- Added solutions by Matthias Muth.

- Added solutions by Simon Proctor.
- Added solutions by Laurent Rosenfeld.
- Added solutions by Robert DiCicco.
- Added solutions by Ulrich Rieke.
- Added solutions by Thomas Kohler.
- Added solutions by Mark Anderson.
- Added solutions by E. Choroba.
- Added solutions by David Ferrone.
- Added solutions by W. Luis Mochan.
- Added solutions by Bob Lied.
- Added solutions by Peter Campbell Smith.
- Added solutions by Ali Muradi.
- Added solutions by Robbie Hatley.
- Added solutions by Jorg Sommrey.
- Added solutions by Lubos Kolouch.
- Added solutions by Niels van Dijke.
- Added solutions by Roger Bell_West.
- Added solutions by Arne Sommer.
- Added solutions by Robert Ransbottom.
- Added solutions by Andreas Vogele.

45 files changed, 3914 insertions, 2543 deletions

diff --git a/challenge-221/blog.txt b/challenge-221/bob-lied/blog.txt
index 5b69803d6a..5b69803d6a 100644
--- a/challenge-221/blog.txt
+++ b/challenge-221/bob-lied/blog.txt
diff --git a/challenge-221/perl/ch-1.pl b/challenge-221/bob-lied/perl/ch-1.pl
index 1978b64c5a..1978b64c5a 100755
--- a/challenge-221/perl/ch-1.pl
+++ b/challenge-221/bob-lied/perl/ch-1.pl
diff --git a/challenge-221/perl/ch-2.pl b/challenge-221/bob-lied/perl/ch-2.pl
index f9de84d188..f9de84d188 100755
--- a/challenge-221/perl/ch-2.pl
+++ b/challenge-221/bob-lied/perl/ch-2.pl
diff --git a/challenge-221/eric-cheung/python/ch-1.py b/challenge-221/eric-cheung/python/ch-1.py
new file mode 100755
index 0000000000..5e47922272
--- /dev/null
+++ b/challenge-221/eric-cheung/python/ch-1.py
@@ -0,0 +1,38 @@
+

+## Example 1

+## arrInputWords = ["cat", "bt", "hat", "tree"]

+## strChars = "atach"

+

+## Example 2

+arrInputWords = ["hello", "world", "challenge"]

+strChars = "welldonehopper"

+

+arrUniqChar = list(set(strChars))

+arrUniqCharCount = [strChars.count(charLoop) for charLoop in arrUniqChar]

+

+arrOutputWords = []

+nSumCharLength = 0

+

+for strLoop in arrInputWords:

+    arrCharCount = arrUniqCharCount[:]

+    bIsFound = True

+

+    for charLoop in strLoop:

+        if not charLoop in arrUniqChar:

+            bIsFound = False

+            break

+

+        nIndx = arrUniqChar.index(charLoop)

+

+        if arrCharCount[nIndx] == 0:

+            bIsFound = False

+            break

+

+        arrCharCount[nIndx] = arrCharCount[nIndx] - 1

+

+    if bIsFound:

+        arrOutputWords.append(strLoop)

+        nSumCharLength = nSumCharLength + len(strLoop)

+

+## print (arrOutputWords)

+print (nSumCharLength)

diff --git a/challenge-221/eric-cheung/python/ch-2.py b/challenge-221/eric-cheung/python/ch-2.py
new file mode 100755
index 0000000000..0288a402e5
--- /dev/null
+++ b/challenge-221/eric-cheung/python/ch-2.py
@@ -0,0 +1,47 @@
+

+## Remarks

+## https://www.geeksforgeeks.org/generating-all-possible-subsequences-using-recursion/

+

+## Python3 code to print all possible subsequences for given array using recursion

+## Recursive function to print all possible subsequences for given array

+

+nMaxArrLen = 0

+

+def IsArithmetic (arrListCheck):

+

+    nDiff = arrListCheck[1] - arrListCheck[0]

+    for nIndxLoop in range(2, len(arrListCheck)):

+        if arrListCheck[nIndxLoop] - arrListCheck[nIndxLoop - 1] != nDiff:

+            return False

+

+    return True

+

+def GenSubseqArr (arrFunc, nIndx, subArrFunc):

+

+    global nMaxArrLen

+

+    ## Print the subsequence when reach the leaf of recursion tree

+    if nIndx == len(arrFunc):

+        ## Condition to avoid printing empty subsequence

+        ## if len(subArrFunc) > 0:

+        if len(subArrFunc) > 2 and IsArithmetic(subArrFunc):

+            ## print (subArrFunc)

+            if len(subArrFunc) > nMaxArrLen:

+                nMaxArrLen = len(subArrFunc)

+

+    else:

+        ## Subsequence without including the element at current nIndx

+        GenSubseqArr(arrFunc, nIndx + 1, subArrFunc)

+

+        ## Subsequence including the element at current nIndx

+        GenSubseqArr(arrFunc, nIndx + 1, subArrFunc + [arrFunc[nIndx]])

+

+    return

+

+arrGivenMain = [9, 4, 7, 2, 10]  ## Example 1

+## arrGivenMain = [3, 6, 9, 12]  ## Example 2

+## arrGivenMain = [20, 1, 15, 3, 10, 5, 8]  ## Example 3

+

+GenSubseqArr(arrGivenMain, 0, [])

+

+print (nMaxArrLen)

diff --git a/challenge-221/laurent-rosenfeld/blog.txt b/challenge-221/laurent-rosenfeld/blog.txt
new file mode 100644
index 0000000000..76372000c8
--- /dev/null
+++ b/challenge-221/laurent-rosenfeld/blog.txt
@@ -0,0 +1 @@
+https://blogs.perl.org/users/laurent_r/2023/06/perl-weekly-challenge-221-good-strings.html
diff --git a/challenge-221/laurent-rosenfeld/blog1.txt b/challenge-221/laurent-rosenfeld/blog1.txt
new file mode 100644
index 0000000000..d1008ecc08
--- /dev/null
+++ b/challenge-221/laurent-rosenfeld/blog1.txt
@@ -0,0 +1 @@
+https://blogs.perl.org/users/laurent_r/2023/06/perl-weekly-challenge-221-arithmetic-subsequence.html
diff --git a/challenge-221/laurent-rosenfeld/perl/ch-1.pl b/challenge-221/laurent-rosenfeld/perl/ch-1.pl
new file mode 100644
index 0000000000..dee5b9c37f
--- /dev/null
+++ b/challenge-221/laurent-rosenfeld/perl/ch-1.pl
@@ -0,0 +1,28 @@
+use strict;
+use warnings;
+use feature 'say';
+
+sub find_good {
+    my ($string, @words) = @_;
+    # say $string, " - ", "@words";
+    my $length = 0;
+    my %chars;
+    $chars{$_}++ for split //, $string;
+    WORD: for my $word (@words) {
+        my %char_cpy = %chars;
+        for my $let (split //, $word) {
+            next WORD unless $char_cpy{$let};
+            $char_cpy{$let}--;
+        }
+        $length += length $word;
+    }
+    return $length
+}
+for my $test (
+    ["atach", [<cat bt hat tree>]],
+    ["atach", [<cat bt hat tree cata>]],
+    ["atach", [<cat bt hat tree ataca>]],
+    ["welldonehopper", [<hello world challenge>]]) {
+    printf "%-15s - %-22s => ", "@$test[0]", "@{@$test[1]}";
+    say find_good  @$test[0], @{@$test[1]};
+}
diff --git a/challenge-221/laurent-rosenfeld/perl/ch-2.pl b/challenge-221/laurent-rosenfeld/perl/ch-2.pl
new file mode 100644
index 0000000000..a577abbfbc
--- /dev/null
+++ b/challenge-221/laurent-rosenfeld/perl/ch-2.pl
@@ -0,0 +1,25 @@
+use strict;
+use warnings;
+use feature 'say';
+
+sub longest_subseq {
+    my @pairs;
+    for my $i (0..$#_) {
+        for my $j ($i+1..$#_) {
+            push @pairs, [$_[$i], $_[$j]];
+        }
+    }
+    my %gaps;
+    $gaps{($_->[1] - $_->[0])}++ for @pairs;
+    my $max = 0;
+    for my $k (keys %gaps) {
+        $max = $gaps{$k} if $gaps{$k} > $max;
+    }
+    # For n gaps, we have n + 1 values
+    return $max + 1;
+}
+
+for my $test ( [<9 4 7 2 10>], [<3 6 9 12>], [<20 1 15 3 10 5 8>] ) {
+    printf "%-18s => ", "@$test";
+    say longest_subseq @$test;
+}
diff --git a/challenge-221/laurent-rosenfeld/raku/ch-1.raku b/challenge-221/laurent-rosenfeld/raku/ch-1.raku
new file mode 100644
index 0000000000..b7d322e00d
--- /dev/null
+++ b/challenge-221/laurent-rosenfeld/raku/ch-1.raku
@@ -0,0 +1,14 @@
+sub find-good ($string, @words) {
+    my $chars = $string.comb.Bag;
+    my $length = 0;
+    for @words -> $word {
+        $length += $word.chars if $word.comb.Bag ⊆ $chars;
+    }
+    return $length
+}
+for (("atach", <cat bt hat tree atac>),
+    ("atach", <cat bt hat tree ataca>),
+    ("welldonehopper", <hello world challenge>)) -> @test {
+    printf "%-15s - %-22s => ", "@test[0]", "@test[1]";
+    say find-good  @test[0], @test[1];
+}
diff --git a/challenge-221/laurent-rosenfeld/raku/ch-2.raku b/challenge-221/laurent-rosenfeld/raku/ch-2.raku
new file mode 100644
index 0000000000..9e11e6f79e
--- /dev/null
+++ b/challenge-221/laurent-rosenfeld/raku/ch-2.raku
@@ -0,0 +1,11 @@
+sub longest-subseq (@in) {
+    my @pairs = @in.combinations: 2;
+    my %gaps;
+    %gaps{~($_[1] - $_[0])}++ for @pairs;
+    # For n gaps, we have n + 1 values
+    return %gaps.values.max + 1;
+}
+
+for <9 4 7 2 10>, <3 6 9 12>, <20 1 15 3 10 5 8> -> @test {
+    printf "%-18s => %d\n", ~(@test), longest-subseq @test;
+}
diff --git a/challenge-221/perlboy1967/perl/ch1.pl b/challenge-221/perlboy1967/perl/ch-1.pl
index a84549d1d4..a84549d1d4 100755
--- a/challenge-221/perlboy1967/perl/ch1.pl
+++ b/challenge-221/perlboy1967/perl/ch-1.pl
diff --git a/challenge-221/robert-dicicco/julia/ch-1.jl b/challenge-221/robert-dicicco/julia/ch-1.jl
new file mode 100644
index 0000000000..0d75c4eebe
--- /dev/null
+++ b/challenge-221/robert-dicicco/julia/ch-1.jl
@@ -0,0 +1,63 @@
+#!/usr/bin/env julia
+#=
+-------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-13
+Challenge 221 Task 1 Good Strings ( Julia )
+-------------------------------------
+=#
+
+using Printf
+
+total_score = 0
+
+words = [["cat", "bt", "hat", "tree"], ["hello", "world", "challenge"]]
+chlist = ["atach","welldonehopper"]
+cnt = 1
+listcnt = 1
+
+for wds in words
+    @printf("Input: @words = %s\n",wds)
+    chars = chlist[cnt]
+    global total_score = 0
+    score = 0
+    for w in wds
+        ln = length(w)
+        for mycnt in 1:ln
+            tst = w[mycnt]
+            if occursin(tst, chlist[listcnt])
+                score += 1
+            else
+                break
+            end
+        end
+        if score == ln
+            @printf("%s\n",w)
+            total_score += score
+            score = 0
+        end
+    end
+    @printf("\tTotal: %d\n", total_score)
+    println()
+    global listcnt += 1
+end
+
+#=
+-------------------------------------
+SAMPLE OUTPUT
+julia .\GoodStrings.jl
+
+Input: @words = ["cat", "bt", "hat", "tree"]
+cat
+hat
+        Total: 6
+
+Input: @words = ["hello", "world", "challenge"]
+hello
+world
+        Total: 10
+-------------------------------------
+=#
+
+
+
diff --git a/challenge-221/robert-dicicco/perl/ch-1.pl b/challenge-221/robert-dicicco/perl/ch-1.pl
new file mode 100644
index 0000000000..012a057a2f
--- /dev/null
+++ b/challenge-221/robert-dicicco/perl/ch-1.pl
@@ -0,0 +1,60 @@
+#!/usr/bin/env perl
+=begin comment
+-------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-12
+Challenge 221 Task 1 Good Strings ( Perl )
+-------------------------------------
+=cut
+use strict;
+use warnings;
+use feature 'say';
+
+my $total_score = 0;
+
+my @words = (["cat", "bt", "hat", "tree"], ["hello", "world", "challenge"]);
+my @chlist = ("atach","welldonehopper");
+my $cnt = 0;
+for my $word (@words) {
+    say "Input: \@words = (@$word)";
+    my $chars = $chlist[$cnt];
+    $total_score = 0;
+    for my $w (@$word) {
+        my $ln = length($w);
+        my $score = 0;
+        for (my $cnt = 0; $cnt < $ln; $cnt++){
+            my $tst = substr($w,$cnt,1);
+            if ($chars =~ /$tst/) {
+                 $score++;
+            } else {
+                 last;
+            }
+
+        }
+        if ($score == $ln) {
+            say $w;
+            $total_score += $score;
+            $score = 0;
+        }
+     }
+     say "\tTotal: ", $total_score;
+     say "";
+     $cnt++;
+}
+
+=begin comment
+-------------------------------------
+SAMPLE OUTPUT
+perl .\GoodStrings.pl
+
+Input: @words = (cat bt hat tree)
+cat
+hat
+        Total: 6
+
+Input: @words = (hello world challenge)
+hello
+world
+        Total: 10
+-------------------------------------
+=cut
diff --git a/challenge-221/robert-dicicco/python/ch-1.py b/challenge-221/robert-dicicco/python/ch-1.py
new file mode 100644
index 0000000000..5433676bd3
--- /dev/null
+++ b/challenge-221/robert-dicicco/python/ch-1.py
@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+# -------------------------------------
+# AUTHOR: Robert DiCicco
+# DATE  : 2023-06-13
+# Challenge 221 Task 1 Good Strings ( Python )
+# -------------------------------------
+
+total_score = 0
+
+words = [["cat", "bt", "hat", "tree"], ["hello", "world", "challenge"]]
+chlist = ["atach","welldonehopper"]
+cnt = 0
+listcnt = 0
+
+for wds in words:
+    print("Input: @words = ",wds)
+    chars = chlist[cnt]
+    total_score = 0
+    score = 0
+    for w in wds:
+        ln = len(w)
+        for mycnt in range(0,ln):
+            tst = w[mycnt]
+            if tst in chlist[listcnt]:
+                score += 1
+            else:
+                break
+        if score == ln:
+            print(w)
+            total_score += score
+            score = 0
+    print("\tTotal: ",total_score)
+    print("")
+    listcnt += 1
+
+# -------------------------------------
+# SAMPLE OUTPUT
+# python .\GoodStrings.py
+
+# Input: @words =  ['cat', 'bt', 'hat', 'tree']
+# cat
+# hat
+        # Total:  6
+
+# Input: @words =  ['hello', 'world', 'challenge']
+# hello
+# world
+        # Total:  10
+# -------------------------------------
+
+
diff --git a/challenge-221/robert-dicicco/raku/ch-1.raku b/challenge-221/robert-dicicco/raku/ch-1.raku
new file mode 100644
index 0000000000..2216add23d
--- /dev/null
+++ b/challenge-221/robert-dicicco/raku/ch-1.raku
@@ -0,0 +1,58 @@
+#!/usr/bin/env raku
+=begin comment
+-------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-12
+Challenge 221 Task 1 Good Strings ( Raku )
+-------------------------------------
+=end comment
+
+my $total_score = 0;
+
+my @words = (["cat", "bt", "hat", "tree"], ["hello", "world", "challenge"]);
+my @chlist = ("atach","welldonehopper");
+my $cnt = 0;
+for (@words) -> @word {
+    say "Input: \@words = ",@word;
+    my $chars = @chlist[$cnt];
+    $total_score = 0;
+    for (@word) -> $w {
+        my $ln = $w.chars;
+        my $score = 0;
+        loop (my $cnt = 0; $cnt < $ln; $cnt++){
+            my $tst = substr($w,$cnt,1);
+            if $chars.contains($tst) {
+                $score++;
+            } else {
+                last;
+            }
+        }
+        if ($score == $ln) {
+            say $w;
+            $total_score += $score;
+            $score = 0;
+        }
+    }
+    say "\tTotal: ", $total_score;
+     say "";
+     $cnt++;
+}
+
+=begin comment
+-------------------------------------
+SAMPLE OUTPUT
+raku .\GoodStrings.rk
+
+Input: @words = [cat bt hat tree]
+cat
+hat
+        Total: 6
+
+Input: @words = [hello world challenge]
+hello
+world
+        Total: 10
+-------------------------------------
+=end comment
+
+
diff --git a/challenge-221/robert-dicicco/ruby/ch-1.rb b/challenge-221/robert-dicicco/ruby/ch-1.rb
new file mode 100644
index 0000000000..2bb6caae75
--- /dev/null
+++ b/challenge-221/robert-dicicco/ruby/ch-1.rb
@@ -0,0 +1,62 @@
+#!/usr/bin/env ruby
+=begin
+-------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-12
+Challenge 221 Task 1 Good Strings ( Ruby )
+-------------------------------------
+=end
+
+total_score = 0
+
+words = [["cat", "bt", "hat", "tree"], ["hello", "world", "challenge"]]
+chlist = ["atach","welldonehopper"]
+cnt = 0
+listcnt = 0
+
+words.each do |wds|
+    puts("Input: @words = #{wds}")
+    chars = chlist[cnt]
+    total_score = 0
+    wds.each do |w|
+        ln = w.length
+        score = 0
+        for cnt in 0..ln-1 do
+            tst = w[cnt,1]
+            if chlist[listcnt].include? tst
+                 score += 1
+            else
+                break
+            end
+        end
+        if score == ln
+            puts("#{w}")
+            total_score += score
+            score = 0
+         end
+    end
+    puts("\tTotal: #{total_score}\n\n")
+    cnt += 1
+    listcnt += 1
+end
+
+=begin
+-------------------------------------
+SAMPLE OUTPUT
+ruby .\GoodStrings.rb
+Input: @words = ["cat", "bt", "hat", "tree"]
+cat
+hat
+        Total: 6
+
+Input: @words = ["hello", "world", "challenge"]
+hello
+world
+        Total: 10
+-------------------------------------
+=end
+
+
+
+
+
diff --git a/challenge-221/ulrich-rieke/cpp/ch-1.cpp b/challenge-221/ulrich-rieke/cpp/ch-1.cpp
new file mode 100644
index 0000000000..71caaed73c
--- /dev/null
+++ b/challenge-221/ulrich-rieke/cpp/ch-1.cpp
@@ -0,0 +1,64 @@
+#include <iostream>
+#include <string>
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <numeric>
+
+std::vector<std::string> split( const std::string & startline ,
+      const std::string & sep ) {
+  std::vector<std::string> separated ;
+  std::string::size_type start { 0 } ;
+  std::string::size_type pos ;
+  do {
+      pos = startline.find_first_of( sep , start ) ;
+      separated.push_back( startline.substr(start , pos - start )) ;
+      start = pos + 1 ;
+  } while ( pos != std::string::npos ) ;
+  return separated ;
+}
+
+bool condition( const std::string & word , const std::map<char, int> &
+      provided ) {
+  std::map<char , int> lettercount ;
+  for ( char c : word )
+      lettercount[c]++ ;
+  for ( char c : word ) {
+      if ( ! ( provided.find( c ) != provided.end( ) &&
+          (provided.find( c ))->second >=
+          (lettercount.find( c ) )->second ) )
+        return false ;
+  }
+  return true ;
+}
+
+
+int main( ) {
+  std::cout << "Enter some words, separated by blanks!\n" ;
+  std::string line ;
+  std::getline( std::cin , line ) ;
+  std::vector<std::string> words ( split( line, " " ) ) ;
+  std::cout << "Enter a word to take the characters from!\n" ;
+  std::string comparator ;
+  std::cin >> comparator ;
+  std::map<char , int> compCount ;
+  for ( char c : comparator )
+      compCount[c]++ ;
+  std::vector<std::string> selected ;
+  for ( auto s : words ) {
+      if ( condition( s , compCount ) ) {
+    selected.push_back( s ) ;
+      }
+  }
+  if ( selected.size( ) > 0 ) {
+      std::vector<int> lengths  ;
+      for ( auto s : selected )
+    lengths.push_back( s.length( ) ) ;
+      std::cout << std::accumulate( lengths.begin( ) , lengths.end( ) , 0 )
+    << std::endl ;
+  }
+  else {
+      std::cout << 0 << std::endl ;
+  }
+  return 0 ;
+}
diff --git a/challenge-221/ulrich-rieke/cpp/ch-2.cpp b/challenge-221/ulrich-rieke/cpp/ch-2.cpp
new file mode 100644
index 0000000000..6375a48fa7
--- /dev/null
+++ b/challenge-221/ulrich-rieke/cpp/ch-2.cpp
@@ -0,0 +1,87 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <algorithm>
+#include <cmath>
+
+std::vector<std::string> split( const std::string & startline ,
+      const std::string & sep ) {
+  std::vector<std::string> separated ;
+  std::string::size_type start { 0 } ;
+  std::string::size_type pos ;
+  do {
+      pos = startline.find_first_of( sep , start ) ;
+      separated.push_back( startline.substr(start , pos - start )) ;
+      start = pos + 1 ;
+  } while ( pos != std::string::npos ) ;
+  return separated ;
+}
+
+std::string to_binary_string( int n , int len) {
+  std::string binstr ;
+  int total = n ;
+  while ( total != 0 ) {
+      binstr.append( std::to_string( total % 2 ) ) ;
+      total /= 2 ;
+  }
+  int difference = len - binstr.length( ) ;
+  if ( difference > 0 ) {
+      for ( int i = 0 ; i < difference ; i++ )
+    binstr.append( std::string( "0" ) ) ;
+  }
+  std::reverse( binstr.begin( ) , binstr.end( ) ) ;
+  return binstr ;
+}
+
+std::vector<int> extract( const std::vector<int> & numbers ,
+      const std::string & binstring ) {
+  std::vector<int> selection ;
+  for ( int i = 0 ; i < binstring.length( ) ; i++ ) {
+      if ( binstring.substr( i , 1 ) == "1" )
+    selection.push_back( numbers[ i ] ) ;
+  }
+  return selection ;
+}
+
+bool is_arithmetic( const std::vector<int> & aSeq ) {
+  int len = aSeq.size( ) ;
+  int start = aSeq[1] - aSeq[0] ;
+  for ( int i = 1 ; i < len - 1 ; i++ ) {
+      if ( aSeq[ i + 1 ] - aSeq[ i ] != start ) {
+    return false ;
+      }
+  }
+  return true ;
+}
+
+int main ( ) {
+  std::cout << "Enter some integers, separated by blanks!\n" ;
+  std::string line ;
+  std::getline( std::cin , line ) ;
+  std::vector<std::string> numberstrings ( split( line , " " ) ) ;
+  std::vector<int> numbers ;
+  for ( auto s : numberstrings )
+      numbers.push_back( std::stoi( s ) ) ;
+  int len = numbers.size( ) ;
+  if ( is_arithmetic( numbers ) )
+      std::cout << len << std::endl ;
+  else {
+      int maxlen = 0 ;
+      int limit = static_cast<int>( std::pow( 2.0 ,
+          static_cast<double>( len )) - 1 ) ;
+      for ( int i = 0 ; i < limit + 1 ; i++ ) {
+    std::string binstring ( to_binary_string( i , len ) ) ;
+    if ( std::count( binstring.begin( ) , binstring.end( ) ,
+          '1' ) > 1 ) {
+        std::vector<int> selection ( extract( numbers , binstring ) ) ;
+        if ( is_arithmetic( selection ) ) {
+          int sublen = selection.size( ) ;
+          if ( suble