- Added solution by Pete Houston.

12 files changed, 645 insertions, 605 deletions

diff --git a/challenge-053/pete-houston/perl/ch-2.pl b/challenge-053/pete-houston/perl/ch-2.pl
new file mode 100644
index 0000000000..6107930877
--- /dev/null
+++ b/challenge-053/pete-houston/perl/ch-2.pl
@@ -0,0 +1,25 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use feature 'say';
+
+my %rules = (
+    a => [qw/e i/],
+    e => [qw/i/],
+    i => [qw/a e o u/],
+    o => [qw/a u/],
+    u => [qw/o e/]
+);
+
+my $n = int shift @ARGV;
+die "1 <= N <= 5 is the restriction.\n" unless $n > 0 && $n < 6;
+
+next_str ($_) for keys %rules;
+
+sub next_str {
+    my $string = shift;
+    return say $string if length $string == $n;
+    for my $c (@{$rules{substr ($string, -1, 1)}}) {
+        next_str ("$string$c");
+    }
+}
diff --git a/stats/pwc-current.json b/stats/pwc-current.json
index 8307d2d2b5..af1a4c72ca 100644
--- a/stats/pwc-current.json
+++ b/stats/pwc-current.json
@@ -1,21 +1,15 @@
 {
-   "subtitle" : {
-      "text" : "[Champions: 7] Last updated at 2020-03-23 15:18:37 GMT"
-   },
-   "title" : {
-      "text" : "Perl Weekly Challenge - 053"
-   },
    "drilldown" : {
       "series" : [
          {
+            "id" : "Dave Cross",
+            "name" : "Dave Cross",
             "data" : [
                [
                   "Perl",
                   2
                ]
-            ],
-            "name" : "Dave Cross",
-            "id" : "Dave Cross"
+            ]
          },
          {
             "data" : [
@@ -32,10 +26,11 @@
                   1
                ]
             ],
-            "name" : "Javier Luque",
-            "id" : "Javier Luque"
+            "id" : "Javier Luque",
+            "name" : "Javier Luque"
          },
          {
+            "id" : "Luca Ferrari",
             "name" : "Luca Ferrari",
             "data" : [
                [
@@ -46,11 +41,21 @@
                   "Blog",
                   2
                ]
-            ],
-            "id" : "Luca Ferrari"
+            ]
+         },
+         {
+            "id" : "Pete Houston",
+            "name" : "Pete Houston",
+            "data" : [
+               [
+                  "Perl",
+                  1
+               ]
+            ]
          },
          {
             "name" : "Roger Bell West",
+            "id" : "Roger Bell West",
             "data" : [
                [
                   "Perl",
@@ -60,68 +65,92 @@
                   "Raku",
                   2
                ]
-            ],
-            "id" : "Roger Bell West"
+            ]
          },
          {
-            "name" : "Simon Proctor",
             "data" : [
                [
                   "Raku",
                   2
                ]
             ],
+            "name" : "Simon Proctor",
             "id" : "Simon Proctor"
          },
          {
+            "id" : "Wanderdoc",
             "name" : "Wanderdoc",
             "data" : [
                [
                   "Perl",
                   2
                ]
-            ],
-            "id" : "Wanderdoc"
+            ]
          },
          {
             "id" : "Yet Ebreo",
+            "name" : "Yet Ebreo",
             "data" : [
                [
                   "Perl",
                   2
                ]
-            ],
-            "name" : "Yet Ebreo"
+            ]
          }
       ]
    },
-   "xAxis" : {
-      "type" : "category"
+   "yAxis" : {
+      "title" : {
+         "text" : "Total Solutions"
+      }
+   },
+   "tooltip" : {
+      "followPointer" : 1,
+      "headerFormat" : "<span style='font-size:11px'>{series.name}</span><br/>",
+      "pointFormat" : "<span style='color:{point.color}'>{point.name}</span>: <b>{point.y:f}</b><br/>"
+   },
+   "title" : {
+      "text" : "Perl Weekly Challenge - 053"
+   },
+   "legend" : {
+      "enabled" : 0
+   },
+   "plotOptions" : {
+      "series" : {
+         "dataLabels" : {
+            "enabled" : 1,
+            "format" : "{point.y}"
+         },
+         "borderWidth" : 0
+      }
    },
    "series" : [
       {
-         "colorByPoint" : 1,
-         "name" : "Perl Weekly Challenge - 053",
          "data" : [
             {
+               "y" : 2,
                "name" : "Dave Cross",
-               "drilldown" : "Dave Cross",
-               "y" : 2
+               "drilldown" : "Dave Cross"
             },
             {
                "y" : 5,
-               "drilldown" : "Javier Luque",
-               "name" : "Javier Luque"
+               "name" : "Javier Luque",
+               "drilldown" : "Javier Luque"
             },
             {
-               "y" : 4,
+               "drilldown" : "Luca Ferrari",
                "name" : "Luca Ferrari",
-               "drilldown" : "Luca Ferrari"
+               "y" : 4
             },
             {
+               "y" : 1,
+               "name" : "Pete Houston",
+               "drilldown" : "Pete Houston"
+            },
+            {
+               "y" : 4,
                "name" : "Roger Bell West",
-               "drilldown" : "Roger Bell West",
-               "y" : 4
+               "drilldown" : "Roger Bell West"
             },
             {
                "y" : 2,
@@ -134,36 +163,22 @@
                "drilldown" : "Wanderdoc"
             },
             {
-               "y" : 2,
+               "name" : "Yet Ebreo",
                "drilldown" : "Yet Ebreo",
-               "name" : "Yet Ebreo"
+               "y" : 2
             }
-         ]
+         ],
+         "colorByPoint" : 1,
+         "name" : "Perl Weekly Challenge - 053"
       }
    ],
-   "plotOptions" : {
-      "series" : {
-         "dataLabels" : {
-            "format" : "{point.y}",
-            "enabled" : 1
-         },
-         "borderWidth" : 0
-      }
+   "xAxis" : {
+      "type" : "category"
+   },
+   "subtitle" : {
+      "text" : "[Champions: 8] Last updated at 2020-03-23 15:57:20 GMT"
    },
    "chart" : {
       "type" : "column"
-   },
-   "legend" : {
-      "enabled" : 0
-   },
-   "yAxis" : {
-      "title" : {
-         "text" : "Total Solutions"
-      }
-   },
-   "tooltip" : {
-      "headerFormat" : "<span style='font-size:11px'>{series.name}</span><br/>",
-      "pointFormat" : "<span style='color:{point.color}'>{point.name}</span>: <b>{point.y:f}</b><br/>",
-      "followPointer" : 1
    }
 }
diff --git a/stats/pwc-language-breakdown-summary.json b/stats/pwc-language-breakdown-summary.json
index 5f48c177d5..c9aa7918e3 100644
--- a/stats/pwc-language-breakdown-summary.json
+++ b/stats/pwc-language-breakdown-summary.json
@@ -5,14 +5,17 @@
          "text" : null
       }
    },
-   "tooltip" : {
-      "pointFormat" : "<b>{point.y:.0f}</b>"
+   "title" : {
+      "text" : "Perl Weekly Challenge Contributions [2019 - 2020]"
    },
    "legend" : {
       "enabled" : "false"
    },
-   "chart" : {
-      "type" : "column"
+   "tooltip" : {
+      "pointFormat" : "<b>{point.y:.0f}</b>"
+   },
+   "subtitle" : {
+      "text" : "Last updated at 2020-03-23 15:57:20 GMT"
    },
    "series" : [
       {
@@ -21,12 +24,12 @@
                "fontSize" : "13px",
                "fontFamily" : "Verdana, sans-serif"
             },
-            "rotation" : -90,
+            "color" : "#FFFFFF",
             "enabled" : "true",
             "align" : "right",
+            "y" : 10,
             "format" : "{point.y:.0f}",
-            "color" : "#FFFFFF",
-            "y" : 10
+            "rotation" : -90
          },
          "data" : [
             [
@@ -35,7 +38,7 @@
             ],
             [
                "Perl",
-               2213
+               2214
             ],
             [
                "Raku",
@@ -54,10 +57,7 @@
       },
       "type" : "category"
    },
-   "title" : {
-      "text" : "Perl Weekly Challenge Contributions [2019 - 2020]"
-   },
-   "subtitle" : {
-      "text" : "Last updated at 2020-03-23 15:18:37 GMT"
+   "chart" : {
+      "type" : "column"
    }
 }
diff --git a/stats/pwc-language-breakdown.json b/stats/pwc-language-breakdown.json
index dcafaefa0a..02c0d6ae38 100644
--- a/stats/pwc-language-breakdown.json
+++ b/stats/pwc-language-breakdown.json
@@ -1,33 +1,12 @@
 {
-   "legend" : {
-      "enabled" : "false"
-   },
-   "plotOptions" : {
-      "series" : {
-         "dataLabels" : {
-            "format" : "{point.y}",
-            "enabled" : 1
-         },
-         "borderWidth" : 0
-      }
-   },
-   "chart" : {
-      "type" : "column"
-   },
    "yAxis" : {
       "title" : {
          "text" : "Total Solutions"
       }
    },
-   "tooltip" : {
-      "followPointer" : "true",
-      "pointFormat" : "<span style=\"color:{point.color}\">Challenge {point.name}</span>: <b>{point.y:f}</b><br/>",
-      "headerFormat" : "<span style=\"font-size:11px\"></span>"
-   },
    "drilldown" : {
       "series" : [
          {
-            "name" : "001",
             "data" : [
                [
                   "Perl",
@@ -42,11 +21,10 @@
                   11
                ]
             ],
+            "name" : "001",
             "id" : "001"
          },
          {
-            "id" : "002",
-            "name" : "002",
             "data" : [
                [
                   "Perl",
@@ -60,10 +38,13 @@
                   "Blog",
                   10
                ]
-            ]
+            ],
+            "name" : "002",
+            "id" : "002"
          },
          {
             "name" : "003",
+            "id" : "003",
             "data" : [
                [
                   "Perl",
@@ -77,11 +58,11 @@
                   "Blog",
                   9
                ]
-            ],
-            "id" : "003"
+            ]
          },
          {
             "id" : "004",
+            "name" : "004",
             "data" : [
                [
                   "Perl",
@@ -95,11 +76,9 @@
                   "Blog",
                   10
                ]
-            ],
-            "name" : "004"
+            ]
          },
          {
-            "name" : "005",
             "data" : [
                [
                   "Perl",
@@ -114,9 +93,12 @@
                   12
                ]
             ],
-            "id" : "005"
+            "id" : "005",
+            "name" : "005"
          },
          {
+            "name" : "006",
+            "id" : "006",
             "data" : [
                [
                   "Perl",
@@ -130,12 +112,11 @@
                   "Blog",
                   7
                ]
-            ],
-            "name" : "006",
-            "id" : "006"
+            ]
          },
          {
             "id" : "007",
+            "name" : "007",
             "data" : [
                [
                   "Perl",
@@ -149,11 +130,11 @@
                   "Blog",
                   10
                ]
-            ],
-            "name" : "007"
+            ]
          },
          {
             "name" : "008",
+            "id" : "008",
             "data" : [
                [
                   "Perl",
@@ -167,10 +148,10 @@
                   "Blog",
                   12
                ]
-            ],
-            "id" : "008"
+            ]
          },
          {
+            "name" : "009",
             "id" : "009",
             "data" : [
                [
@@ -185,11 +166,9 @@
                   "Blog",
                   13
                ]
-            ],
-            "name" : "009"
+            ]
          },
          {
-            "id" : "010",
             "data" : [
                [
                   "Perl",
@@ -204,10 +183,10 @@
                   11
                ]
             ],
-            "name" : "010"
+            "name" : "010",
+            "id" : "010"
          },
          {
-            "name" : "011",
             "data" : [
                [
                   "Perl",
@@ -222,10 +201,10 @@
                   10
                ]
             ],
+            "name" : "011",
             "id" : "011"
          },
          {
-            "name" : "012",
             "data" : [
                [
                   "Perl",
@@ -240,11 +219,12 @@
                   11
                ]
             ],
-            "id" : "012"
+            "id" : "012",
+            "name" : "012"
          },
          {
-            "id" : "013",
             "name" : "013",
+            "id" : "013",
             "data" : [
                [
                   "Perl",
@@ -280,6 +260,7 @@
          },
          {
             "name" : "015",
+            "id" : "015",
             "data" : [
                [
                   "Perl",
@@ -293,11 +274,9 @@
                   "Blog",
                   15
                ]
-            ],
-            "id" : "015"
+            ]
          },
          {
-            "name" : "016",
             "data" : [
                [
                   "Perl",
@@ -312,11 +291,10 @@
                   12
                ]
             ],
+            "name" : "016",
             "id" : "016"
          },
          {
-            "id" : "017",
-            "name" : "017",
             "data" : [
                [
                   "Perl",
@@ -330,10 +308,11 @@
                   "Blog",
                   12
                ]
-            ]
+            ],
+            "id" : "017",
+            "name" : "017"
          },
          {
-            "id" : "018",
             "data" : [
                [
                   "Perl",
@@ -348,9 +327,12 @@
                   14
                ]
             ],
+            "id" : "018",
             "name" : "018"
          },
          {
+            "name" : "019",
+            "id" : "019",
             "data" : [
                [
                   "Perl",
@@ -364,13 +346,9 @@
                   "Blog",
                   13
                ]
-            ],
-            "name" : "019",
-            "id" : "019"
+            ]
          },
          {
-            "id" : "020",
-            "name" : "020",
             "data" : [
                [
                   "Perl",
@@ -384,10 +362,11 @@
                   "Blog",
                   13
                ]
-            ]
+            ],
+            "id" : "020",
+            "name" : "020"
          },
          {
-            "id" : "021",
             "data" : [
                [
                   "Perl",
@@ -402,9 +381,11 @@
                   10
                ]
             ],
+            "id" : "021",
             "name" : "021"
          },
          {
+            "name" : "022",
             "id" : "022",
             "data" : [
                [
@@ -419,12 +400,9 @@
                   "Blog",
                   10
                ]
-            ],
-            "name" : "022"
+            ]
          },
          {
-            "id" : "023",
-            "name" : "023",
             "data" : [
                [
                   "Perl",
@@ -438,9 +416,12 @@
                   "Blog",
                   12
                ]
-            ]
+            ],
+            "name" : "023",
+            "id" : "023"
          },
          {
+            "id" : "024",
             "name" : "024",
             "data" : [
                [
@@ -455,11 +436,11 @@
                   "Blog",
                   11
                ]
-            ],
-            "id" : "024"
+            ]
          },
          {
             "id" : "025",
+            "name" : "025",
             "data" : [
                [
                   "Perl",
@@ -473,8 +454,7 @@
                   "Blog",
                   12
                ]
-            ],
-            "name" : "025"
+            ]
          },
          {
             "data" : [
@@ -495,7 +475,6 @@
             "id" : "026"
          },
          {
-            "id" : "027",
             "data" : [
                [
                   "Perl",
@@ -510,6 +489,7 @@
                   9
                ]
             ],
+            "id" : "027",
             "name" : "027"
          },
          {
@@ -531,7 +511,6 @@
             ]
          },
          {
-            "id" : "029",
             "data" : [
                [
                   "Perl",
@@ -546,9 +525,11 @@
                   12
                ]
             ],
+            "id" : "029",
             "name" : "029"
          },
          {
+            "name" : "030",
             "id" : "030",
             "data" : [
                [
@@ -563,11 +544,9 @@
                   "Blog",
                   10
                ]
-            ],
-            "name" : "030"
+            ]
          },
          {
-            "id" : "031",
             "data" : [
                [
                   "Perl",
@@ -582,11 +561,10 @@
                   9
                ]
             ],
-            "name" : "031"
+            "name" : "031",
+            "id" : "031"
          },
          {
-            "id" : "032",
-            "name" : "032",
             "data" : [
                [
                   "Perl",
@@ -600,10 +578,11 @@
                   "Blog",
                   10
                ]
-            ]
+            ],
+            "name" : "032",
+            "id" : "032"
          },
          {
-            "name" : "033",
             "data" : [
                [
                   "Perl",
@@ -618,11 +597,12 @@
                   10
                ]
             ],
+            "name" : "033",
             "id" : "033"
          },
          {
-            "id" : "034",
             "name" : "034",
+            "id" : "034",
             "data" : [
                [
                   "Perl",
@@ -639,8 +619,8 @@
             ]
          },
          {
-            "id" : "035",
             "name" : "035",
+            "id" : "035",
             "data" : [
                [
                   "Perl",
@@ -671,12 +651,10 @@
                   10
                ]
             ],
-            "name" : "036",
-            "id" : "036"
+            "id" : "036",
+            "name" : "036"
          },
          {
-            "id" : "037",
-            "name" : "037",
             "data" : [
                [
                   "Perl",
@@ -690,10 +668,11 @@
                   "Blog",
                   9
                ]
-            ]
+            ],
+            "id" : "037",
+            "name" : "037"
          },
          {
-            "id" : "038",
             "data" : [
                [
                   "Perl",
@@ -708,9 +687,12 @@
                   12
                ]
             ],
-            "name" : "038"
+            "name" : "038",
+            "id" : "038"
          },
          {
+            "id" : "039",
+            "name" : "039",
             "data" : [
                [
                   "Perl",
@@ -724,12 +706,11 @@
                   "Blog",
                   12
                ]
-            ],
-            "name" : "039",
-            "id" : "039"
+            ]
          },
          {
             "name" : "040",
+            "id" : "040",
             "data" : [
                [
                   "Perl",
@@ -743,11 +724,9 @@
                   "Blog",
                   9
                ]
-            ],
-            "id" : "040"
+            ]
          },
          {
-            "id" : "041",
             "data" : [
                [
                   "Perl",
@@ -762,11 +741,10 @@
                   8
                ]
             ],
-            "name" : "041"
+            "name" : "041",
+            "id" : "041"
          },
          {
-            "id" : "042",
-            "name" : "042",
             "data" : [
                [
                   "Perl",
@@ -780,10 +758,11 @@
                   "Blog",
                   11
                ]
-            ]
+            ],
+            "name" : "042",
+            "id" : "042"
          },
          {
-            "id" : "043",
             "data" : [
                [
                   "Perl",
@@ -798,11 +777,10 @@
                   10
                ]
             ],
-            "name" : "043"
+            "name" : "043",
+            "id" : "043"
          },
          {
-            "id" : "044",
-            "name" : "044",
             "data" : [
                [
                   "Perl",
@@ -816,7 +794,9 @@
                   "Blog",
                   10
                ]
-            ]
+            ],
+            "id" : "044",
+            "name" : "044"
          },
          {
             "data" : [
@@ -837,8 +817,6 @@
             "id" : "045"
          },
          {
-            "id" : "046",
-            "name" : "046",
             "data" : [
                [
                   "Perl",
@@ -852,9 +830,13 @@
                   "Blog",
                   10
                ]
-            ]
+            ],
+            "id" : "046",
+            "name" : "046"
          },
          {
+            "name" : "047",
+            "id" : "047",
             "data" : [
                [
                   "Perl",
@@ -868,13 +850,11 @@
                   "Blog",
                   10
                ]
-            ],
-            "name" : "047",
-            "id" : "047"
+            ]
          },
          {
-            "id" : "048",
             "name" : "048",
+            "id" : "048",
             "data" : [
                [
                   "Perl",
@@ -892,6 +872,7 @@
          },
          {
             "id" : "049",
+            "name" : "049",
             "data" : [
                [
                   "Perl",
@@ -905,12 +886,9 @@
                   "Blog",
                   12
                ]
-            ],
-            "name" : "049"
+            ]
          },
          {
-            "id" : "050",
-            "name" : "050",
             "data" : [
                [
                   "Perl",
@@ -924,11 +902,11 @@
                   "Blog",
                   11
                ]
-            ]
+            ],
+            "id" : "050",
+            "name" : "050"
          },
          {
-            "id" : "051",
-            "name" : "051",
             "data" : [
                [
                   "Perl",
@@ -942,7 +920,9 @@
                   "Blog",
                   10
                ]
-            ]
+            ],
+            "name" : "051",
+            "id" : "051"
          },
          {
             "id" : "052",
@@ -963,11 +943,10 @@
             ]
          },
          {
-            "name" : "053",
             "data" : [
                [
                   "Perl",
-                  10
+                  11
                ],
                [
                   "Raku",
@@ -978,34 +957,55 @@
                   3
                ]
             ],
-            "id" : "053"
+            "id" : "053",
+            "name" : "053"
          }
       ]
    },
+   "legend" : {
+      "enabled" : "false"
+   },
    "title" : {
       "text" : "Perl Weekly Challenge Language"
    },
+   "tooltip" : {
+      "followPointer" : "true",
+      "pointFormat" : "<span style=\"color:{point.color}\">Challenge {point.name}</span>: <b>{point.y:f}</b><br/>",
+      "headerFormat" : "<span style=\"font-size:11px\"></span>"
+   },
    "subtitle" : {
-      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2020-03-23 15:18:37 GMT"
+      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2020-03-23 15:57:20 GMT"
+   },
+   "xAxis" : {
+      "type" : "category"
+   },
+   "plotOptions" : {
+      "series" : {
+         "borderWidth" : 0,
+         "dataLabels" : {
+            "format" : "{point.y}",
+            "enabled" : 1
+         }
+      }
    },
    "series" : [
       {
          "colorByPoint" : "true",
          "data" : [
             {
+               "y" : 140,
                "name" : "#001",
-               "drilldown" : "001",
-               "y" : 140
+               "drilldown" : "001"
             },
             {
                "y" : 109,
-               "drilldown" : "002",
-               "name" : "#002"
+               "name" : "#002",
+               "drilldown" : "002"
             },
             {
                "y" : 71,
-               "drilldown" : "003",
-               "name" : "#003"
+               "name" : "#003",
+               "drilldown" : "003"
             },
             {
                "y" : 91,
@@ -1014,8 +1014,8 @@
             },
             {
                "y" : 71,
-               "drilldown" : "005",
-               "name" : "#005"
+               "name" : "#005",
+               "drilldown" : "005"
             },
             {
                "y" : 52,
@@ -1023,14 +1023,14 @@
                "drilldown" : "006"
             },
             {
+               "y" : 58,
                "drilldown" : "007",
-               "name" : "#007",
-               "y" : 58
+               "name" : "#007"
             },
             {
-               "name" : "#008",
+               "y" : 70,
                "drilldown" : "008",
-               "y" : 70
+               "name" : "#008"
             },
             {
                "drilldown" : "009",
@@ -1038,14 +1038,14 @@
                "y" : 68
             },
             {
+               "y" : 60,
                "name" : "#010",
-               "drilldown" : "010",
-               "y" : 60
+               "drilldown" : "010"
             },
             {
-               "y" : 79,
                "drilldown" : "011",
-               "name" : "#011"
+               "name" : "#011",
+               "y" : 79
             },
             {
                "drilldown" : "012",
@@ -1053,19 +1053,19 @@
                "y" : 83
             },
             {
-               "name" : "#013",
+               "y" : 76,
                "drilldown" : "013",
-               "y" : 76
+               "name" : "#013"
             },
             {
-               "name" : "#014",
                "drilldown" : "014",
+               "name" : "#014",
                "y" : 96
             },
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+               "y" : 93,
                "name" : "#015",
-               "drilldown" : "015",
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+               "drilldown" : "015"
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@@ -1073,29 +1073,29 @@
                "drilldown" : "016"
             },
             {
-               "y" : 79,
                "drilldown" : "017",
-               "name" : "#017"
+               "name" : "#017",
+               "y" : 79
             },
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+               "y" : 76,
                "name" : "#018",
-               "drilldown" : "018",
-               "y" : 76
+               "drilldown" : "018"
             },
             {
                "y" : 97,
-               "drilldown" : "019",
-               "name" : "#019"
+               "name" : "#019",
+               "drilldown" : "019"
             },
             {
-               "y" : 95,
+               "name" : "#020",
                "drilldown" : "020",
-               "na