- Added solutions by Roger Bell_West.

- Added solutions by Robert DiCicco.
- Added solutions by Ulrich Rieke.
- Added solutions by Laurent Rosenfeld.
- Added solutions by Niels van Dijke.
- Added solutions by Simon Proctor.
- Added solutions by Mark Anderson.
- Added solutions by Peter Meszaros.
- Added solutions by W. Luis Mochan.
- Added solutions by David Ferrone.
- Added solutions by Thomas Kohler.
- Added solutions by Stephen G. Lynn.
- Added solutions by Peter Campbell Smith.
- Added solutions by E. Choroba.
- Added solutions by Robbie Hatley.
- Added solutions by Jorg Sommrey.
- Added solutions by Cheok-Yin Fung.
- Added solutions by Robert Ransbottom.
- Added solutions by Flavio Poletti.
- Added solutions by Jaldhar H. Vyas.
- Added solutions by Avery Adams.
- Added solutions by Bob Lied.
- Added solutions by Athanasius.
- Added solutions by Simon Green.
- Added solutions by Jan Krnavek.
- Added solutions by Lubos Kolouch.
- Added solutions by BarrOff.
- Added solutions by Solathian.
- Added solutions by Matthias Muth.

52 files changed, 4970 insertions, 3346 deletions

diff --git a/challenge-220/eric-cheung/python/ch-1.py b/challenge-220/eric-cheung/python/ch-1.py
new file mode 100755
index 0000000000..5ee515aea5
--- /dev/null
+++ b/challenge-220/eric-cheung/python/ch-1.py
@@ -0,0 +1,17 @@
+

+## arrWordList = ["Perl", "Rust", "Raku"]  ## Example 1

+arrWordList = ["love", "live", "leave"]  ## Example 2

+

+arrOutputList = []

+

+for charLoop in arrWordList[0]:

+    bExist = True

+    for wordLoop in arrWordList[1:]:

+        if not charLoop in wordLoop.lower():

+            bExist = False

+            break

+    

+    if bExist:

+        arrOutputList.append(charLoop)

+

+print (arrOutputList)

diff --git a/challenge-220/eric-cheung/python/ch-2.py b/challenge-220/eric-cheung/python/ch-2.py
new file mode 100755
index 0000000000..9370992564
--- /dev/null
+++ b/challenge-220/eric-cheung/python/ch-2.py
@@ -0,0 +1,26 @@
+

+from itertools import permutations

+from math import sqrt

+

+def IsPerfectSqr (nInput):

+    dSqRoot = int(sqrt(nInput))

+    return (dSqRoot * dSqRoot == nInput)

+

+arrIntList = [1, 17, 8]  ## Example 1

+## arrIntList = [2, 2, 2]  ## Example 2

+

+arrOutputList = []

+

+arrPerm = set(permutations(arrIntList))

+

+for permLoop in list(arrPerm):

+    bIsSqrFul = True

+    for nIndx in range(0, len(permLoop) - 1):

+        if not IsPerfectSqr(permLoop[nIndx] + permLoop[nIndx + 1]):

+            bIsSqrFul = False

+            break

+

+    if bIsSqrFul and not permLoop in arrOutputList:

+        arrOutputList.append(permLoop)

+

+print (arrOutputList)

diff --git a/challenge-220/jeanluc2020/blog-1.txt b/challenge-220/jeanluc2020/blog.txt
index 9df40ba86f..9df40ba86f 100644
--- a/challenge-220/jeanluc2020/blog-1.txt
+++ b/challenge-220/jeanluc2020/blog.txt
diff --git a/challenge-220/jeanluc2020/blog-2.txt b/challenge-220/jeanluc2020/blog1.txt
index 4169e0e056..4169e0e056 100644
--- a/challenge-220/jeanluc2020/blog-2.txt
+++ b/challenge-220/jeanluc2020/blog1.txt
diff --git a/challenge-220/john-horner/README b/challenge-220/john-horner/README
new file mode 100644
index 0000000000..c860d6f0be
--- /dev/null
+++ b/challenge-220/john-horner/README
@@ -0,0 +1 @@
+Solutions by John Horner.
diff --git a/challenge-220/laurent-rosenfeld/blog.txt b/challenge-220/laurent-rosenfeld/blog.txt
new file mode 100644
index 0000000000..7d399e9609
--- /dev/null
+++ b/challenge-220/laurent-rosenfeld/blog.txt
@@ -0,0 +1 @@
+https://blogs.perl.org/users/laurent_r/2023/06/perl-weekly-challenge-220-common-characters.html
diff --git a/challenge-220/laurent-rosenfeld/blog1.txt b/challenge-220/laurent-rosenfeld/blog1.txt
new file mode 100644
index 0000000000..b29e61b761
--- /dev/null
+++ b/challenge-220/laurent-rosenfeld/blog1.txt
@@ -0,0 +1 @@
+https://blogs.perl.org/users/laurent_r/2023/06/perl-weekly-challenge-220-squareful-arrays.html
diff --git a/challenge-220/laurent-rosenfeld/perl/ch-1.pl b/challenge-220/laurent-rosenfeld/perl/ch-1.pl
new file mode 100644
index 0000000000..e311038510
--- /dev/null
+++ b/challenge-220/laurent-rosenfeld/perl/ch-1.pl
@@ -0,0 +1,18 @@
+use strict;
+use warnings;
+use feature 'say';
+
+sub common_char {
+    my %histo;
+    my @in = map lc $_, @_;
+    for my $word (@in) {
+        my %unique = map { $_ => 1 } split //, $word;
+        $histo{$_}++ for keys %unique;
+    }
+    return sort grep { $histo{$_} == scalar @in } keys %histo;
+}
+
+for my $test ([<Perl Rust Raku>], [<love live leave>]) {
+  printf "%-15s => ", "@$test";
+  say join " ", common_char @$test;
+}
diff --git a/challenge-220/laurent-rosenfeld/raku/ch-1.raku b/challenge-220/laurent-rosenfeld/raku/ch-1.raku
new file mode 100644
index 0000000000..306b69a061
--- /dev/null
+++ b/challenge-220/laurent-rosenfeld/raku/ch-1.raku
@@ -0,0 +1,8 @@
+sub common-char (@in) {
+    return sort keys ([∩] map {.lc.comb}, @in);
+}
+
+for <Perl Rust Raku>, <love live leave> -> @test {
+    printf "%-15s => ", "@test[]";
+    say common-char @test;
+}
diff --git a/challenge-220/laurent-rosenfeld/raku/ch-2.raku b/challenge-220/laurent-rosenfeld/raku/ch-2.raku
new file mode 100644
index 0000000000..c79d803297
--- /dev/null
+++ b/challenge-220/laurent-rosenfeld/raku/ch-2.raku
@@ -0,0 +1,17 @@
+sub is-squareful (@in) {
+    for @in.rotor(2 => -1) -> @list {
+        my $sum = [+] @list;
+        return False if ($sum.sqrt.Int)² != $sum;
+    }
+    return True;
+}
+sub find-squareful (@in) {
+    my $result = SetHash.new;
+    for @in.permutations -> $perm {
+        $result{"($perm)"}++ if is-squareful $perm;
+    }
+    return join ", ", $result.keys;
+}
+for <1 17 8>, <17 1 8>, <2 2 2> -> @test {
+    say @test, " => ",  find-squareful @test;
+}
diff --git a/challenge-220/perlboy1967/perl/ch1.pl b/challenge-220/perlboy1967/perl/ch-1.pl
index 29be6dc082..29be6dc082 100755
--- a/challenge-220/perlboy1967/perl/ch1.pl
+++ b/challenge-220/perlboy1967/perl/ch-1.pl
diff --git a/challenge-220/perlboy1967/perl/ch2.pl b/challenge-220/perlboy1967/perl/ch-2.pl
index c31e23c80e..c31e23c80e 100755
--- a/challenge-220/perlboy1967/perl/ch2.pl
+++ b/challenge-220/perlboy1967/perl/ch-2.pl
diff --git a/challenge-220/robert-dicicco/julia/ch-1.jl b/challenge-220/robert-dicicco/julia/ch-1.jl
new file mode 100644
index 0000000000..0c1ac773ed
--- /dev/null
+++ b/challenge-220/robert-dicicco/julia/ch-1.jl
@@ -0,0 +1,49 @@
+#!/usr/bin/env julia
+#=
+------------------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-05
+Challenge 220 Task 1 common Characters ( Julia )
+------------------------------------------------
+=#
+
+using Printf
+
+words = [["Perl", "Rust", "Raku"], ["love", "live", "leave"]]
+alphabet_hash = Dict()
+
+for wds in words
+    for c in 'a':'z'
+        alphabet_hash[c] = 0
+    end
+    @printf("Input: @words = %s\n",wds)
+    for wd in wds
+        for ch in lowercase(wd)
+             alphabet_hash[ch] += 1
+        end
+    end
+    @printf("Output: ")
+    # Print the dictionary
+    for (key, value) in alphabet_hash
+        if value >= 3
+            @printf("%s ",key)
+        end
+    end
+    println("\n")
+end
+
+#=
+------------------------------------------------
+julia .\CommonChars.jl
+
+Input: @words = ["Perl", "Rust", "Raku"]
+Output: r
+
+Input: @words = ["love", "live", "leave"]
+Output: e v l
+------------------------------------------------
+=#
+
+
+
+
diff --git a/challenge-220/robert-dicicco/julia/ch-2.jl b/challenge-220/robert-dicicco/julia/ch-2.jl
new file mode 100644
index 0000000000..4bbd962ba8
--- /dev/null
+++ b/challenge-220/robert-dicicco/julia/ch-2.jl
@@ -0,0 +1,59 @@
+#!/usr/bin/env julia
+#=
+------------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-08
+Challenge 220 Task 2 Squareful ( Julia )
+------------------------------------------
+=#
+using Printf
+using Combinatorics
+
+myints = [[1,8,17],[1,8,17,19]]
+
+p=[]
+
+function IsPerfectSquare(number_to_test)
+    root = floor(sqrt(number_to_test))
+    if ((root ^ 2 ) == number_to_test)
+        return true;
+    end
+    return false;
+end
+
+for intsub in myints
+    @printf("Input: @ints = %s\n",intsub)
+    ln = length(intsub)
+    @printf("Output: ")
+    global p = collect(permutations(intsub))
+    ln = length(intsub)
+    for perm in p
+        tv = 1
+        flag = 0
+        while tv < ln
+              if IsPerfectSquare(perm[tv] + perm[tv + 1])
+               flag += 1
+            else
+                flag = 0
+            end
+            tv += 1
+        end
+        if flag == ln - 1
+            @printf("%s ",perm)
+        end
+    end
+    println("\n")
+end
+
+#=
+------------------------------------------
+SAMPLE OUTPUT
+julia .\Squareful.jl
+
+Input: @ints = [1, 8, 17]
+Output: [1, 8, 17] [17, 8, 1]
+
+Input: @ints = [1, 8, 17, 19]
+Output: [1, 8, 17, 19] [19, 17, 8, 1]
+------------------------------------------
+=#
diff --git a/challenge-220/robert-dicicco/perl/ch-1.pl b/challenge-220/robert-dicicco/perl/ch-1.pl
new file mode 100644
index 0000000000..67cde25402
--- /dev/null
+++ b/challenge-220/robert-dicicco/perl/ch-1.pl
@@ -0,0 +1,62 @@
+#!/usr/bin/env perl
+=begin comment
+------------------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-05
+Challenge 220 Task 1 common Characters ( Perl )
+------------------------------------------------
+=cut
+use strict;
+use warnings;
+use feature 'say';
+
+my @words = (["Perl", "Rust", "Raku"], ["love", "live", "leave"]);
+
+my $cnt = 0;
+my $str = '';
+my %found = ();
+my $arrlen = 0;
+
+for (my $wd = 0; $wd < scalar @words; $wd ++ ) {
+    $arrlen = scalar @{$words[$wd]};
+    $str = join('', "a".."z");
+    $cnt = 0;
+
+    my $arrelem = 0;
+    print("Input: \@words = ");
+    while($arrelem < $arrlen){
+        print("$words[$wd][$arrelem] ");
+        $arrelem++;
+    }
+    print("\n");
+
+    while ($cnt < length($str)) {
+        my $ch = substr($str, $cnt++, 1);
+        if ((lc($words[$wd][0]) =~ /$ch/) and (lc($words[$wd][1]) =~ /$ch/) and (lc($words[$wd][2]) =~ /$ch/)) {
+            $found{$ch} = 1;
+        }
+    }
+
+    my @arr = ();
+    print("Output: ");
+    for my $key (keys %found) {
+        push(@arr,$key);
+    }
+    my $str = join(",",sort(@arr));
+    print("\($str\)\n\n");
+    %found = ();
+}
+
+=begin comment
+------------------------------------------------
+SAMPLE OUTPUT
+perl .\CommonChars.pl
+
+Input: @words = Perl Rust Raku
+Output: (r)
+
+Input: @words = love live leave
+Output: (e,l,v)
+------------------------------------------------
+=cut
+
diff --git a/challenge-220/robert-dicicco/perl/ch-2.pl b/challenge-220/robert-dicicco/perl/ch-2.pl
new file mode 100644
index 0000000000..1b7bdc94b7
--- /dev/null
+++ b/challenge-220/robert-dicicco/perl/ch-2.pl
@@ -0,0 +1,60 @@
+#!#!/usr/bin/env perl
+=begin comment
+------------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-0-6-07
+Challenge 220 Task 2 Squareful ( Perl )
+------------------------------------------
+=cut
+use strict;
+use warnings;
+use feature 'say';
+use Algorithm::Permute qw/permute/;
+
+my @ints = (1,8,17);
+my $flag = 0;
+my $elems = $#ints;
+
+sub IsPerfectSquare {
+    my $number_to_test = shift;
+    my $root = int(sqrt($number_to_test));
+    if (($root ** 2 ) == $number_to_test) {
+        return 1;
+    }
+    return undef;
+}
+
+say "Input: \@ints = @ints";
+
+# print all permutations of @ints
+print("Output: ");
+my $p = Algorithm::Permute->new(\@ints);
+while ( my @perm = $p->next ) {
+    for (my $tv = 0; $tv < $#perm; $tv++) {
+        if (IsPerfectSquare($perm[$tv] + $perm[$tv+1])) {
+            $flag += 1;
+        } else {
+            $flag = 0;
+        }
+    }
+
+    if ($flag == $elems) {
+        print("(@perm) ");
+    }
+    $flag = 0;
+}
+
+print("\n");
+
+=begin comment
+------------------------------------------
+SAMPLE OUTPUT
+perl .\Squareful.pl
+
+Input: @ints = 1 8 17
+Output: (17 8 1) (1 8 17)
+
+Input: @ints = 1 8 17 19
+Output: (19 17 8 1) (1 8 17 19)
+------------------------------------------
+=cut
diff --git a/challenge-220/robert-dicicco/python/ch-1.py b/challenge-220/robert-dicicco/python/ch-1.py
new file mode 100644
index 0000000000..632e169c46
--- /dev/null
+++ b/challenge-220/robert-dicicco/python/ch-1.py
@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+# ------------------------------------------------
+# AUTHOR: Robert DiCicco
+# DATE  : 2023-06-05
+# Challenge 220 Task 1 common Characters ( Python )
+# ------------------------------------------------
+
+words = [["Perl", "Rust", "Raku"], ["love", "live", "leave"]]
+
+alphabet_hash = {}
+
+for wds in words:
+    for char in range(ord('a'), ord('z')+1):
+        alphabet_hash[chr(char)] = 0
+
+    print("Input: @words = ",wds)
+    for wd in wds:
+        wd = wd.lower()
+        for ch in wd:
+            alphabet_hash[ch] += 1
+
+    print("Output: ",end= " ")
+    for i in alphabet_hash:
+        if alphabet_hash[i] >= 3:
+            print(i,end=" ")
+    print("\n")
+
+# ------------------------------------------------
+# SAMPLE OUTPUT
+# python .\CommonChars.py
+
+# Input: @words =  ['Perl', 'Rust', 'Raku']
+# Output:  r
+
+# Input: @words =  ['love', 'live', 'leave']
+# Output:  e l v
+
+# ------------------------------------------------
diff --git a/challenge-220/robert-dicicco/python/ch-2.py b/challenge-220/robert-dicicco/python/ch-2.py
new file mode 100644
index 0000000000..550194cb55
--- /dev/null
+++ b/challenge-220/robert-dicicco/python/ch-2.py
@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+# ------------------------------------------
+# AUTHOR: Robert DiCicco
+# DATE  : 2023-06-00
+# Challenge 220 Task 2 Squareful ( Python )
+# ------------------------------------------
+import math
+from itertools import permutations
+
+
+myints = [[1,8,17],[1,8,17,19]]
+
+def IsPerfectSquare(number_to_test) :
+    root = math.floor(math.sqrt(number_to_test))
+    if ((root ** 2 ) == number_to_test) :
+        return True;
+    return False;
+
+for intsub in myints:
+    print("Input: @ints = ",intsub)
+    print("OutPut: ",end="")
+    perm = permutations(intsub)
+    for i in list(perm):
+        ln = len(i) - 1
+        tv = 0
+        flag = 0
+        while tv < ln :
+            if IsPerfectSquare(i[tv] + i[tv + 1]) :
+                flag += 1
+            else :
+                flag = 0
+            tv += 1
+        if flag == ln - 1 :
+             print(i,end=" ")
+    print("\n")
+
+#------------------------------------------
+# SAMPLE OUTPUT
+# python .\Squareful.py
+
+# Input: @ints =  [1, 8, 17]
+# OutPut: (1, 17, 8) (17, 1, 8)
+
+# Input: @ints =  [1, 8, 17, 19]
+# OutPut: (1, 19, 17, 8) (19, 1, 8, 17)
+#------------------------------------------
+
+
+
diff --git a/challenge-220/robert-dicicco/raku/ch-1.raku b/challenge-220/robert-dicicco/raku/ch-1.raku
new file mode 100644
index 0000000000..4180a77bd3
--- /dev/null
+++ b/challenge-220/robert-dicicco/raku/ch-1.raku
@@ -0,0 +1,59 @@
+#!/usr/bin/env raku
+=begin comment
+------------------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-05
+Challenge 220 Task 1 common Characters ( Raku )
+------------------------------------------------
+=end comment
+
+use v6;
+
+my @words = <Perl Rust Raku>, <love live leave>;
+
+my $str = join('', "a".."z");
+
+for (@words) -> @wds {
+    say "Input: \@words = ", @wds;
+    my $sz = @wds.elems;    # number of words in each entry
+    my $cnt = 0;
+    my %found = ();         # hash to hold results
+    my @out = ();           # array to hold output;
+    while $cnt < $sz {      # for each one of the word entries
+        my $strcnt = 0;
+        while $strcnt < $str.chars {
+            my $ch = substr($str, $strcnt++,1);
+            my $arrch = lc(join('',@wds[$cnt]));
+            if $arrch.contains($ch) {       # check to see if entry holds character
+                if defined %found{$ch} {    # bump its count
+                    %found{$ch}++
+                } else {
+                    %found{$ch} = 1;        # add it to the hash array
+                }
+            }
+        }
+        $cnt++;         # get next word
+    }
+    for %found.kv -> $k, $v {           # for keys, values in hash
+        @out.push: $k if $v == $sz;     # push the key to @out array if in all words
+    }
+    say "Output: ",@out.sort;           # and say the results
+    say " ";
+}
+
+=begin comment
+------------------------------------------------
+SAMPLE OUTPUT
+raku .\CommonChars.rk
+
+Input: @words = (Perl Rust Raku)
+Output: (r)
+
+Input: @words = (love live leave)
+Output: (e l v)
+
+------------------------------------------------
+=end comment
+
+
+
diff --git a/challenge-220/robert-dicicco/raku/ch-2.raku b/challenge-220/robert-dicicco/raku/ch-2.raku
new file mode 100644
index 0000000000..4010124aa4
--- /dev/null
+++ b/challenge-220/robert-dicicco/raku/ch-2.raku
@@ -0,0 +1,43 @@
+#!/usr/bin/env raku
+use v6;
+=begin comment
+------------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-08
+Challenge 220 Task 2 Squareful ( Raku )
+------------------------------------------
+=end comment
+
+my @ints = <1 8 17>,<1 8 17 19>;
+
+sub IsPerfectSquare($number_to_test) {
+    my $root = $number_to_test.sqrt.Int;
+    if (($root ** 2 ) == $number_to_test) {
+        return True;
+    }
+    return False;
+}
+
+for (@ints) -> @intsub {
+    say "Input: \@ints = ",@intsub;
+    print("Output: ");
+    for (@intsub.permutations) -> @perm {
+        my $tv = 0;
+        my $flag = 0;
+        while $tv < @intsub.elems - 1 {
+            if (IsPerfectSquare(@perm[$tv] + @perm[$tv+1])) {
+                $flag += 1;
+            } else {
+                $flag = 0;
+            }
+            $tv++;
+        }
+        if ($flag == (@intsub.elems - 1)) {
+            print("(" ~ @perm ~ ") ");
+        }
+    }
+    print("\n\n");
+}
+
+
+
diff --git a/challenge-220/robert-dicicco/ruby/ch-1.rb b/challenge-220/robert-dicicco/ruby/ch-1.rb
new file mode 100644
index 0000000000..d825f52ca7
--- /dev/null
+++ b/challenge-220/robert-dicicco/ruby/ch-1.rb
@@ -0,0 +1,51 @@
+#!/usr/bin/env ruby
+=begin
+------------------------------------------------
+AUTHOR: Robert DiCicco
+DATE  : 2023-06-05
+Challenge 220 Task 1 common Characters ( Ruby )
+------------------------------------------------
+=end
+
+words = [["Perl", "Rust", "Raku"], ["love", "live", "leave"]];
+
+str = ('a' .. 'z')
+
+alphabet_hash = {}
+
+words.each do |wds|
+    str.each do |letter|
+        alphabet_hash[letter] = 0
+    end
+    puts("Input: @words = #{wds}")
+    wds.each do |wd|