- Added solutions by Eric Cheung.

- Added solutions by Ulrich Rieke.
- Added solutions by Andrew Shitov.
- Added solutions by Feng Chang.
- Added solutions by Mark Anderson.
- Added solutions by E. Choroba.
- Added solutions by Simon Proctor.
- Added solutions by David Ferrone.
- Added solutions by Thomas Kohler.
- Added solutions by PokGoPun.
- Added solutions by Peter Campbell Smith.
- Added solutions by Dave Jacoby.
- Added solutions by Ali Moradi.
- Added solutions by Wanderdoc.
- Added solutions by Benjamin Andre.
- Added solutions by Yitzchak Scott-Thoennes.

37 files changed, 1063 insertions, 457 deletions

diff --git a/challenge-328/eric-cheung/python/ch-1.py b/challenge-328/eric-cheung/python/ch-1.py
new file mode 100755
index 0000000000..df35c89b20
--- /dev/null
+++ b/challenge-328/eric-cheung/python/ch-1.py
@@ -0,0 +1,26 @@
+

+## strInput = "a?z"  ## Example 1

+## strInput = "pe?k"  ## Example 2

+strInput = "gra?te"  ## Example 3

+

+arrOutput = []

+

+arrReplaceList = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"]

+

+for nIndx, charLoop in enumerate(strInput):

+    if charLoop != "?":

+        arrOutput.append(charLoop)

+        continue

+

+    ## print (nIndx, charLoop)

+

+    arrExclude = []

+    if nIndx > 0:

+        arrExclude.append(strInput[nIndx - 1])

+

+    if nIndx < len(strInput) - 1:

+        arrExclude.append(strInput[nIndx + 1])

+

+    arrOutput.append([charSubLoop for charSubLoop in arrReplaceList if not charSubLoop in arrExclude][0])

+

+print ("".join(arrOutput))

diff --git a/challenge-328/eric-cheung/python/ch-2.py b/challenge-328/eric-cheung/python/ch-2.py
new file mode 100755
index 0000000000..346602cc99
--- /dev/null
+++ b/challenge-328/eric-cheung/python/ch-2.py
@@ -0,0 +1,29 @@
+

+## strInput = "WeEeekly"  ## Example 1

+## strInput = "abBAdD"  ## Example 2

+strInput = "abc"  ## Example 3

+

+bProceed = True

+strTemp = strInput

+

+while bProceed:

+    bFound = False

+    arrTemp = list(strTemp)

+    for nIndx, charLoop in enumerate(arrTemp):

+        if nIndx == 0:

+            continue

+

+        if charLoop.lower() == arrTemp[nIndx - 1].lower() and charLoop != arrTemp[nIndx - 1]:

+            del arrTemp[nIndx]

+            del arrTemp[nIndx - 1]

+            bFound = True

+            break

+

+    strTemp = "".join(arrTemp)

+

+    if bFound:

+        continue

+

+    bProceed = False

+

+print (strTemp)

diff --git a/challenge-328/ulrich-rieke/cpp/ch-1.cpp b/challenge-328/ulrich-rieke/cpp/ch-1.cpp
new file mode 100755
index 0000000000..e89126afdb
--- /dev/null
+++ b/challenge-328/ulrich-rieke/cpp/ch-1.cpp
@@ -0,0 +1,26 @@
+#include <iostream>

+#include <string>

+#include <vector>

+#include <numeric>

+

+int main( ) {

+   std::cout << "Enter a word with lowercase English letters and one ?!\n" ;

+   std::string word ;

+   std::getline( std::cin , word ) ;

+   std::vector<char> characters( 26 ) ;

+   std::iota( characters.begin( ) , characters.end( ) , 'a' ) ;

+   auto found = word.find( '?' ) ;

+   char left_neighbour = word.substr( 0 , found  ).back( ) ;

+   char right_neighbour = word.substr( found + 1 ).front( ) ;

+   std::vector<char> remaining ;

+   for ( auto c : characters ) {

+      if (c != left_neighbour && c != right_neighbour ) {

+	 remaining.push_back( c ) ;

+      }

+   }

+   std::string changed { word.substr( 0 , found  ) } ;

+   changed.push_back( remaining[0] ) ;

+   changed.append( word.substr( found + 1 ) ) ;

+   std::cout << changed << '\n' ;

+   return 0 ;

+}

diff --git a/challenge-328/ulrich-rieke/cpp/ch-2.cpp b/challenge-328/ulrich-rieke/cpp/ch-2.cpp
new file mode 100755
index 0000000000..37f52fc15c
--- /dev/null
+++ b/challenge-328/ulrich-rieke/cpp/ch-2.cpp
@@ -0,0 +1,33 @@
+#include <iostream>

+#include <string>

+#include <cstdlib>

+

+int main( ) {

+   std::cout << "Enter a word with English letters only!\n" ;

+   std::string word ;

+   std::getline( std::cin , word ) ;

+   std::string solution ;

+   int len = static_cast<int>(word.length( ) ) ;

+   int pos = 0 ;

+   while ( pos < len ) {

+      solution.push_back( word[pos] ) ;

+      int l = static_cast<int>(solution.length( ) ) ;

+      if ( l > 1 ) {

+	 char first = solution[l - 2] ;

+	 char second = solution[l - 1] ;

+	 if ( std::abs( static_cast<int>( first ) - static_cast<int>(second ) )

+	       == 32 ) {

+	    solution = solution.substr( 0 , l - 2 ) ;

+	 }

+      }

+      pos++ ;

+   }

+   if ( solution.length( ) > 0 ) {

+      std::cout << solution ;

+   }

+   else {

+      std::cout << "\"\"" ;

+   }

+   std::cout << '\n' ;

+   return 0 ;

+}

diff --git a/challenge-328/ulrich-rieke/haskell/ch-1.hs b/challenge-328/ulrich-rieke/haskell/ch-1.hs
new file mode 100755
index 0000000000..16cf15368a
--- /dev/null
+++ b/challenge-328/ulrich-rieke/haskell/ch-1.hs
@@ -0,0 +1,18 @@
+module Challenge328

+   where

+import Data.List ( findIndices , (\\) , (!!) ) 

+

+change :: String -> String   

+change str = 

+   let position = head $ findIndices (== '?' ) str

+       left = if position > 0 then position - 1 else 0

+       l    = length str

+       right = if position < l - 1 then position + 1 else l - 1

+       remaining = ['a'..'z'] \\ [str !! left , str !! right]

+   in take position str ++ [head remaining] ++ drop ( position + 1 ) str

+

+main :: IO ( )

+main = do

+   putStrLn "Enter a string with lowercase English letters and one ?!" 

+   wordline <- getLine

+   print $ change wordline

diff --git a/challenge-328/ulrich-rieke/haskell/ch-2.hs b/challenge-328/ulrich-rieke/haskell/ch-2.hs
new file mode 100755
index 0000000000..0b102d9641
--- /dev/null
+++ b/challenge-328/ulrich-rieke/haskell/ch-2.hs
@@ -0,0 +1,30 @@
+module Challenge328_2

+   where

+import Data.List.Split( divvy )

+import Data.List ( findIndex , (!!)) 

+import Data.Char ( ord ) 

+import Data.Maybe ( isJust , fromJust ) 

+

+condition :: [(Int , Char)] -> Bool

+condition sublist = abs ( (ord $ snd $ head sublist) - ( ord $ snd $ last

+ sublist )) == 32

+

+changeStr :: String -> String

+changeStr str = 

+   let zipped = zip [0 , 1 .. ] str

+       paired = divvy 2 1 zipped

+       result = findIndex condition paired

+   in if isJust result then take (fst $ head $ paired !! (fromJust result)) str ++

+   ( drop ((fst $ last $ paired !! (fromJust result) ) + 1 ) str ) else str

+	 

+solution :: String -> String

+solution str = fst $ until snd step ( str , False )

+   where

+    step :: (String , Bool) -> (String , Bool)

+    step ( aString , changed ) = ( changeStr aString , changeStr aString == aString) 

+

+main :: IO ( )

+main = do

+   putStrLn "Enter a word with English letters only!"

+   aWord <- getLine

+   print $ solution aWord

diff --git a/challenge-328/ulrich-rieke/perl/ch-1.pl b/challenge-328/ulrich-rieke/perl/ch-1.pl
new file mode 100755
index 0000000000..85736e36c7
--- /dev/null
+++ b/challenge-328/ulrich-rieke/perl/ch-1.pl
@@ -0,0 +1,18 @@
+#!/usr/bin/perl ;

+use strict ;

+use warnings ;

+use feature 'say' ;

+

+say "Enter a word with lower case English characters and one ?!" ;

+my $word = <STDIN> ;

+chomp $word ;

+my @characters = ('a'..'z') ;

+my %found ;

+if ( $word =~ /(.)\?(.)/ ) {

+   $found{$1}++ ;

+   $found{$2}++ ;

+}

+my @difference = grep { not exists( $found{$_} ) } @characters ;

+my $replacement = $difference[0] ;

+$word =~ s/\?/$replacement/ ;

+say $word ;

diff --git a/challenge-328/ulrich-rieke/perl/ch-2.pl b/challenge-328/ulrich-rieke/perl/ch-2.pl
new file mode 100755
index 0000000000..23e6577f9f
--- /dev/null
+++ b/challenge-328/ulrich-rieke/perl/ch-2.pl
@@ -0,0 +1,29 @@
+#!/usr/bin/perl ;

+use strict ;

+use warnings ;

+use feature 'say' ;

+

+say "Enter a string with English letters!" ;

+my $word = <STDIN> ;

+chomp $word ;

+my $solution ;

+my $len = length( $word ) ;

+my $pos = 0 ;

+while ( $pos < $len ) {

+   $solution .= substr( $word , $pos , 1 ) ;

+   my $l = length( $solution ) ;

+   if ( $l > 1 ) {

+      my $first = substr( $solution , $l - 2  , 1 ) ;

+      my $second = substr( $solution , $l - 1 , 1 ) ;

+      if ( abs( ord( $first ) - ord( $second ) ) == 32 ) {

+	 $solution = substr( $solution , 0 , $l - 2 ) ;

+      }

+   }

+   $pos++ ;

+}

+if ( $solution ) {

+   say $solution ;

+}

+else {

+   say "\"\"" ;

+}

diff --git a/challenge-328/ulrich-rieke/raku/ch-1.raku b/challenge-328/ulrich-rieke/raku/ch-1.raku
new file mode 100755
index 0000000000..ac5f7a04e5
--- /dev/null
+++ b/challenge-328/ulrich-rieke/raku/ch-1.raku
@@ -0,0 +1,11 @@
+use v6 ;

+

+say "Enter a word!" ;

+my $word = $*IN.get ;

+my $characters = ('a'..'z').Set ;

+if ( $word ~~ /(.) '?' (.)/ ) {

+   my $remaining = $characters (-) (~$0 , ~$1).Set ;

+   my $replacement = $remaining.keys[0] ;

+   $word ~~ s/'?'/$replacement/ ;

+}

+say $word ;

diff --git a/challenge-328/ulrich-rieke/raku/ch-2.raku b/challenge-328/ulrich-rieke/raku/ch-2.raku
new file mode 100755
index 0000000000..05cb658c75
--- /dev/null
+++ b/challenge-328/ulrich-rieke/raku/ch-2.raku
@@ -0,0 +1,25 @@
+use v6 ;

+

+say "Enter a word with English letters only!" ;

+my $word = $*IN.get ;

+my $solution ;

+my $len = $word.chars ;

+my $pos = 0 ;

+while ( $pos < $len ) {

+   $solution ~= $word.substr( $pos , 1 ) ;

+   my $l = $solution.chars ;

+   if ( $l > 1 ) {

+      my $first = $solution.substr( $l - 2 , 1 ) ;

+      my $second = $solution.substr( $l - 1 , 1 ) ;

+      if (( $first.ord - $second.ord).abs == 32 ) {

+	 $solution = $solution.substr( 0 , $l - 2 ) ;

+      }

+   }

+   $pos++ ;

+}

+if ( $solution ) {

+   say $solution ;

+}

+else {

+   say "\"\"" ;

+}

diff --git a/challenge-328/ulrich-rieke/rust/ch-1.rs b/challenge-328/ulrich-rieke/rust/ch-1.rs
new file mode 100755
index 0000000000..703cd2b785
--- /dev/null
+++ b/challenge-328/ulrich-rieke/rust/ch-1.rs
@@ -0,0 +1,39 @@
+use std::io ;
+use std::collections::HashSet ;
+
+fn main() {
+    println!("Enter a string with lowercase English letters and one ?!");
+    let mut inline : String = String::new( ) ;
+    io::stdin( ).read_line( &mut inline ).unwrap( ) ;
+    let trimmed = inline.trim( ) ; 
+    let mut characters : HashSet<char> = HashSet::new( ) ;
+    for c in 'a'..='z' {
+       characters.insert( c ) ;
+    }
+    let len : usize = trimmed.chars( ).count( ) ;
+    let mut after : String = String::new( ) ;
+    if let Some( pos ) = trimmed.find( '?' ) {
+       let mut left_neighbour : char = ' ' ;
+       let mut right_neighbour : char = ' ' ;
+       if pos > 0 {
+	  left_neighbour = trimmed.chars( ).nth(pos - 1).unwrap( ) ;
+       }
+       if pos < len - 1 {
+	  right_neighbour = trimmed.chars( ).nth( pos + 1 ).unwrap( ) ;
+       }
+       let mut already_there : HashSet<char> = HashSet::new( ) ;
+       already_there.insert( left_neighbour ) ;
+       already_there.insert( right_neighbour ) ;
+       let diff : HashSet<&char> = characters.difference( &already_there ).collect( ) ;
+       if diff.len( ) > 0 {
+	  let mut repl : String = String::new( ) ;
+	  for x in diff.iter( ) {
+              repl.push(**x) ;
+	      break ;
+	  }
+	  let replacement = repl.as_str( ) ;
+	  after = trimmed.replace( "?" , replacement ) ;
+       }
+    }
+    println!("{:?}" , after ) ;
+}
diff --git a/challenge-328/ulrich-rieke/rust/ch-2.rs b/challenge-328/ulrich-rieke/rust/ch-2.rs
new file mode 100755
index 0000000000..350bcdf5fe
--- /dev/null
+++ b/challenge-328/ulrich-rieke/rust/ch-2.rs
@@ -0,0 +1,31 @@
+use std::io ;
+
+fn main() {
+    println!("Enter a string with English letters only!");
+    let mut inline : String = String::new( ) ;
+    io::stdin( ).read_line( &mut inline ).unwrap( ) ;
+    let mut entered : &str = inline.trim( ) ;
+    let mut trimmed : String = entered.into( ) ;
+    let mut len : usize = entered.chars( ).count( ) ;
+    let mut pos : usize = 0 ;
+    while pos < len - 1 {
+       let first_char : char = entered.chars( ).nth( pos ).unwrap( ) ;
+       let second_char : char = entered.chars( ).nth( pos + 1 ).unwrap( ) ;
+       if (first_char.to_ascii_lowercase( ) == second_char || 
+	  first_char.to_ascii_uppercase( ) == second_char ) && 
+          first_char != second_char {
+	     trimmed.remove( pos ) ;
+	     trimmed.remove( pos ) ;
+	     entered = trimmed.as_str( ) ;
+	     len = entered.chars( ).count( ) ;
+	     if len == 0 {
+		break ;
+	     }
+	     pos = 0 ;
+       }
+       else {
+	  pos += 1 ;
+       }
+    }
+    println!("{:?}" , trimmed ) ;
+}
diff --git a/guests.json b/guests.json
index cfcdf884fa..f27a00660d 100644
--- a/guests.json
+++ b/guests.json
@@ -4,6 +4,7 @@
     "archargelod"     : "Archar Gelod",
     "ashwin-shenoy"   : "Ashwin Shenoy",
     "aviral-goel"     : "Aviral Goel",
+    "benjamin-andre"  : "Benjamin Andre",
     "chazzka"         : "Chazzka",
     "conor-hoekstra"  : "Conor Hoekstra",
     "daniel-aberger"  : "Daniel Aberger",
diff --git a/stats/pwc-challenge-327.json b/stats/pwc-challenge-327.json
new file mode 100644
index 0000000000..bf9b729696
--- /dev/null
+++ b/stats/pwc-challenge-327.json
@@ -0,0 +1,607 @@
+{
+   "chart" : {
+      "type" : "column"
+   },
+   "drilldown" : {
+      "series" : [
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Blog",
+                  2
+               ]
+            ],
+            "id" : "Adam Russell",
+            "name" : "Adam Russell"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "Ali Moradi",
+            "name" : "Ali Moradi"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Andreas Mahnke",
+            "name" : "Andreas Mahnke"
+         },
+         {
+            "data" : [
+               [
+                  "Raku",
+                  2
+               ]
+            ],
+            "id" : "Andrew Shitov",
+            "name" : "Andrew Shitov"
+         },
+         {
+            "data" : [
+               [
+                  "Raku",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "Arne Sommer",
+            "name" : "Arne Sommer"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Raku",
+                  2
+               ]
+            ],
+            "id" : "Athanasius",
+            "name" : "Athanasius"
+         },
+         {
+            "data" : [
+               [
+                  "Raku",
+                  2
+               ]
+            ],
+            "id" : "BarrOff",
+            "name" : "BarrOff"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Bob Lied",
+            "name" : "Bob Lied"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "David Ferrone",
+            "name" : "David Ferrone"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "E. Choroba",
+            "name" : "E. Choroba"
+         },
+         {
+            "data" : [
+               [
+                  "Raku",
+                  2
+               ]
+            ],
+            "id" : "Feng Chang",
+            "name" : "Feng Chang"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Raku",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "Jaldhar H. Vyas",
+            "name" : "Jaldhar H. Vyas"
+         },
+         {
+            "data" : [
+               [
+                  "Raku",
+                  2
+               ]
+            ],
+            "id" : "Jan Krnavek",
+            "name" : "Jan Krnavek"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "Jorg Sommrey",
+            "name" : "Jorg Sommrey"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Kjetil Skotheim",
+            "name" : "Kjetil Skotheim"
+         },
+         {
+            "data" : [
+               [
+                  "Raku",
+                  2
+               ]
+            ],
+            "id" : "Mark Anderson",
+            "name" : "Mark Anderson"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "Matthias Muth",
+            "name" : "Matthias Muth"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Niels van Dijke",
+            "name" : "Niels van Dijke"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Raku",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "Packy Anderson",
+            "name" : "Packy Anderson"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "Peter Campbell Smith",
+            "name" : "Peter Campbell Smith"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Peter Meszaros",
+            "name" : "Peter Meszaros"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "Robbie Hatley",
+            "name" : "Robbie Hatley"
+         },
+         {
+            "data" : [
+               [
+                  "Raku",
+                  2
+               ]
+            ],
+            "id" : "Robert Ransbottom",
+            "name" : "Robert Ransbottom"
+         },
+         {
+            "data" : [
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "Roger Bell_West",
+            "name" : "Roger Bell_West"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Simon Green",
+            "name" : "Simon Green"
+         },
+         {
+            "data" : [
+               [
+                  "Raku",
+                  2
+               ]
+            ],
+            "id" : "Simon Proctor",
+            "name" : "Simon Proctor"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Blog",
+                  2
+               ]
+            ],
+            "id" : "Thomas Kohler",
+            "name" : "Thomas Kohler"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Ulrich Reining",
+            "name" : "Ulrich Reining"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Raku",
+                  2
+               ]
+            ],
+            "id" : "Ulrich Rieke",
+            "name" : "Ulrich Rieke"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ],
+            "id" : "W. Luis Mochan",
+            "name" : "W. Luis Mochan"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Walt Mankowski",
+            "name" : "Walt Mankowski"
+         },
+         {
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Wanderdoc",
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