Merge pull request #9267 from Firedrake/rogerbw-challenge-248

RogerBW solutions for challenge no. 248

21 files changed, 1155 insertions, 0 deletions

diff --git a/challenge-248/roger-bell-west/javascript/ch-1.js b/challenge-248/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..5a6743bd17
--- /dev/null
+++ b/challenge-248/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,72 @@
+#! /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 shortestdistance(a, c) {
+    let q = [];
+    let i = 0;
+    while (i >= 0) {
+        const p = a.indexOf(c, i);
+        if (p >= 0) {
+            q.push([p, 0]);
+            i = p + 1;
+        } else {
+            i = -1;
+        }
+    }
+    const invalid = a.length + 1;
+    let out = Array(a.length).fill().map((element, index) => invalid);
+    while (q.length > 0) {
+        let [i, v] = q.shift();
+        if (out[i] == invalid) {
+            out[i] = v;
+            if (i > 0) {
+                q.push([i - 1, v + 1]);
+            }
+            if (i < a.length - 1) {
+                q.push([i + 1, v + 1]);
+            }
+        }
+    }
+    return out;
+}
+
+if (deepEqual(shortestdistance('loveleetcode', 'e'), [3, 2, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(shortestdistance('aaab', 'b'), [3, 2, 1, 0])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-248/roger-bell-west/javascript/ch-2.js b/challenge-248/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..268838ce20
--- /dev/null
+++ b/challenge-248/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,61 @@
+#! /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 submatrixsum(a) {
+    let out = [];
+    for (let y = 0; y < a.length - 1; y++) {
+        let row = [];
+        for (let x = 0; x < a[y].length - 1; x++) {
+            let s = 0;
+            for (let ya = y; ya <= y + 1; ya++) {
+                for (let xa = x; xa <= x + 1; xa++) {
+                    s += a[ya][xa];
+                }
+            }
+            row.push(s);
+        }
+        out.push(row);
+    }
+    return out;
+}
+
+if (deepEqual(submatrixsum([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]), [[14, 18, 22], [30, 34, 38]])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+if (deepEqual(submatrixsum([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]), [[2, 1, 0], [1, 2, 1], [0, 1, 2]])) {
+  process.stdout.write("Pass");
+} else {
+  process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-248/roger-bell-west/kotlin/ch-1.kt b/challenge-248/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..f1d671b922
--- /dev/null
+++ b/challenge-248/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,47 @@
+fun shortestdistance(a: String, c: Char): List<Int> {
+    var q = ArrayDeque<Pair<Int, Int>>()
+    var j = 0
+    while (j >= 0) {
+        val p = a.indexOf(c, j)
+        if (p >= 0) {
+            q.add(Pair(p, 0))
+            j = p + 1
+        } else {
+            j = -1
+        }
+    }
+    val invalid = a.length + 1
+    var out = ArrayList(generateSequence(invalid) { invalid }.take(a.length).toList())
+    while (q.size > 0) {
+        val pp = q.removeFirst()
+        val i = pp.first
+        val v = pp.second
+        if (out[i] == invalid) {
+            out[i] = v
+            if (i > 0) {
+                q.add(Pair(i - 1, v + 1))
+            }
+            if (i < a.length - 1) {
+                q.add(Pair(i + 1, v + 1))
+            }
+        }
+    }
+    return out.toList()
+}
+
+    fun main() {
+
+    if (shortestdistance("loveleetcode", 'e') == listOf(3, 2, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (shortestdistance("aaab", 'b') == listOf(3, 2, 1, 0)) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-248/roger-bell-west/kotlin/ch-2.kt b/challenge-248/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..21d8e42bbb
--- /dev/null
+++ b/challenge-248/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,34 @@
+fun submatrixsum(a: List<List<Int>>): List<List<Int>> {
+    var out = ArrayList<List<Int>>()
+    for (y in 0 .. a.size - 2) {
+        var row = ArrayList<Int>()
+        for (x in 0 .. a[0].size - 2) {
+            var s = 0
+            for (ya in y .. y + 1) {
+                for (xa in x .. x + 1) {
+                    s += a[ya][xa]
+                }
+            }
+            row.add(s)
+        }
+        out.add(row.toList())
+    }
+    return out.toList()
+}
+
+fun main() {
+
+    if (submatrixsum(listOf(listOf(1, 2, 3, 4), listOf(5, 6, 7, 8), listOf(9, 10, 11, 12))) == listOf(listOf(14, 18, 22), listOf(30, 34, 38))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    print(" ")
+    if (submatrixsum(listOf(listOf(1, 0, 0, 0), listOf(0, 1, 0, 0), listOf(0, 0, 1, 0), listOf(0, 0, 0, 1))) == listOf(listOf(2, 1, 0), listOf(1, 2, 1), listOf(0, 1, 2))) {
+        print("Pass")
+    } else {
+        print("Fail")
+    }
+    println("")
+
+}
diff --git a/challenge-248/roger-bell-west/lua/ch-1.lua b/challenge-248/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..fac8c639ae
--- /dev/null
+++ b/challenge-248/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,77 @@
+#! /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 shortestdistance(a, c)
+   local q = {}
+   local i = 1
+   while i >= 1 do
+      local p = string.find(a, c, i, true)
+      if p then
+         table.insert(q, {p, 0})
+         i = p + 1
+      else
+         i = 0
+      end
+   end
+   local invalid = #a + 1
+   local out = {}
+   for i = 1, #a do
+      out[i] = invalid
+   end
+   while (#q > 0) do
+      local i, v = table.remove(q, 1)
+      if out[i] == invalid then
+         out[i] = v
+         if i > 1 then
+            table.insert(q, {i - 1, v + 1})
+         end
+         if i < #a then
+            table.insert(q, {i + 1, v + 1})
+         end
+      end
+   end
+   return out
+end
+
+if recursive_compare(shortestdistance("loveleetcode", "e"), {3, 2, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(shortestdistance("aaab", "b"), {3, 2, 1, 0}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-248/roger-bell-west/lua/ch-2.lua b/challenge-248/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..8cafa55155
--- /dev/null
+++ b/challenge-248/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,63 @@
+#! /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 submatrixsum(a)
+   local out = {}
+   for x = 1, #a - 1 do
+      local row = {}
+      for y = 1, #(a[x])-1 do
+         local s = 0
+         for ya = y, y + 1 do
+            for xa = x, x + 1 do
+               s = s + a[y][x]
+            end
+         end
+         table.insert(row, s)
+      end
+      table.insert(out, row)
+   end
+   return out
+end
+
+if recursive_compare(submatrixsum({{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}}), {{14, 18, 22}, {30, 34, 38}}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(submatrixsum({{1, 0, 0, 0}, {0, 1, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1}}), {{2, 1, 0}, {1, 2, 1}, {0, 1, 2}}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+
diff --git a/challenge-248/roger-bell-west/perl/ch-1.pl b/challenge-248/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..57e51877bf
--- /dev/null
+++ b/challenge-248/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,39 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 2;
+
+is_deeply(shortestdistance('loveleetcode', 'e'), [3, 2, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0], 'example 1');
+is_deeply(shortestdistance('aaab', 'b'), [3, 2, 1, 0], 'example 2');
+
+sub shortestdistance($a, $c) {
+  my @q;
+  my $i = 0;
+  while ($i >= 0) {
+    my $p = index($a, $c, $i);
+    if ($p > -1) {
+      push @q, [$p, 0];
+      $i = $p + 1;
+    } else {
+      $i = -1;
+    }
+  }
+  my $invalid = length($a) + 1;
+  my @out = ($invalid) x length($a);
+  while (scalar @q) {
+    my ($i, $v) = @{shift @q};
+    if ($out[$i] == $invalid) {
+      $out[$i] = $v;
+      if ($i > 0) {
+        push(@q, [$i - 1, $v + 1]);
+      }
+      if ($i < length($a) - 1) {
+        push(@q, [$i + 1, $v + 1]);
+      }
+    }
+  }
+  return \@out;
+}
diff --git a/challenge-248/roger-bell-west/perl/ch-2.pl b/challenge-248/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..0c958525c8
--- /dev/null
+++ b/challenge-248/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,28 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 2;
+
+is_deeply(submatrixsum([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]), [[14, 18, 22], [30, 34, 38]], 'example 1');
+is_deeply(submatrixsum([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]), [[2, 1, 0], [1, 2, 1], [0, 1, 2]], 'example 2');
+
+sub submatrixsum($a) {
+  my @out;
+  foreach my $y (0 .. $#{$a} - 1) {
+    my @row;
+    foreach my $x (0 .. $#{$a->[$y]} - 1) {
+      my $s = 0;
+      foreach my $ya ($y, $y + 1) {
+        foreach my $xa ($x, $x + 1) {
+          $s += $a->[$ya][$xa];
+        }
+      }
+      push @row, $s;
+    }
+    push @out, \@row;
+  }
+  return \@out;
+}
diff --git a/challenge-248/roger-bell-west/postscript/ch-1.ps b/challenge-248/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..0876cff3be
--- /dev/null
+++ b/challenge-248/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,179 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/enumerate.array {
+    1 dict begin
+    /a exch def
+    [
+      0 1 a length 1 sub {
+          [ exch dup a exch get ]
+      } for
+    ]
+    end
+} bind def
+
+/apop.left { % [a b c] -> [b c] a
+    dup 0 get exch
+    [ exch aload length -1 roll pop ] exch
+} 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
+
+/filter { % array proc(bool) -> array
+    1 dict begin
+    /p exch def
+    [ exch
+      {
+          dup p not
+          {
+              pop
+          } if
+      } forall
+    ]
+    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
+
+/map { % array proc -> array
+    2 dict begin
+    /p exch def
+    [ exch
+      {
+          p
+      } forall
+    ]
+    end
+} bind def
+
+/apush.right { % [a b] c -> [a b c]
+    exch
+    [ exch aload length 2 add -1 roll ]
+} bind def
+
+/s2a {
+    [ exch { } forall ]
+} bind def
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+
+% end included library code
+
+/shortestdistance {
+    0 dict begin
+    /c exch s2a 0 get def
+    /a exch s2a def
+    /i 0 def
+    /q a enumerate.array { 1 get c eq } filter { 0 get [ exch 0 ] } map def
+    /invalid a length 1 add def
+    /out [ a length { invalid } repeat ] def
+    {
+        q length 0 eq {
+            exit
+        } if
+        q apop.left
+        aload pop /v exch def /i exch def
+        /q exch def
+        out i get invalid eq {
+            out i v put
+            i 0 gt {
+                /q q [ i 1 sub v 1 add ] apush.right def
+            } if
+            i a length 1 sub lt {
+                /q q [ i 1 add v 1 add ] apush.right def
+            } if
+        } if
+    } loop
+    out
+    end
+} bind def
+
+(shortestdistance) test.start
+(loveleetcode) (e) shortestdistance [3 2 1 0 1 0 0 1 2 2 1 0] deepeq test
+(aaab) (b) shortestdistance [3 2 1 0] deepeq test
+test.end
diff --git a/challenge-248/roger-bell-west/postscript/ch-2.ps b/challenge-248/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..a96973fb7c
--- /dev/null
+++ b/challenge-248/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,125 @@
+%!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
+
+/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
+
+/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
+
+/submatrixsum {
+    0 dict begin
+    /a exch def
+    [
+        0 1 a length 2 sub {
+            /y exch def
+            [
+                0 1 a y get length 2 sub {
+                    /x exch def
+                    /s 0 def
+                    [ y dup 1 add ] {
+                        /ya exch def
+                        [ x dup 1 add ] {
+                            /xa exch def
+                            /s s a ya get xa get add def
+                        } forall
+                    } forall
+                    s
+                } for
+            ]
+        } for
+    ]
+    end
+} bind def
+
+(submatrixsum) test.start
+[[1 2 3 4] [5 6 7 8] [9 10 11 12]] submatrixsum [[14 18 22] [30 34 38]] deepeq test
+[[1 0 0 0] [0 1 0 0] [0 0 1 0] [0 0 0 1]] submatrixsum [[2 1 0] [1 2 1] [0 1 2]] deepeq test
+test.end
diff --git a/challenge-248/roger-bell-west/python/ch-1.py b/challenge-248/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..b1a4c7491f
--- /dev/null
+++ b/challenge-248/roger-bell-west/python/ch-1.py
@@ -0,0 +1,37 @@
+#! /usr/bin/python3
+
+from collections import deque
+
+def shortestdistance(a, c):
+  q = deque()
+  i = 0
+  while i >= 0:
+    p = a.find(c, i)
+    if p >= 0:
+      q.append([p, 0])
+      i = p + 1
+    else:
+      i = -1
+  invalid = len(a) + 1
+  out = len(a) * [invalid]
+  while len(q) > 0:
+    i, v = q.popleft()
+    if out[i] == invalid:
+      out[i] = v
+      if i > 0:
+        q.append([i - 1, v + 1])
+      if i < len(a) - 1:
+        q.append([i + 1, v + 1])
+  return out
+
+import unittest
+
+class TestShortestdistance(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(shortestdistance("loveleetcode", "e"), [3, 2, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0], 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(shortestdistance("aaab", "b"), [3, 2, 1, 0], 'example 2')
+
+unittest.main()
diff --git a/challenge-248/roger-bell-west/python/ch-2.py b/challenge-248/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..5d21ce17dd
--- /dev/null
+++ b/challenge-248/roger-bell-west/python/ch-2.py
@@ -0,0 +1,26 @@
+#! /usr/bin/python3
+
+def submatrixsum(a):
+  out = []
+  for y in range(len(a) - 1):
+    row = []
+    for x in range(len(a[y]) - 1):
+      s = 0
+      for ya in [y, y+1]:
+        for xa in [x, x+1]:
+          s += a[ya][xa]
+      row.append(s)
+    out.append(row)
+  return out    
+
+import unittest
+
+class TestSubmatrixsum(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(submatrixsum([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]), [[14, 18, 22], [30, 34, 38]], 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(submatrixsum([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]), [[2, 1, 0], [1, 2, 1], [0, 1, 2]], 'example 2')
+
+unittest.main()
diff --git a/challenge-248/roger-bell-west/raku/ch-1.p6 b/challenge-248/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..dc7b130510
--- /dev/null
+++ b/challenge-248/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,36 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 2;
+
+is-deeply(shortestdistance('loveleetcode', 'e'), [3, 2, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0], 'example 1');
+is-deeply(shortestdistance('aaab', 'b'), [3, 2, 1, 0], 'example 2');
+
+sub shortestdistance($a, $c) {
+    my @q;
+    my $i = 0;
+    while (True) {
+        with ($a.index($c, $i)) {
+            @q.push(($_, 0));
+            $i = $_ + 1;
+        } else {
+            last;
+        }
+    }
+    my $invalid = $a.chars + 1;
+    my @out = $invalid xx $a.chars();
+    while (@q.elems > 0) {
+        my ($i, $v) = @q.shift;
+        if (@out[$i] == $invalid) {
+            @out[$i] = $v;
+            if ($i > 0) {
+                @q.push(($i - 1, $v + 1));
+            }
+            if ($i < $a.chars - 1) {
+                @q.push(($i + 1, $v + 1));
+            }
+        }
+    }
+    return @out;
+}
diff --git a/challenge-248/roger-bell-west/raku/ch-2.p6 b/challenge-248/roger-bell-west/raku/ch-2.p6
new file mode 100755
index 0000000000..0dade3df2e
--- /dev/null
+++ b/challenge-248/roger-bell-west/raku/ch-2.p6
@@ -0,0 +1,26 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 2;
+
+is-deeply(submatrixsum([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]), [[14, 18, 22], [30, 34, 38]], 'example 1');
+is-deeply(submatrixsum([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]), [[2, 1, 0], [1, 2, 1], [0, 1, 2]], 'example 2');
+
+sub submatrixsum(@a) {
+    my @out;
+    for (0 .. @a.end - 1) -> $y {
+        my @row;
+        for (0 .. @a[$y].end - 1) -> $x {
+            my $s = 0;
+            for ($y .. $y + 1) -> $ya {
+                for ($x .. $x + 1) -> $xa {
+                    $s += @a[$ya][$xa];
+                }
+            }
+            @row.push($s);
+        }
+        @out.push(@row)
+    }
+    return @out;
+}
diff --git a/challenge-248/roger-bell-west/ruby/ch-1.rb b/challenge-248/roger-bell-west/ruby/ch-1.rb
new file mode 100755
index 0000000000..9d54ab7123
--- /dev/null
+++ b/challenge-248/roger-bell-west/ruby/ch-1.rb
@@ -0,0 +1,44 @@
+#! /usr/bin/ruby
+
+def shortestdistance(a, c)
+  q = []
+  i = 0
+  while i >= 0 do
+    p = a.index(c, i)
+    if p then
+      q.push([p, 0])
+      i = p + 1
+    else
+      i = -1
+    end
+  end
+  invalid = a.length + 1
+  out = Array.new(a.length) {|i| invalid}
+  while q.length > 0 do
+    i, v = q.shift
+    if out[i] == invalid then
+      out[i] = v
+      if i > 0 then
+        q.push([i - 1, v + 1])
+      end
+      if i < a.length - 1 then
+        q.push([i + 1, v + 1])
+      end
+    end
+  end
+  return out
+end
+
+require 'test/unit'
+
+class TestShortestdistance < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal([3, 2, 1, 0, 1, 0,