Solutions for challenge #194

18 files changed, 876 insertions, 0 deletions

diff --git a/challenge-194/roger-bell-west/javascript/ch-1.js b/challenge-194/roger-bell-west/javascript/ch-1.js
new file mode 100755
index 0000000000..eed8a48113
--- /dev/null
+++ b/challenge-194/roger-bell-west/javascript/ch-1.js
@@ -0,0 +1,65 @@
+#! /usr/bin/node
+
+"use strict"
+
+function digitalclock(hhmm) {
+    let i = hhmm.indexOf("?");
+    if (i == 0) {
+        if (hhmm.charAt(1) <= "3") {
+            return 2;
+        }
+        return 1;
+    } else if (i == 1) {
+        if (hhmm.charAt(0) < "2") {
+            return 9;
+        }
+        return 3;
+    } else if (i == 3) {
+        return 5;
+    } else if (i == 4) {
+        return 9;
+    }
+    return 0;
+}
+
+if (digitalclock("?5:00") == 1) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (digitalclock("?3:00") == 2) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (digitalclock("1?:00") == 9) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (digitalclock("2?:00") == 3) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (digitalclock("12:?5") == 5) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (digitalclock("12:5?") == 9) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-194/roger-bell-west/javascript/ch-2.js b/challenge-194/roger-bell-west/javascript/ch-2.js
new file mode 100755
index 0000000000..29be8475e4
--- /dev/null
+++ b/challenge-194/roger-bell-west/javascript/ch-2.js
@@ -0,0 +1,41 @@
+#! /usr/bin/node
+
+"use strict"
+
+function frequencyequalizer(s) {
+    let f = new Map();
+    for (let c of s.split("")) {
+        if (f.has(c)) {
+            f.set(c, f.get(c) + 1);
+        } else {
+            f.set(c, 1);
+        }
+    }
+    let v = [...f.values()].sort();
+    if (v[0] == v[v.length-2] &&
+        v[0] + 1 == v[v.length-1]) {
+        return true;
+    }
+    return false;
+}
+
+if (frequencyequalizer("abbc")) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (frequencyequalizer("xyzyyxz")) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write(" ");
+
+if (!frequencyequalizer("xzxz")) {
+    process.stdout.write("Pass");
+} else {
+    process.stdout.write("FAIL");
+}
+process.stdout.write("\n");
diff --git a/challenge-194/roger-bell-west/kotlin/ch-1.kt b/challenge-194/roger-bell-west/kotlin/ch-1.kt
new file mode 100644
index 0000000000..937a812fa1
--- /dev/null
+++ b/challenge-194/roger-bell-west/kotlin/ch-1.kt
@@ -0,0 +1,58 @@
+fun digitalclock(hhmm: String): Int {
+    val i = hhmm.indexOf("?")
+    if (i == 0) {
+        if (hhmm[1] <= '3') {
+            return 2;
+        }
+        return 1;
+    } else if (i == 1) {
+        if (hhmm[0] < '2') {
+            return 9;
+        }
+        return 3;
+    } else if (i == 3) {
+        return 5;
+    } else if (i == 4) {
+        return 9;
+    }
+    return 0;
+}
+
+fun main() {
+    if (digitalclock("?5:00") == 1) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (digitalclock("?3:00") == 2) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (digitalclock("1?:00") == 9) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (digitalclock("2?:00") == 3) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (digitalclock("12:?5") == 5) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")
+    if (digitalclock("12:5?") == 9) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    println("")
+}
diff --git a/challenge-194/roger-bell-west/kotlin/ch-2.kt b/challenge-194/roger-bell-west/kotlin/ch-2.kt
new file mode 100644
index 0000000000..83c49d420b
--- /dev/null
+++ b/challenge-194/roger-bell-west/kotlin/ch-2.kt
@@ -0,0 +1,34 @@
+fun frequencyequalizer(s: String): Boolean {
+    var f = mutableMapOf<Char, Int>()
+    for (c in s) {
+        var l = f.getOrDefault(c, 0);
+        f.set(c, l + 1);
+    }
+    val v = f.values.sorted()
+    if (v[0] == v[v.size - 2] &&
+        v[0] + 1 == v[v.size - 1]) {
+        return true
+    }
+    return false
+}
+
+fun main() {
+    if (frequencyequalizer("abbc")) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")   
+    if (frequencyequalizer("xyzyyxz")) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    print(" ")   
+    if (!frequencyequalizer("xzxz")) {
+        print("Pass")
+    } else {
+        print("FAIL")
+    }
+    println("")
+}
diff --git a/challenge-194/roger-bell-west/lua/ch-1.lua b/challenge-194/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..00246aa4c5
--- /dev/null
+++ b/challenge-194/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,58 @@
+#! /usr/bin/lua
+
+function digitalclock(hhmm)
+   local i = string.find(hhmm, "%?")
+   if i == 1 then
+      if string.sub(hhmm, 2, 2) <= "3" then
+         return 2
+      end
+      return 1
+   elseif i == 2 then
+      if string.sub(hhmm, 1, 1) < "2" then
+         return 9
+      end
+      return 3
+   elseif i == 4 then
+      return 5
+   elseif i == 5 then
+      return 9
+   end
+   return 0
+end
+
+if digitalclock("?5:00") == 1 then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+if digitalclock("?3:00") == 2 then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+if digitalclock("1?:00") == 9 then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+if digitalclock("2?:00") == 3 then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+if digitalclock("12:?5") == 5 then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+if digitalclock("12:5?") == 9 then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+print("")
diff --git a/challenge-194/roger-bell-west/lua/ch-2.lua b/challenge-194/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..c300e15325
--- /dev/null
+++ b/challenge-194/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,43 @@
+#! /usr/bin/lua
+
+function frequencyequalizer(s)
+   local f = {}
+   for c in string.gmatch(s, ".") do
+      if f[c] == nil then
+         f[c] = 1
+      else
+         f[c] = f[c] + 1
+      end
+   end
+   local sk = {}
+   for i, v in pairs(f) do
+      table.insert(sk, v)
+   end
+   table.sort(sk)
+   if sk[1] == sk[#sk-1] and
+      sk[1] + 1 == sk[#sk] then
+      return true
+   end
+   return false
+end
+
+if frequencyequalizer("abbc") == true then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+
+if frequencyequalizer("xyzyyxz") == true then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+
+if frequencyequalizer("xzxz") == false then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+print("")
diff --git a/challenge-194/roger-bell-west/perl/ch-1.pl b/challenge-194/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..d146ee8bfb
--- /dev/null
+++ b/challenge-194/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,34 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 6;
+
+is(digitalclock("?5:00"), 1, 'example 1');
+is(digitalclock("?3:00"), 2, 'example 2');
+is(digitalclock("1?:00"), 9, 'example 3');
+is(digitalclock("2?:00"), 3, 'example 4');
+is(digitalclock("12:?5"), 5, 'example 5');
+is(digitalclock("12:5?"), 9, 'example 6');
+
+sub digitalclock($hhmm) {
+  my $i = index($hhmm, '?');
+  if ($i == 0) {
+    if (substr($hhmm, 1, 1) le "3") {
+      return 2;
+    }
+    return 1;
+  } elsif ($i == 1) {
+    if (substr($hhmm, 0, 1) lt "2") {
+      return 9;
+    }
+    return 3;
+  } elsif ($i == 3) {
+    return 5;
+  } elsif ($i == 4) {
+    return 9;
+  }
+  return 0;
+}
diff --git a/challenge-194/roger-bell-west/perl/ch-2.pl b/challenge-194/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..54bd487266
--- /dev/null
+++ b/challenge-194/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,24 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 3;
+
+is(frequencyequalizer("abbc"), 1, 'example 1');
+is(frequencyequalizer("xyzyyxz"), 1, 'example 2');
+is(frequencyequalizer("xzxz"), 0, 'example 3');
+
+sub frequencyequalizer($s) {
+  my %f;
+  foreach my $c (split '',$s) {
+    $f{$c}++;
+  }
+  my @v = sort values %f;
+  if ($v[0] == $v[-2] &&
+      $v[0] + 1 == $v[-1]) {
+    return 1;
+  }
+  return 0;
+}
diff --git a/challenge-194/roger-bell-west/postscript/ch-1.ps b/challenge-194/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..220a077dfc
--- /dev/null
+++ b/challenge-194/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,84 @@
+%!PS
+
+% begin included library code
+% see https://github.com/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
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} 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
+
+
+% end included library code
+
+/digitalclock {
+    2 dict begin
+    /hhmm exch def
+    hhmm (?) search {
+        length /i exch def pop pop
+        1 {
+            i 0 eq {
+                hhmm 1 get 51 le {
+                    2
+                } {
+                    1
+                } ifelse
+                exit
+            } if
+            i 1 eq {
+                hhmm 0 get 50 lt {
+                    9
+                } {
+                    3
+                } ifelse
+                exit
+            } if
+            i 3 eq {
+                5
+                exit
+            } if
+            i 4 eq {
+                9
+                exit
+            } if
+            0
+        } repeat
+    } {
+        pop 0
+    } ifelse
+    end
+} bind def
+
+(digitalclock) test.start
+(?5:00) digitalclock 1 eq test
+(?3:00) digitalclock 2 eq test
+(1?:00) digitalclock 9 eq test
+(2?:00) digitalclock 3 eq test
+(12:?5) digitalclock 5 eq test
+(12:5?) digitalclock 9 eq test
+test.end
diff --git a/challenge-194/roger-bell-west/postscript/ch-2.ps b/challenge-194/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..a368c8464a
--- /dev/null
+++ b/challenge-194/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,141 @@
+%!PS
+
+% begin included library code
+% see https://github.com/Firedrake/postscript-libraries/
+/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 {
+    /test.count test.count 1 add def
+    {
+        /test.pass test.pass 1 add def
+    } {
+        ( ) print
+        test.count (....) cvs print
+        (-fail) print
+    } ifelse
+} 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.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 { % [ 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
+
+/test.end {
+    ( ) print
+    test.count 0 gt {
+        (Passed ) print
+        test.pass (...) cvs print
+        (/) print
+        test.count (...) cvs print
+        ( \() print
+        test.pass 100 mul test.count idiv (...) cvs print
+        (%\)) print
+        (\r\n) print
+    } if
+} bind def
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+/values { % dict -> array of dict values
+    [ exch
+      {
+          exch pop
+      } forall
+    ]
+} bind def
+
+
+% end included library code
+
+/frequencyequalizer {
+    2 dict begin
+    /f 0 dict def
+    {
+        dup f exch known {
+            dup f exch get 1 add f 3 1 roll put
+        } {
+            f exch 1 put
+        } ifelse
+    } forall
+    /v f values quicksort def
+    v 0 get v v length 2 sub get eq
+    v 0 get 1 add v v length 1 sub get eq and {
+        true
+    } {
+        false
+    } ifelse
+    end
+} bind def
+
+(frequencyequalizer) test.start
+(abbc) frequencyequalizer test
+(xyzyyxz) frequencyequalizer test
+(xzxz) frequencyequalizer not test
+test.end
diff --git a/challenge-194/roger-bell-west/python/ch-1.py b/challenge-194/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..68f2aaa298
--- /dev/null
+++ b/challenge-194/roger-bell-west/python/ch-1.py
@@ -0,0 +1,41 @@
+#! /usr/bin/python3
+
+import unittest
+
+def digitalclock(hhmm):
+  i = hhmm.find("?")
+  if i == 0:
+    if hhmm[1] <= "3":
+      return 2
+    return 1
+  elif i == 1:
+    if hhmm[0] < "2":
+      return 9
+    return 3
+  elif i == 3:
+    return 5
+  elif i == 4:
+    return 9
+  return 0
+
+class TestDigitalclock(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(digitalclock("?5:00"), 1, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(digitalclock("?3:00"), 2, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(digitalclock("1?:00"), 9, 'example 3')
+
+  def test_ex4(self):
+    self.assertEqual(digitalclock("2?:00"), 3, 'example 4')
+
+  def test_ex5(self):
+    self.assertEqual(digitalclock("12:?5"), 5, 'example 5')
+
+  def test_ex6(self):
+    self.assertEqual(digitalclock("12:5?"), 9, 'example 6')
+
+unittest.main()
diff --git a/challenge-194/roger-bell-west/python/ch-2.py b/challenge-194/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..568621d839
--- /dev/null
+++ b/challenge-194/roger-bell-west/python/ch-2.py
@@ -0,0 +1,27 @@
+#! /usr/bin/python3
+
+import unittest
+from collections import defaultdict
+
+def frequencyequalizer(s):
+  f = defaultdict(lambda: 0)
+  for c in s:
+    f[c] += 1
+  v = list(f.values())
+  v.sort()
+  if v[0] == v[-2] and v[0] + 1 == v[-1]:
+    return True
+  return False
+
+class TestFrequencyEqualizer(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(frequencyequalizer("abbc"), True, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(frequencyequalizer("xyzyyxz"), True, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(frequencyequalizer("xzxz"), False, 'example 3')
+
+unittest.main()
diff --git a/challenge-194/roger-bell-west/raku/ch-1.p6 b/challenge-194/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..c5cf540c10
--- /dev/null
+++ b/challenge-194/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,32 @@
+#! /usr/bin/perl6
+
+use Test;
+
+plan 6;
+
+is(digitalclock("?5:00"), 1, 'example 1');
+is(digitalclock("?3:00"), 2, 'example 2');
+is(digitalclock("1?:00"), 9, 'example 3');
+is(digitalclock("2?:00"), 3, 'example 4');
+is(digitalclock("12:?5"), 5, 'example 5');
+is(digitalclock("12:5?"), 9, 'example 6');
+
+sub digitalclock($hhmm) {
+    my $i = index($hhmm, '?');
+    if ($i == 0) {
+        if (substr($hhmm, 1, 1) le "3") {
+            return 2;
+        }
+        return 1;
+    } elsif ($i == 1) {
+        if (substr($hhmm, 0, 1) lt "2") {
+            return 9;
+        }
+        return 3;
+    } elsif ($i == 3) {
+        return 5;
+    } elsif ($i == 4) {
+        return 9;
+    }
+    return 0;
+}
diff --git a/challenge-194/roger-bell-west/raku/ch-2.p6 b/challenge-194/roger-bell-west/raku/ch-2.p6
new file mode 100755
index 0000000000..2472656757
--- /dev/null
+++ b/challenge-194/roger-bell-west/raku/ch-2.p6
@@ -0,0 +1,22 @@
+#! /usr/bin/perl6
+
+use Test;
+
+plan 3;
+
+is(frequencyequalizer("abbc"), True, 'example 1');
+is(frequencyequalizer("xyzyyxz"), True, 'example 2');
+is(frequencyequalizer("xzxz"), False, 'example 3');
+
+sub frequencyequalizer($s) {
+  my %f;
+  for $s.comb -> $c {
+    %f{$c}++;
+  }
+  my @v = %f.values.sort;
+  if (@v[0] == @v[*-2] &&
+      @v[0] + 1 == @v[*-1]) {
+    return True;
+  }
+  return False;
+}
diff --git a/challenge-194/roger-bell-west/ruby/ch-1.rb b/challenge-194/roger-bell-west/ruby/ch-1.rb
new file mode 100755
index 0000000000..682ca2000f
--- /dev/null
+++ b/challenge-194/roger-bell-west/ruby/ch-1.rb
@@ -0,0 +1,51 @@
+#! /usr/bin/ruby
+
+require 'test/unit'
+
+def digitalclock(hhmm)
+  i = hhmm.index("?")
+  if i == 0 then
+    if hhmm[1] <= "3" then
+      return 2
+    end
+    return 1
+  elsif i == 1 then
+    if hhmm[0] < "2" then
+      return 9
+    end
+    return 3
+  elsif i == 3 then
+    return 5
+  elsif i == 4 then
+    return 9
+  end
+  return 0
+end
+
+class TestDigitalclock < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(1, digitalclock("?5:00"))
+  end
+
+  def test_ex2
+    assert_equal(2, digitalclock("?3:00"))
+  end
+
+  def test_ex3
+    assert_equal(9, digitalclock("1?:00"))
+  end
+
+  def test_ex4
+    assert_equal(3, digitalclock("2?:00"))
+  end
+
+  def test_ex5
+    assert_equal(5, digitalclock("12:?5"))
+  end
+
+  def test_ex6
+    assert_equal(9, digitalclock("12:5?"))
+  end
+
+end
diff --git a/challenge-194/roger-bell-west/ruby/ch-2.rb b/challenge-194/roger-bell-west/ruby/ch-2.rb
new file mode 100755
index 0000000000..f9fe41f6df
--- /dev/null
+++ b/challenge-194/roger-bell-west/ruby/ch-2.rb
@@ -0,0 +1,34 @@
+#! /usr/bin/ruby
+
+require 'test/unit'
+
+def frequencyequalizer(s)
+  f = Hash.new
+  s.chars.each do |c|
+    if !f.has_key?(c) then
+      f[c] = 0
+    end
+    f[c] += 1
+  end
+  v = f.values.sort
+  if v[0] == v[-2] &&
+     v[0] + 1 == v[-1] then
+    return true
+  end
+  return false
+end
+
+class TestFrequencyEqualizer < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(true, frequencyequalizer("abbc"))
+  end
+
+  def test_ex2
+    assert_equal(true, frequencyequalizer("xyzyyxz"))
+  end
+
+  def test_ex3
+    assert_equal(false, frequencyequalizer("xzxz"))
+  end
+end
diff --git a/challenge-194/roger-bell-west/rust/ch-1.rs b/challenge-194/roger-bell-west/rust/ch-1.rs
new file mode 100755
index 0000000000..056610aaf6
--- /dev/null
+++ b/challenge-194/roger-bell-west/rust/ch-1.rs
@@ -0,0 +1,53 @@
+#! /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!(digitalclock("?5:00"), 1);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(digitalclock("?3:00"), 2);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(digitalclock("1?:00"), 9);
+}
+
+#[test]
+fn test_ex4() {
+    assert_eq!(digitalclock("2?:00"), 3);
+}
+
+#[test]
+fn test_ex5() {
+    assert_eq!(digitalclock("12:?5"), 5);
+}
+
+#[test]
+fn test_ex6() {
+    assert_eq!(digitalclock("12:5?"), 9);
+}
+
+fn digitalclock(hhmm0: &str) -> u8 {
+    let i = hhmm0.find('?').unwrap();
+    let hhmm = hhmm0.chars().collect::<Vec<char>>();
+    if i == 0 {
+        if hhmm[1] <= '3' {
+            return 2;
+        }
+        return 1;
+    } else if i == 1 {
+        if hhmm[0] < '2' {
+            return 9;
+        }
+        return 3;
+    } else if i == 3 {
+        return 5;
+    } else if i == 4 {
+        return 9;
+    }
+    0
+}
diff --git a/challenge-194/roger-bell-west/rust/ch-2.rs b/challenge-194/roger-bell-west/rust/ch-2.rs
new file mode 100755
index 0000000000..70bd9c2362
--- /dev/null
+++ b/challenge-194/roger-bell-west/rust/ch-2.rs
@@ -0,0 +1,34 @@
+#! /bin/sh
+//usr/bin/env rustc --test $0 -o ${0}x && ./${0}x --nocapture; rm -f ${0}x ; exit
+
+use std::collections::HashMap;
+
+#[test]
+fn test_ex1() {
+    assert_eq!(frequencyequalizer("abbc"), true);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(frequencyequalizer("xyzyyxz"), true);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(frequencyequalizer("xzxz"), false);
+}
+
+fn frequencyequalizer(s: &str) -> bool {
+    let mut f: HashMap<char, usize> = HashMap::new();
+    for c in s.chars() {
+        let en = f.entry(c).or_insert(0);
+        *en += 1;
+    }
+    let mut v = f.into_values().collect::<Vec<usize>>();
+    v.sort();
+    if v[0] == v[v.len() - 2] && v[0] + 1 == v[v.len() - 1] {
+        true
+    } else {
+        false
+    }
+}