add 100 idiv 3 mul 4 idiv sub
+    d add
+    32075 sub
+    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
+
+
+% end included library code
+
+/daystogether {
+    2 dict begin
+    /starts 2 array def
+    /ends 2 array def
+    dup 0 get s2jd starts exch 1 exch put
+    1 get s2jd ends exch 1 exch put
+    dup 0 get s2jd starts exch 0 exch put
+    1 get s2jd ends exch 0 exch put
+    starts quicksort
+    ends quicksort
+    ends 0 get starts 1 get ge {
+        ends 0 get starts 1 get sub 1 add
+    } {
+        0
+    } ifelse
+    end
+} bind def
+
+/s2jd {
+    [ exch
+      2022 exch
+      dup
+      3 2 getinterval cvi exch
+      0 2 getinterval cvi
+    ]
+    ymd2jd
+} bind def
+
+(daystogether) test.start
+[ (12-01) (20-01) ] [ (15-01) (18-01) ] daystogether 4 eq test
+[ (02-03) (12-03) ] [ (13-03) (14-03) ] daystogether 0 eq test
+[ (02-03) (12-03) ] [ (11-03) (15-03) ] daystogether 2 eq test
+[ (30-03) (05-04) ] [ (28-03) (02-04) ] daystogether 4 eq test
+test.end
diff --git a/challenge-187/roger-bell-west/postscript/ch-2.ps b/challenge-187/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..b4f239de20
--- /dev/null
+++ b/challenge-187/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,222 @@
+%!PS
+
+% begin included library code
+% see https://github.com/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 { % [ a c b ] -> [ a b c ]
+    1 dict begin
+    /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 ge {
+                exit
+            } if
+        } loop
+        {
+            /j j 1 sub def
+            arr j get pivot 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
+
+/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 {
+    /test.count test.count 1 add def
+    {
+        /test.pass test.pass 1 add def
+    } {
+        ( ) print
+        test.count (....) cvs print
+        (-fail) print
+    } ifelse
+} bind def
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+
+% end included library code
+
+/reverse {
+    3 dict begin
+    /str exch def
+    str length 0 gt {
+        /temp str 0 get def
+        /i 0 def
+        str length 2 idiv {
+            /temp str i get def
+            str i str str length i sub 1 sub get put
+            str str length i sub 1 sub temp put
+            /i i 1 add def
+        } repeat
+    } if
+    str
+    end
+} bind def
+
+/magicaltriplets {
+    6 dict begin
+    /a exch def
+    /out 0 array def
+    /mv 0 def
+    0
+    1
+    a length 3 sub {
+        /ai exch def
+        ai 1 add
+        1
+        a length 2 sub {
+            /bi exch def
+            bi 1 add
+            1
+            a length 1 sub {
+                /ci exch def
+                a ai get a bi get add a ci get gt
+                a bi get a ci get add a ai get gt and
+                a ai get a ci get add a bi get gt and {
+                    /v a ai get a bi get add a ci get add def
+                    v mv gt {
+                        /mv v def
+                        /out [ a ai get a bi get a ci get ] def
+                    } if
+                } if
+            } for
+        } for
+    } for
+    out quicksort reverse
+    end
+} bind def
+
+(magicaltriplets) test.start
+[ 1 2 3 2 ] magicaltriplets [ 3 2 2 ] deepeq test
+[ 1 3 2 ] magicaltriplets [ ] deepeq test
+[ 1 1 2 3 ] magicaltriplets [ ] deepeq test
+[ 2 4 3 ] magicaltriplets [ 4 3 2 ] deepeq test
+test.end
diff --git a/challenge-187/roger-bell-west/python/ch-1.py b/challenge-187/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..b7be1cd5c4
--- /dev/null
+++ b/challenge-187/roger-bell-west/python/ch-1.py
@@ -0,0 +1,43 @@
+#! /usr/bin/python3
+
+import unittest
+
+from datetime import date, timedelta
+import re
+
+def s2date(ds):
+  dm = re.findall(r"\d+", ds)
+  if len(dm) == 2:
+    return date(2022, int(dm[1]), int(dm[0]))
+
+def daystogether(a, b):
+  starts = sorted([s2date(a[0]), s2date(b[0])])
+  ends = sorted([s2date(a[1]), s2date(b[1])])
+  if ends[0] >= starts[1]:
+    return (ends[0]-starts[1]).days+1
+  else:
+    return 0
+
+class TestDaystogether(unittest.TestCase):
+
+        def test_ex1(self):
+          self.assertEqual(daystogether(["12-01", "20-01"], ["15-01", "18-01"]),
+                           4,
+                           'example 1')
+
+        def test_ex2(self):
+          self.assertEqual(daystogether(["02-03", "12-03"], ["13-03", "14-03"]),
+                           0,
+                           'example 2')
+
+        def test_ex3(self):
+          self.assertEqual(daystogether(["02-03", "12-03"], ["11-03", "15-03"]),
+                           2,
+                           'example 3')
+
+        def test_ex4(self):
+          self.assertEqual(daystogether(["30-03", "05-04"], ["28-03", "02-04"]),
+                           4,
+                           'example 4')
+
+unittest.main()
diff --git a/challenge-187/roger-bell-west/python/ch-2.py b/challenge-187/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..0686ce96cd
--- /dev/null
+++ b/challenge-187/roger-bell-west/python/ch-2.py
@@ -0,0 +1,40 @@
+#! /usr/bin/python3
+
+import unittest
+
+from itertools import combinations
+
+def magicaltriplets(a):
+  out = []
+  mv = 0
+  for b in combinations(a, 3):
+    if b[0] + b[1] > b[2] and b[1] + b[2] > b[0] and b[0] + b[2] > b[1]:
+       v = sum(b)
+       if v > mv:
+         mv = v
+         out = b
+  return list(reversed(sorted(out)))
+
+class TestMagicaltriplets(unittest.TestCase):
+
+        def test_ex1(self):
+          self.assertEqual(magicaltriplets([1, 2, 3, 2]),
+                           [3, 2, 2],
+                           'example 1')
+
+        def test_ex2(self):
+          self.assertEqual(magicaltriplets([1, 3, 2]),
+                           [],
+                           'example 2')
+
+        def test_ex3(self):
+          self.assertEqual(magicaltriplets([1, 1, 2, 3]),
+                           [],
+                           'example 3')
+
+        def test_ex4(self):
+          self.assertEqual(magicaltriplets([2, 4, 3]),
+                           [4, 3, 2],
+                           'example 4')
+
+unittest.main()
diff --git a/challenge-187/roger-bell-west/raku/ch-1.p6 b/challenge-187/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..f90728fc46
--- /dev/null
+++ b/challenge-187/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,40 @@
+#! /usr/bin/perl6
+
+use Test;
+
+plan 4;
+
+is-deeply(daystogether(["12-01", "20-01"], ["15-01", "18-01"]),
+          4,
+          'example 1');
+
+is-deeply(daystogether(["02-03", "12-03"], ["13-03", "14-03"]),
+          0,
+          'example 2');
+
+is-deeply(daystogether(["02-03", "12-03"], ["11-03", "15-03"]),
+          2,
+          'example 3');
+
+is-deeply(daystogether(["30-03", "05-04"], ["28-03", "02-04"]),
+          4,
+          'example 4');
+
+sub daystogether(@a,@b) {
+    my @starts = [s2date(@a[0]), s2date(@b[0])].sort;
+    my @ends = [s2date(@a[1]), s2date(@b[1])].sort;
+    if (@ends[0] > @starts[1]) {
+        return @ends[0]-@starts[1]+1;
+    } else {
+        return 0;
+    }
+}
+
+sub s2date($ds) {
+    if ($ds ~~ /^(\d+)\-(\d+)$/) {
+        return Date.new(year => 2022,
+                        month => $1,
+                        day => $0);
+    }
+    die "$ds is not a recognisable date\n";
+}
diff --git a/challenge-187/roger-bell-west/raku/ch-2.p6 b/challenge-187/roger-bell-west/raku/ch-2.p6
new file mode 100755
index 0000000000..805ed2f684
--- /dev/null
+++ b/challenge-187/roger-bell-west/raku/ch-2.p6
@@ -0,0 +1,38 @@
+#! /usr/bin/perl6
+
+use Test;
+
+plan 4;
+
+is-deeply(magicaltriplets([1, 2, 3, 2]),
+          [3, 2, 2],
+          'example 1');
+
+is-deeply(magicaltriplets([1, 3, 2]),
+          [],
+          'example 2');
+
+is-deeply(magicaltriplets([1, 1, 2, 3]),
+          [],
+          'example 3');
+
+is-deeply(magicaltriplets([2, 4, 3]),
+          [4, 3, 2],
+          'example 4');
+
+sub magicaltriplets(@a) {
+    my @out;
+    my $mv = 0;
+    for @a.combinations(3) -> @b {
+        if (@b[0] + @b[1] > @b[2] &&
+            @b[1] + @b[2] > @b[0] &&
+            @b[0] + @b[2] > @b[1]) {
+            my $v = @b.sum;
+            if ($v > $mv) {
+                $mv = $v;
+                @out = @b;
+            }
+        }
+    }
+    return Array(@out.sort.reverse);
+}
diff --git a/challenge-187/roger-bell-west/ruby/ch-1.rb b/challenge-187/roger-bell-west/ruby/ch-1.rb
new file mode 100755
index 0000000000..fa83e9dad2
--- /dev/null
+++ b/challenge-187/roger-bell-west/ruby/ch-1.rb