- Added solutions by Ryan Thompson.

- Added solutions by Reinier Maliepaard.

26 files changed, 3143 insertions, 3042 deletions

diff --git a/challenge-280/reinier-maliepaard/blog.txt b/challenge-280/reinier-maliepaard/blog.txt
new file mode 100644
index 0000000000..cab97a0bb1
--- /dev/null
+++ b/challenge-280/reinier-maliepaard/blog.txt
@@ -0,0 +1 @@
+https://reiniermaliepaard.nl/perl/pwc/index.php?id=pwc280
diff --git a/challenge-280/reinier-maliepaard/perl/ch-1.pl b/challenge-280/reinier-maliepaard/perl/ch-1.pl
new file mode 100644
index 0000000000..1ea18dd7db
--- /dev/null
+++ b/challenge-280/reinier-maliepaard/perl/ch-1.pl
@@ -0,0 +1,33 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+sub twice_appearance {
+
+    my %found = ();
+
+    foreach my $char ( split(//, $_[0]) ) {
+        return($char) if ($found{$char});
+        $found{$char} = 1;
+    }
+    # return -1 if no duplicate is found
+    return(-1);
+}
+
+# Tests
+
+my $str;
+
+# Example 1
+$str = "acbddbca";
+print(twice_appearance($str), "\n"); # Output: "d"
+
+# Example 2
+$str = "abccd";
+print(twice_appearance($str), "\n"); # Output: "c"
+
+# Example 3
+$str = "abcdabbb";
+print(twice_appearance($str), "\n"); # Output: "a"
+
+# Study: https://reiniermaliepaard.nl/perl/part-2/index.php?id=useful_hash
diff --git a/challenge-280/reinier-maliepaard/perl/ch-2.pl b/challenge-280/reinier-maliepaard/perl/ch-2.pl
new file mode 100644
index 0000000000..77b9fdf10c
--- /dev/null
+++ b/challenge-280/reinier-maliepaard/perl/ch-2.pl
@@ -0,0 +1,29 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+sub count_asterisks {
+
+    # Remove the content within each pair of vertical bars
+    $_[0] =~ s/\|[^|]*\|//g;
+
+    # Count the remaining asterisks
+    # see 11.3 on https://reiniermaliepaard.nl/perl/part-1/index.php?id=transliteration
+    return( $_[0] =~ tr/*/*/ );
+}
+
+# Tests
+
+my $str;
+
+# Example 1
+$str = "p|*e*rl|w**e|*ekly|";
+print(count_asterisks($str), "\n"); # Output: 2
+
+# Example 2
+$str = "perl";
+print(count_asterisks($str), "\n"); # Output: 0
+
+# Example 3
+$str = "th|ewe|e**|k|l***ych|alleng|e";
+print(count_asterisks($str), "\n"); # Output: 5
diff --git a/stats/pwc-challenge-277.json b/stats/pwc-challenge-277.json
index 04d2a683b0..25d938bf57 100644
--- a/stats/pwc-challenge-277.json
+++ b/stats/pwc-challenge-277.json
@@ -1,233 +1,4 @@
 {
-   "series" : [
-      {
-         "data" : [
-            {
-               "name" : "Alexander Karelas",
-               "y" : 2,
-               "drilldown" : "Alexander Karelas"
-            },
-            {
-               "y" : 5,
-               "drilldown" : "Ali Moradi",
-               "name" : "Ali Moradi"
-            },
-            {
-               "drilldown" : "Andrew Schneider",
-               "y" : 3,
-               "name" : "Andrew Schneider"
-            },
-            {
-               "y" : 3,
-               "drilldown" : "Arne Sommer",
-               "name" : "Arne Sommer"
-            },
-            {
-               "y" : 4,
-               "drilldown" : "Athanasius",
-               "name" : "Athanasius"
-            },
-            {
-               "name" : "BarrOff",
-               "y" : 2,
-               "drilldown" : "BarrOff"
-            },
-            {
-               "name" : "Bob Lied",
-               "drilldown" : "Bob Lied",
-               "y" : 2
-            },
-            {
-               "y" : 5,
-               "drilldown" : "Bruce Gray",
-               "name" : "Bruce Gray"
-            },
-            {
-               "drilldown" : "Cheok-Yin Fung",
-               "y" : 2,
-               "name" : "Cheok-Yin Fung"
-            },
-            {
-               "drilldown" : "Dave Jacoby",
-               "y" : 2,
-               "name" : "Dave Jacoby"
-            },
-            {
-               "y" : 2,
-               "drilldown" : "David Ferrone",
-               "name" : "David Ferrone"
-            },
-            {
-               "y" : 2,
-               "drilldown" : "E. Choroba",
-               "name" : "E. Choroba"
-            },
-            {
-               "name" : "Feng Chang",
-               "y" : 2,
-               "drilldown" : "Feng Chang"
-            },
-            {
-               "name" : "Jaldhar H. Vyas",
-               "drilldown" : "Jaldhar H. Vyas",
-               "y" : 5
-            },
-            {
-               "name" : "Jan Krnavek",
-               "y" : 2,
-               "drilldown" : "Jan Krnavek"
-            },
-            {
-               "drilldown" : "Jorg Sommrey",
-               "y" : 3,
-               "name" : "Jorg Sommrey"
-            },
-            {
-               "y" : 2,
-               "drilldown" : "Kjetil Skotheim",
-               "name" : "Kjetil Skotheim"
-            },
-            {
-               "name" : "Laurent Rosenfeld",
-               "y" : 6,
-               "drilldown" : "Laurent Rosenfeld"
-            },
-            {
-               "name" : "Luca Ferrari",
-               "y" : 12,
-               "drilldown" : "Luca Ferrari"
-            },
-            {
-               "name" : "Mariano Ortega",
-               "y" : 2,
-               "drilldown" : "Mariano Ortega"
-            },
-            {
-               "drilldown" : "Mark Anderson",
-               "y" : 2,
-               "name" : "Mark Anderson"
-            },
-            {
-               "drilldown" : "Matthew Neleigh",
-               "y" : 2,
-               "name" : "Matthew Neleigh"
-            },
-            {
-               "y" : 3,
-               "drilldown" : "Matthias Muth",
-               "name" : "Matthias Muth"
-            },
-            {
-               "drilldown" : "Nelo Tovar",
-               "y" : 2,
-               "name" : "Nelo Tovar"
-            },
-            {
-               "drilldown" : "Niels van Dijke",
-               "y" : 2,
-               "name" : "Niels van Dijke"
-            },
-            {
-               "name" : "Packy Anderson",
-               "drilldown" : "Packy Anderson",
-               "y" : 5
-            },
-            {
-               "name" : "Peter Campbell Smith",
-               "y" : 3,
-               "drilldown" : "Peter Campbell Smith"
-            },
-            {
-               "name" : "Peter Meszaros",
-               "drilldown" : "Peter Meszaros",
-               "y" : 2
-            },
-            {
-               "name" : "Reinier Maliepaard",
-               "y" : 3,
-               "drilldown" : "Reinier Maliepaard"
-            },
-            {
-               "drilldown" : "Robbie Hatley",
-               "y" : 3,
-               "name" : "Robbie Hatley"
-            },
-            {
-               "drilldown" : "Robert Ransbottom",
-               "y" : 2,
-               "name" : "Robert Ransbottom"
-            },
-            {
-               "name" : "Roger Bell_West",
-               "drilldown" : "Roger Bell_West",
-               "y" : 5
-            },
-            {
-               "name" : "Santiago Leyva",
-               "y" : 2,
-               "drilldown" : "Santiago Leyva"
-            },
-            {
-               "drilldown" : "Simon Green",
-               "y" : 3,
-               "name" : "Simon Green"
-            },
-            {
-               "drilldown" : "Thomas Kohler",
-               "y" : 4,
-               "name" : "Thomas Kohler"
-            },
-            {
-               "drilldown" : "Ulrich Rieke",
-               "y" : 4,
-               "name" : "Ulrich Rieke"
-            },
-            {
-               "y" : 3,
-               "drilldown" : "W. Luis Mochan",
-               "name" : "W. Luis Mochan"
-            },
-            {
-               "name" : "Wanderdoc",
-               "drilldown" : "Wanderdoc",
-               "y" : 2
-            }
-         ],
-         "name" : "The Weekly Challenge - 277",
-         "colorByPoint" : 1
-      }
-   ],
-   "xAxis" : {
-      "type" : "category"
-   },
-   "plotOptions" : {
-      "series" : {
-         "borderWidth" : 0,
-         "dataLabels" : {
-            "enabled" : 1,
-            "format" : "{point.y}"
-         }
-      }
-   },
-   "title" : {
-      "text" : "The Weekly Challenge - 277"
-   },
-   "chart" : {
-      "type" : "column"
-   },
-   "tooltip" : {
-      "pointFormat" : "<span style='color:{point.color}'>{point.name}</span>: <b>{point.y:f}</b><br/>",
-      "followPointer" : 1,
-      "headerFormat" : "<span style='font-size:11px'>{series.name}</span><br/>"
-   },
-   "subtitle" : {
-      "text" : "[Champions: 38] Last updated at 2024-07-29 17:29:09 GMT"
-   },
-   "yAxis" : {
-      "title" : {
-         "text" : "Total Solutions"
-      }
-   },
    "drilldown" : {
       "series" : [
          {
@@ -242,7 +13,6 @@
          },
          {
             "id" : "Ali Moradi",
-            "name" : "Ali Moradi",
             "data" : [
                [
                   "Perl",
@@ -256,9 +26,11 @@
                   "Blog",
                   1
                ]
-            ]
+            ],
+            "name" : "Ali Moradi"
          },
          {
+            "id" : "Andrew Schneider",
             "data" : [
                [
                   "Perl",
@@ -269,7 +41,6 @@
                   1
                ]
             ],
-            "id" : "Andrew Schneider",
             "name" : "Andrew Schneider"
          },
          {
@@ -287,8 +58,6 @@
             ]
          },
          {
-            "id" : "Athanasius",
-            "name" : "Athanasius",
             "data" : [
                [
                   "Perl",
@@ -298,29 +67,33 @@
                   "Raku",
                   2
                ]
-            ]
+            ],
+            "name" : "Athanasius",
+            "id" : "Athanasius"
          },
          {
+            "id" : "BarrOff",
+            "name" : "BarrOff",
             "data" : [
                [
                   "Raku",
                   2
                ]
-            ],
-            "id" : "BarrOff",
-            "name" : "BarrOff"
+            ]
          },
          {
+            "name" : "Bob Lied",
             "data" : [
                [
                   "Perl",
                   2
                ]
             ],
-            "name" : "Bob Lied",
             "id" : "Bob Lied"
          },
          {
+            "id" : "Bruce Gray",
+            "name" : "Bruce Gray",
             "data" : [
                [
                   "Perl",
@@ -334,28 +107,26 @@
                   "Blog",
                   1
                ]
-            ],
-            "name" : "Bruce Gray",
-            "id" : "Bruce Gray"
+            ]
          },
          {
+            "id" : "Cheok-Yin Fung",
+            "name" : "Cheok-Yin Fung",
             "data" : [
                [
                   "Perl",
                   2
                ]
-            ],
-            "id" : "Cheok-Yin Fung",
-            "name" : "Cheok-Yin Fung"
+            ]
          },
          {
+            "id" : "Dave Jacoby",
             "data" : [
                [
                   "Perl",
                   2
                ]
             ],
-            "id" : "Dave Jacoby",
             "name" : "Dave Jacoby"
          },
          {
@@ -369,8 +140,8 @@
             "id" : "David Ferrone"
          },
          {
-            "name" : "E. Choroba",
             "id" : "E. Choroba",
+            "name" : "E. Choroba",
             "data" : [
                [
                   "Perl",
@@ -379,16 +150,17 @@
             ]
          },
          {
-            "name" : "Feng Chang",
-            "id" : "Feng Chang",
             "data" : [
                [
                   "Raku",
                   2
                ]
-            ]
+            ],
+            "name" : "Feng Chang",
+            "id" : "Feng Chang"
          },
          {
+            "id" : "Jaldhar H. Vyas",
             "data" : [
                [
                   "Perl",
@@ -403,20 +175,20 @@
                   1
                ]
             ],
-            "id" : "Jaldhar H. Vyas",
             "name" : "Jaldhar H. Vyas"
          },
          {
             "name" : "Jan Krnavek",
-            "id" : "Jan Krnavek",
             "data" : [
                [
                   "Raku",
                   2
                ]
-            ]
+            ],
+            "id" : "Jan Krnavek"
          },
          {
+            "name" : "Jorg Sommrey",
             "data" : [
                [
                   "Perl",
@@ -427,20 +199,21 @@
                   1
                ]
             ],
-            "name" : "Jorg Sommrey",
             "id" : "Jorg Sommrey"
          },
          {
-            "id" : "Kjetil Skotheim",
             "name" : "Kjetil Skotheim",
             "data" : [
                [
                   "Perl",
                   2
                ]
-            ]
+            ],
+            "id" : "Kjetil Skotheim"
          },
          {
+            "id" : "Laurent Rosenfeld",
+            "name" : "Laurent Rosenfeld",
             "data" : [
                [
                   "Perl",
@@ -454,13 +227,9 @@
                   "Blog",
                   2
                ]
-            ],
-            "name" : "Laurent Rosenfeld",
-            "id" : "Laurent Rosenfeld"
+            ]
          },
          {
-            "id" : "Luca Ferrari",
-            "name" : "Luca Ferrari",
             "data" : [
                [
                   "Raku",
@@ -470,27 +239,29 @@
                   "Blog",
                   10
                ]
-            ]
+            ],
+            "name" : "Luca Ferrari",
+            "id" : "Luca Ferrari"
          },
          {
-            "name" : "Mariano Ortega",
-            "id" : "Mariano Ortega",
             "data" : [
                [
                   "Perl",
                   2
                ]
-            ]
+            ],
+            "name" : "Mariano Ortega",
+            "id" : "Mariano Ortega"
          },
          {
             "id" : "Mark Anderson",
-            "name" : "Mark Anderson",
             "data" : [
                [
                   "Raku",
                   2
                ]
-            ]
+            ],
+            "name" : "Mark Anderson"
          },
          {
             "id" : "Matthew Neleigh",
@@ -503,6 +274,8 @@
             ]
          },
          {
+            "id" : "Matthias Muth",
+            "name" : "Matthias Muth",
             "data" : [
                [
                   "Perl",
@@ -512,31 +285,30 @@
                   "Blog",
                   1
                ]
-            ],
-            "name" : "Matthias Muth",
-            "id" : "Matthias Muth"
+            ]
          },
          {
+            "name" : "Nelo Tovar",
             "data" : [
                [
                   "Perl",
                   2
                ]
             ],
-            "name" : "Nelo Tovar",
             "id" : "Nelo Tovar"
          },
          {
+            "name" : "Niels van Dijke",
             "data" : [
                [
                   "Perl",
                   2
                ]
             ],
-            "id" : "Niels van Dijke",
-            "name" : "Niels van Dijke"
+            "id" : "Niels van Dijke"
          },
          {
+            "name" : "Packy Anderson",
             "data" : [
                [
                   "Perl",
@@ -551,7 +323,6 @@
                   1
                ]
             ],
-            "name" : "Packy Anderson",
             "id" : "Packy Anderson"
          },
          {
@@ -579,6 +350,7 @@
             "id" : "Peter Meszaros"
          },
          {
+            "name" : "Reinier Maliepaard",
             "data" : [
                [
                   "Perl",
@@ -589,10 +361,11 @@
                   1
                ]
             ],
-            "name" : "Reinier Maliepaard",
             "id" : "Reinier Maliepaard"
          },
          {
+            "id" : "Robbie Hatley",
+            "name" : "Robbie Hatley",
             "data" : [
                [
                   "Perl",
@@ -602,22 +375,19 @@
                   "Blog",
                   1
                ]
-            ],
-            "name" : "Robbie Hatley",
-            "id" : "Robbie Hatley"
+            ]
          },
          {
-            "name" : "Robert Ransbottom",
-            "id" : "Robert Ransbottom",
             "data" : [
                [
                   "Raku",
                   2
                ]
-            ]
+            ],
+            "name" : "Robert Ransbottom",
+            "id" : "Robert Ransbottom"
          },
          {
-            "name" : "Roger Bell_West",
             "id" : "Roger Bell_West",
             "data" : [
                [
@@ -632,21 +402,34 @@
                   "Blog",
                   1
                ]
+            ],
+            "name" : "Roger Bell_West"
+         },
+         {
+            "id" : "Ryan Thompson",
+            "name" : "Ryan Thompson",
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
             ]
          },
          {
             "id" : "Santiago Leyva",
-            "name" : "Santiago Leyva",
             "data" : [
                [
                   "Perl",
                   2
                ]
-            ]
+            ],
+            "name" : "Santiago Leyva"
          },
          {
-            "name" : "Simon Green",
-            "id" : "Simon Green",
             "data" : [
                [
                   "Perl",
@@ -656,9 +439,12 @@
                   "Blog",
                   1
                ]
-            ]
+            ],
+            "name" : "Simon Green",
+            "id" : "Simon Green"
          },
          {
+            "name" : "Thomas Kohler",
             "data" : [
                [
                   "Perl",
@@ -669,8 +455,7 @@
                   2
                ]
             ],
-            "id" : "Thomas Kohler",
-            "name" : "Thomas Kohler"
+            "id" : "Thomas Kohler"
          },
          {
             "data" : [
@@ -683,10 +468,11 @@
                   2
                ]
             ],
-            "id" : "Ulrich Rieke",
-            "name" : "Ulrich Rieke"
+            "name" : "Ulrich Rieke",
+            "id" : "Ulrich Rieke"
          },
          {
+            "name" : "W. Luis Mochan",
             "data" : [
                [
                   "Perl",
@@ -697,22 +483,255 @@
                   1
                ]
             ],
-            "id" : "W. Luis Mochan",
-            "name" : "W. Luis Mochan"
+            "id" : "W. Luis Mochan"
          },
          {
-            "id" : "Wanderdoc",
-            "name" : "Wanderdoc",
             "data" : [
                [
                   "Perl",
                   2
                ]
-            ]
+            ],
+            "name" : "Wanderdoc",
+            "id" : "Wanderdoc"
          }
       ]
    },
+   "tooltip" : {
+      "pointFormat" : "<span style='color:{point.color}'>{point.name}</span>: <b>{point.y:f}</b><br/>",
+      "headerFormat" : "<span style='font-size:11px'>{series.name}</span><br/>",
+      "followPointer" : 1
+   },
+   "subtitle" : {
+      "text" : "[Champions: 39] Last updated at 2024-07-31 16:00:46 GMT"
+   },
    "legend" : {
       "enabled" : 0
-   }
+   },
+   "title" : {
+      "text" : "The Weekly Challenge - 277"
+   },
+   "yAxis" : {
+      "title" : {
+         "text" : "Total Solutions"
+      }
+   },
+   "plotOptions" : {
+      "series" : {
+         "dataLabels" : {
+            "enabled" : 1,
+            "format" : "{point.y}"
+         },
+         "borderWidth" : 0
+      }
+   },
+   "xAxis" : {
+      "type" : "category"
+   },
+   "chart" : {
+      "type" : "column"
+   },
+   "series" : [
+      {
+         "name" : "The Weekly Challenge - 277",
+         "data" : [
+            {
+               "drilldown" : "Alexander Karelas",
+               "name" : "Alexander Karelas",
+               "y" : 2
+            },
+            {
+               "y" : 5,
+               "drilldown" : "Ali Moradi",
+               "name" : "Ali Moradi"
+            },
+            {
+               "name" : "Andrew Schneider",
+               "drilldown" : "Andrew Schneider",
+               "y" : 3
+            },
+            {
+               "name" : "Arne Sommer",
+               "drilldown" : "Arne Sommer",
+               "y" : 3
+            },
+            {
+               "drilldown" : "Athanasius",
+               "name" : "Athanasius",
+               "y" : 4
+            },
+            {
+               "y" : 2,
+               "drilldown" : "BarrOff",
+               "name" : "BarrOff"
+            },
+            {
+               "drilldown" : "Bob Lied",
+               "name" : "Bob Lied",
+               "y" : 2
+            },
+            {
+               "y" : 5,
+               "name" : "Bruce Gray",
+               "drilldown" : "Bruce Gray"
+            },
+            {
+               "drilldown" : "Cheok-Yin Fung",
+               "name" : "Cheok-Yin Fung",
+               "y" : 2
+            },
+            {
+               "y" : 2,
+               "name" : "Dave Jacoby",
+               "drilldown" : "Dave Jacoby"
+            },
+            {
+               "name" : "David Ferrone",
+               "drilldown" : "David Ferrone",
+               "y" : 2
+            },
+            {
+               "drilldown" : "E. Choroba",
+               "name" : "E. Choroba",
+               "y" : 2
+            },
+            {
+               "y" : 2,
+               "drilldown" : "Feng Chang",
+               "name" : "Feng Chang"
+            },
+            {
+               "name" : "Jaldhar H. Vyas",
+               "drilldown" : "Jaldhar H. Vyas",
+               "y" : 5
+            },
+            {
+               "y" : 2,
+               "name" : "Jan Krnavek",
+               "drilldown" : "Jan Krnavek"
+            },
+            {
+               "y" : 3,
+               "name" : "Jorg Sommrey",
+               "drilldown" : "Jorg Sommrey"
+            },
+            {
+               "name" : "Kjetil Skotheim",
+               "drilldown" : "Kjetil Skotheim",
+               "y" : 2
+            },
+            {
+               "drilldown" : "Laurent Rosenfeld",
+               "name" : "Laurent Rosenfeld",
+               "y" : 6
+            },
+            {
+               "y" : 12,
+               "name" : "Luca Ferrari",
+               "drilldown" : "Luca Ferrari"
+            },
+            {
+               "y" : 2,
+               "drilldown" : "Mariano Ortega",
+               "name" : "Mariano Ortega"
+            },
+            {
+               "name" : "Mark Anderson",
+               "drilldown" : "Mark Anderson",
+               "y" : 2
+            },
+            {
+               "name" : "Matthew Neleigh",
+               "drilldown" : "Matthew Neleigh",
+               "y" : 2
+            },
+            {
+               "drilldown" : "Matthias Muth",
+               "name" : "Matthias Muth",
+               "y" : 3
+            },
+            {
+               "name" : "Nelo Tovar",
+               "drilldown" : "Nelo Tovar",
+               "y" : 2
+            },
+            {
+               "drilldown" : "Niels van Dijke",
+               "name" : "Niels van Dijke",
+               "y" : 2
+            },
+            {
+               "y" : 5,
+               "name" : "Packy Anderson",
+               "drilldown" : "Packy Anderson"
+            },
+            {
+               "drilldown" : "Peter Campbell Smith",
+               "name" : "Peter Campbell Smith",
+               "y" : 3
+            },
+            {
+               "y" : 2,
+               "drilldown" : "Peter Meszaros",
+               "name" : "Peter Meszaros"
+            },
+            {
+               "name" : "Reinier Maliepaard",
+               "drilldown" : "Reinier Maliepaard",
+               "y" : 3
+            },
+            {
+               "name" : "Robbie Hatley",
+               "drilldown" : "Robbie Hatley",
+               "y" : 3
+            },
+            {
+               "name" : "Robert Ransbottom",
+               "drilldown" : "Robert Ransbottom",
+               "y" : 2
+            },
+            {
+               "name" : "Roger Bell_West",
+               "drilldown" : "Roger Bell_West",
+               "y" : 5
+            },
+            {
+               "name" : "Ryan Thompson",
+               "drilldown" : "Ryan Thompson",
+               "y" : 3
+            },
+            {
+               "y" : 2,
+               "name" : "Santiago Leyva",
+               "drilldown" : "Santiago Leyva"
+            },
+            {
+               "drilldown" : "Simon Green",
+               "name" : "Simon Green",
+               "y" : 3
+            },
+            {
+               "y" : 4,
+               "name" : "Thomas Kohler",