- Added solutions by Laurent Rosenfeld.

19 files changed, 1414 insertions, 1316 deletions

diff --git a/challenge-143/laurent-rosenfeld/blog.txt b/challenge-143/laurent-rosenfeld/blog.txt
new file mode 100644
index 0000000000..3b1d505950
--- /dev/null
+++ b/challenge-143/laurent-rosenfeld/blog.txt
@@ -0,0 +1 @@
+http://blogs.perl.org/users/laurent_r/2021/12/post.html
diff --git a/challenge-143/laurent-rosenfeld/perl/ch-1.pl b/challenge-143/laurent-rosenfeld/perl/ch-1.pl
new file mode 100644
index 0000000000..bb8edda515
--- /dev/null
+++ b/challenge-143/laurent-rosenfeld/perl/ch-1.pl
@@ -0,0 +1,13 @@
+use strict;
+use warnings;
+use feature "say";
+
+sub calc {
+    my $expr = shift;
+    return "Not a valid arithmetic expression" unless
+        $expr =~ /^[-\d\s+*()]+$/;
+    return eval $expr;
+}
+for my $test ("10 + 20 - 5", "(10 + 20 - 5) * 2", "7 + a", "6 * 7") {
+    say calc $test;
+}
diff --git a/challenge-143/laurent-rosenfeld/perl/ch-2.pl b/challenge-143/laurent-rosenfeld/perl/ch-2.pl
new file mode 100644
index 0000000000..4c0d53cc74
--- /dev/null
+++ b/challenge-143/laurent-rosenfeld/perl/ch-2.pl
@@ -0,0 +1,33 @@
+use strict;
+use warnings;
+use feature "say";
+
+sub cross {
+    my @nums = @_;
+    my @num_pairs;
+    for my $i (@nums) {
+        for my $j (@nums) {
+            next if $j > $i; # filter out duplicates such as [12, 3] and [3, 12]
+            push @num_pairs, [$i, $j];
+        }
+    }
+    return @num_pairs;
+}
+
+sub stealthy_nums  {
+    my $n = shift;
+    my @divisors = grep {$n % $_ == 0} 1..$n;
+    my @div_pairs = grep { $_->[0] * $_->[1] == $n } cross @divisors;
+    for my $c (@div_pairs) {
+        for my $d (@div_pairs) {
+            return "@$c and @$d" if abs($c->[0] + $c->[1] - $d->[0] - $d->[1]) == 1;
+        }
+    }
+    return 0;
+}
+
+for my $test (qw <36 12 6>) {
+    my $result = stealthy_nums $test;
+    say "$test \t",
+    $result ? "1 -> $result" : 0;
+}
diff --git a/challenge-143/laurent-rosenfeld/raku/ch-1.raku b/challenge-143/laurent-rosenfeld/raku/ch-1.raku
new file mode 100644
index 0000000000..023b6d07d7
--- /dev/null
+++ b/challenge-143/laurent-rosenfeld/raku/ch-1.raku
@@ -0,0 +1,11 @@
+use v6;
+use MONKEY-SEE-NO-EVAL;
+
+sub calc (Str $expr) {
+    return "Not a valid arithmetic expression" unless
+        $expr ~~ /^<[-\d \s +*()]>+$/;
+    return EVAL $expr;
+}
+for "10 + 20 - 5", "(10 + 20 - 5) * 2", "7 + a", "6 * 7" -> $test {
+    say calc $test;
+}
diff --git a/challenge-143/laurent-rosenfeld/raku/ch-2.raku b/challenge-143/laurent-rosenfeld/raku/ch-2.raku
new file mode 100644
index 0000000000..8be44009c9
--- /dev/null
+++ b/challenge-143/laurent-rosenfeld/raku/ch-2.raku
@@ -0,0 +1,17 @@
+use v6;
+
+sub stealthy-nums (UInt $n) {
+    my @divisors = grep {$n %% $_}, 1..$n;
+    my @div-pairs = grep { $_[0] * $_[1] == $n }, (@divisors X @divisors);
+    # say @div-pairs;
+    for @div-pairs.combinations: 2 -> $c {
+        return $c if $c[0][0] + $c[0][1] - $c[1][0] - $c[1][1] == any(1, -1)
+    }
+    return False
+}
+
+for <36 12 6> -> $test {
+    my $result = stealthy-nums $test;
+    say "$test \t",
+    $result ?? "1 -> $result" !! 0;
+}
diff --git a/stats/pwc-current.json b/stats/pwc-current.json
index a01a3f87f8..eec2b4e797 100644
--- a/stats/pwc-current.json
+++ b/stats/pwc-current.json
@@ -1,9 +1,4 @@
 {
-   "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
-   },
    "series" : [
       {
          "name" : "The Weekly Challenge - 143",
@@ -20,96 +15,85 @@
                "y" : 3
             },
             {
-               "drilldown" : "E. Choroba",
                "name" : "E. Choroba",
+               "drilldown" : "E. Choroba",
                "y" : 2
             },
             {
+               "y" : 6,
                "drilldown" : "Flavio Poletti",
-               "name" : "Flavio Poletti",
-               "y" : 6
+               "name" : "Flavio Poletti"
+            },
+            {
+               "name" : "Laurent Rosenfeld",
+               "drilldown" : "Laurent Rosenfeld",
+               "y" : 5
             },
             {
-               "y" : 5,
                "name" : "Luca Ferrari",
+               "y" : 5,
                "drilldown" : "Luca Ferrari"
             },
             {
                "drilldown" : "Mohammad S Anwar",
-               "name" : "Mohammad S Anwar",
-               "y" : 1
+               "y" : 1,
+               "name" : "Mohammad S Anwar"
             },
             {
-               "y" : 1,
                "drilldown" : "Olivier Delouya",
+               "y" : 1,
                "name" : "Olivier Delouya"
             },
             {
-               "y" : 2,
                "name" : "Paulo Custodio",
+               "y" : 2,
                "drilldown" : "Paulo Custodio"
             },
             {
+               "drilldown" : "Peter Campbell Smith",
                "y" : 3,
-               "name" : "Peter Campbell Smith",
-               "drilldown" : "Peter Campbell Smith"
+               "name" : "Peter Campbell Smith"
             },
             {
-               "y" : 2,
                "name" : "Robert DiCicco",
+               "y" : 2,
                "drilldown" : "Robert DiCicco"
             },
             {
-               "y" : 4,
                "drilldown" : "Roger Bell_West",
+               "y" : 4,
                "name" : "Roger Bell_West"
             },
             {
-               "drilldown" : "Ulrich Rieke",
                "name" : "Ulrich Rieke",
+               "drilldown" : "Ulrich Rieke",
                "y" : 2
             },
             {
+               "drilldown" : "W. Luis Mochan",
                "y" : 3,
-               "name" : "W. Luis Mochan",
-               "drilldown" : "W. Luis Mochan"
+               "name" : "W. Luis Mochan"
             }
          ]
       }
    ],
-   "chart" : {
-      "type" : "column"
-   },
-   "xAxis" : {
-      "type" : "category"
-   },
-   "plotOptions" : {
-      "series" : {
-         "borderWidth" : 0,
-         "dataLabels" : {
-            "enabled" : 1,
-            "format" : "{point.y}"
-         }
-      }
-   },
-   "yAxis" : {
-      "title" : {
-         "text" : "Total Solutions"
-      }
+   "title" : {
+      "text" : "The Weekly Challenge - 143"
    },
    "drilldown" : {
       "series" : [
          {
-            "id" : "Alexander Pankoff",
+            "name" : "Alexander Pankoff",
             "data" : [
                [
                   "Perl",
                   2
                ]
             ],
-            "name" : "Alexander Pankoff"
+            "id" : "Alexander Pankoff"
          },
          {
+            "id" : "Dave Jacoby",
             "data" : [
                [
                   "Perl",
@@ -120,8 +104,7 @@
                   1
                ]
             ],
-            "name" : "Dave Jacoby",
-            "id" : "Dave Jacoby"
+            "name" : "Dave Jacoby"
          },
          {
             "data" : [
@@ -130,8 +113,8 @@
                   2
                ]
             ],
-            "name" : "E. Choroba",
-            "id" : "E. Choroba"
+            "id" : "E. Choroba",
+            "name" : "E. Choroba"
          },
          {
             "data" : [
@@ -148,11 +131,30 @@
                   2
                ]
             ],
-            "name" : "Flavio Poletti",
-            "id" : "Flavio Poletti"
+            "id" : "Flavio Poletti",
+            "name" : "Flavio Poletti"
+         },
+         {
+            "name" : "Laurent Rosenfeld",
+            "id" : "Laurent Rosenfeld",
+            "data" : [
+               [
+                  "Perl",
+                  2
+               ],
+               [
+                  "Raku",
+                  2
+               ],
+               [
+                  "Blog",
+                  1
+               ]
+            ]
          },
          {
             "name" : "Luca Ferrari",
+            "id" : "Luca Ferrari",
             "data" : [
                [
                   "Raku",
@@ -162,8 +164,7 @@
                   "Blog",
                   3
                ]
-            ],
-            "id" : "Luca Ferrari"
+            ]
          },
          {
             "name" : "Mohammad S Anwar",
@@ -176,27 +177,27 @@
             "id" : "Mohammad S Anwar"
          },
          {
-            "id" : "Olivier Delouya",
-            "name" : "Olivier Delouya",
             "data" : [
                [
                   "Perl",
                   1
                ]
-            ]
+            ],
+            "id" : "Olivier Delouya",
+            "name" : "Olivier Delouya"
          },
          {
+            "id" : "Paulo Custodio",
             "data" : [
                [
                   "Perl",
                   2
                ]
             ],
-            "name" : "Paulo Custodio",
-            "id" : "Paulo Custodio"
+            "name" : "Paulo Custodio"
          },
          {
-            "id" : "Peter Campbell Smith",
+            "name" : "Peter Campbell Smith",
             "data" : [
                [
                   "Perl",
@@ -207,20 +208,20 @@
                   1
                ]
             ],
-            "name" : "Peter Campbell Smith"
+            "id" : "Peter Campbell Smith"
          },
          {
-            "id" : "Robert DiCicco",
-            "name" : "Robert DiCicco",
             "data" : [
                [
                   "Perl",
                   2
                ]
-            ]
+            ],
+            "id" : "Robert DiCicco",
+            "name" : "Robert DiCicco"
          },
          {
-            "id" : "Roger Bell_West",
+            "name" : "Roger Bell_West",
             "data" : [
                [
                   "Perl",
@@ -231,9 +232,10 @@
                   2
                ]
             ],
-            "name" : "Roger Bell_West"
+            "id" : "Roger Bell_West"
          },
          {
+            "name" : "Ulrich Rieke",
             "id" : "Ulrich Rieke",
             "data" : [
                [
@@ -244,11 +246,10 @@
                   "Raku",
                   1
                ]
-            ],
-            "name" : "Ulrich Rieke"
+            ]
          },
          {
-            "name" : "W. Luis Mochan",
+            "id" : "W. Luis Mochan",
             "data" : [
                [
                   "Perl",
@@ -259,17 +260,39 @@
                   1
                ]
             ],
-            "id" : "W. Luis Mochan"
+            "name" : "W. Luis Mochan"
          }
       ]
    },
-   "subtitle" : {
-      "text" : "[Champions: 13] Last updated at 2021-12-15 10:22:00 GMT"
+   "chart" : {
+      "type" : "column"
+   },
+   "xAxis" : {
+      "type" : "category"
+   },
+   "plotOptions" : {
+      "series" : {
+         "dataLabels" : {
+            "enabled" : 1,
+            "format" : "{point.y}"
+         },
+         "borderWidth" : 0
+      }
+   },
+   "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/>"
    },
    "legend" : {
       "enabled" : 0
    },
-   "title" : {
-      "text" : "The Weekly Challenge - 143"
+   "subtitle" : {
+      "text" : "[Champions: 14] Last updated at 2021-12-15 11:52:47 GMT"
+   },
+   "yAxis" : {
+      "title" : {
+         "text" : "Total Solutions"
+      }
    }
 }
diff --git a/stats/pwc-language-breakdown-summary.json b/stats/pwc-language-breakdown-summary.json
index 65964220b9..d58b8de874 100644
--- a/stats/pwc-language-breakdown-summary.json
+++ b/stats/pwc-language-breakdown-summary.json
@@ -1,53 +1,44 @@
 {
-   "yAxis" : {
-      "min" : 0,
-      "title" : {
-         "text" : null
-      }
-   },
-   "subtitle" : {
-      "text" : "Last updated at 2021-12-15 10:22:00 GMT"
-   },
-   "legend" : {
-      "enabled" : "false"
-   },
    "title" : {
       "text" : "The Weekly Challenge Contributions [2019 - 2021]"
    },
    "series" : [
       {
-         "dataLabels" : {
-            "rotation" : -90,
-            "enabled" : "true",
-            "y" : 10,
-            "style" : {
-               "fontFamily" : "Verdana, sans-serif",
-               "fontSize" : "13px"
-            },
-            "color" : "#FFFFFF",
-            "format" : "{point.y:.0f}",
-            "align" : "right"
-         },
-         "name" : "Contributions",
          "data" : [
             [
                "Blog",
-               2097
+               2098
             ],
             [
                "Perl",
-               6875
+               6877
             ],
             [
                "Raku",
-               4156
+               4158
             ]
-         ]
+         ],
+         "dataLabels" : {
+            "enabled" : "true",
+            "y" : 10,
+            "style" : {
+               "fontFamily" : "Verdana, sans-serif",
+               "fontSize" : "13px"
+            },
+            "rotation" : -90,
+            "align" : "right",
+            "format" : "{point.y:.0f}",
+            "color" : "#FFFFFF"
+         },
+         "name" : "Contributions"
       }
    ],
    "tooltip" : {
       "pointFormat" : "<b>{point.y:.0f}</b>"
    },
+   "legend" : {
+      "enabled" : "false"
+   },
    "xAxis" : {
       "type" : "category",
       "labels" : {
@@ -59,5 +50,14 @@
    },
    "chart" : {
       "type" : "column"
+   },
+   "yAxis" : {
+      "title" : {
+         "text" : null
+      },
+      "min" : 0
+   },
+   "subtitle" : {
+      "text" : "Last updated at 2021-12-15 11:52:47 GMT"
    }
 }
diff --git a/stats/pwc-language-breakdown.json b/stats/pwc-language-breakdown.json
index 81c0f89dfd..ea7ab624f2 100644
--- a/stats/pwc-language-breakdown.json
+++ b/stats/pwc-language-breakdown.json
@@ -2,7 +2,6 @@
    "drilldown" : {
       "series" : [
          {
-            "name" : "001",
             "data" : [
                [
                   "Perl",
@@ -17,7 +16,8 @@
                   11
                ]
             ],
-            "id" : "001"
+            "id" : "001",
+            "name" : "001"
          },
          {
             "id" : "002",
@@ -38,8 +38,8 @@
             "name" : "002"
          },
          {
-            "id" : "003",
             "name" : "003",
+            "id" : "003",
             "data" : [
                [
                   "Perl",
@@ -56,7 +56,7 @@
             ]
          },
          {
-            "name" : "004",
+            "id" : "004",
             "data" : [
                [
                   "Perl",
@@ -71,7 +71,7 @@
                   10
                ]
             ],
-            "id" : "004"
+            "name" : "004"
          },
          {
             "id" : "005",
@@ -92,6 +92,7 @@
             "name" : "005"
          },
          {
+            "name" : "006",
             "id" : "006",
             "data" : [
                [
@@ -106,11 +107,10 @@
                   "Blog",
                   7
                ]
-            ],
-            "name" : "006"
+            ]
          },
          {
-            "id" : "007",
+            "name" : "007",
             "data" : [
                [
                   "Perl",
@@ -125,9 +125,10 @@
                   10
                ]
             ],
-            "name" : "007"
+            "id" : "007"
          },
          {
+            "name" : "008",
             "id" : "008",
             "data" : [
                [
@@ -142,11 +143,10 @@
                   "Blog",
                   12
                ]
-            ],
-            "name" : "008"
+            ]
          },
          {
-            "name" : "009",
+            "id" : "009",
             "data" : [
                [
                   "Perl",
@@ -161,7 +161,7 @@
                   13
                ]
             ],
-            "id" : "009"
+            "name" : "009"
          },
          {
             "data" : [
@@ -178,11 +178,10 @@
                   11
                ]
             ],
-            "name" : "010",
-            "id" : "010"
+            "id" : "010",
+            "name" : "010"
          },
          {
-            "name" : "011",
             "data" : [
                [
                   "Perl",
@@ -197,9 +196,12 @@
                   10
                ]
             ],
-            "id" : "011"
+            "id" : "011",
+            "name" : "011"
          },
          {
+            "name" : "012",
+            "id" : "012",
             "data" : [
                [
                   "Perl",
@@ -213,9 +215,7 @@
                   "Blog",
                   11
                ]
-            ],
-            "name" : "012",
-            "id" : "012"
+            ]
          },
          {
             "data" : [
@@ -232,8 +232,8 @@
                   13
                ]
             ],
-            "name" : "013",
-            "id" : "013"
+            "id" : "013",
+            "name" : "013"
          },
          {
             "data" : [
@@ -250,11 +250,10 @@
                   15
                ]
             ],
-            "name" : "014",
-            "id" : "014"
+            "id" : "014",
+            "name" : "014"
          },
          {
-            "id" : "015",
             "name" : "015",
             "data" : [
                [
@@ -269,9 +268,11 @@
                   "Blog",
                   15
                ]
-            ]
+            ],
+            "id" : "015"
          },
          {
+            "name" : "016",
             "data" : [
                [
                   "Perl",
@@ -286,11 +287,10 @@
                   12
                ]
             ],
-            "name" : "016",
             "id" : "016"
          },
          {
-            "name" : "017",
+            "id" : "017",
             "data" : [
                [
                   "Perl",
@@ -305,11 +305,11 @@
                   12
                ]
             ],
-            "id" : "017"
+            "name" : "017"
          },
          {
-            "id" : "018",
             "name" : "018",
+            "id" : "018",
             "data" : [
                [
                   "Perl",
@@ -340,11 +340,11 @@
                   13
                ]
             ],
-            "name" : "019",
-            "id" : "019"
+            "id" : "019",
+            "name" : "019"
          },
          {
-            "id" : "020",
+            "name" : "020",
             "data" : [
                [
                   "Perl",
@@ -359,11 +359,10 @@
                   13
                ]
             ],
-            "name" : "020"
+            "id" : "020"
          },
          {
             "id" : "021",
-            "name" : "021",
             "data" : [
                [
                   "Perl",
@@ -377,11 +376,11 @@
                   "Blog",
                   10
                ]
-            ]
+            ],
+            "name" : "021"
          },
          {
             "id" : "022",
-            "name" : "022",
             "data" : [
                [
                   "Perl",
@@ -395,9 +394,11 @@
                   "Blog",
                   10
                ]
-            ]
+            ],
+            "name" : "022"
          },
          {
+            "name" : "023",
             "id" : "023",
             "data" : [
                [
@@ -412,8 +413,7 @@
                   "Blog",
                   12
                ]
-            ],
-            "name" : "023"
+            ]
          },
          {
             "data" : [
@@ -430,8 +430,8 @@
                   11
                ]
             ],
-            "name" : "024",
-            "id" : "024"
+            "id" : "024",
+            "name" : "024"
          },
          {
             "name" : "025",
@@ -452,7 +452,6 @@
             "id" : "025"
          },
          {
-            "id" : "026",
             "data" : [
                [
                   "Perl",
@@ -467,6 +466,7 @@
                   10
                ]
             ],
+            "id" : "026",
             "name" : "026"
          },
          {
@@ -488,7 +488,6 @@
             "id" : "027"
          },
          {
-            "name" : "028",
             "data" : [
                [
                   "Perl",
@@ -503,9 +502,11 @@
                   9
                ]
             ],
-            "id" : "028"
+            "id" : "028",
+            "name" : "028"
          },
          {
+            "id" : "029",
             "data" : [
                [
                   "Perl",
@@ -520,11 +521,9 @@
                   12
                ]
             ],
-            "name" : "029",
-            "id" : "029"
+            "name" : "029"
          },
          {
-            "id" : "030",
             "data" : [
                [
                   "Perl",
@@ -539,10 +538,10 @@
                   10
                ]
             ],
+            "id" : "030",
             "name" : "030"
          },
          {
-            "id" : "031",
             "name" : "031",
             "data" : [
                [
@@ -557,11 +556,12 @@
                   "Blog",
                   9
                ]
-            ]
+            ],
+            "id" : "031"
          },
          {
-            "id" : "032",
             "name" : "032",
+            "id" : "032",
             "data" : [
                [
                   "Perl",
@@ -579,6 +579,7 @@
          },
          {
             "name" : "033",
+            "id" : "033",
             "data" : [
                [
                   "Perl",
@@ -592,12 +593,10 @@
                   "Blog",
                   10
                ]
-            ],
-            "id" : "033"
+            ]
          },
          {
             "id" : "034",
-            "name" : "034",
             "data" : [
                [
                   "Perl",
@@ -611,7 +610,8 @@
                   "Blog",
                   11
                ]
-            ]
+            ],
+            "name" : "034"
          },
          {
             "name" : "035",
@@ -632,8 +632,6 @@
             "id" : "035"
          },
          {
-            "id" : "036",
-            "name" : "036",
             "data" : [
                [
                   "Perl",
@@ -647,10 +645,12 @@
                   "Blog",
                   11
                ]
-            ]
+            ],
+            "id" : "036",
+            "name" : "036"
          },
          {
-            "name" : "037",
+            "id" : "037",
             "data" : [
                [
                   "Perl",
@@ -665,11 +665,9 @@
                   9
                ]
             ],
-            "id" : "037"
+            "name" : "037"
          },
          {
-            "id" : "038",
-            "name" : "038",
             "data" : [
                [
                   "Perl",
@@ -683,9 +681,12 @@
                   "Blog",
                   12
                ]
-            ]
+            ],
+            "id" : "038",
+            "name" : "038"
          },
          {
+            "name" : "039",
             "id" : "039",
             "data" : [
                [
@@ -700,11 +701,10 @@
                   "Blog",
                   12
                ]
-            ],
-            "name" : "039"
+            ]
          },
          {
-            "id" : "040",
+            "name" : "040",
             "data" : [
                [
                   "Perl",
@@ -719,11 +719,9 @@
                   10
                ]
             ],
-            "name" : "040"
+            "id" : "040"
          },
          {
-            "id" : "041",
-            "name" : "041",
             "data" : [
                [
                   "Perl",
@@ -737,7 +735,9 @@
                   "Blog",
                   9
                ]
-            ]
+            ],
+            "id" : "041",
+            "name" : "041"
          },
          {
             "name" : "042",
@@ -758,8 +758,6 @@
             "id" : "042"
          },
          {
-            "id" : "043",
-            "name" : "043",
             "data" : [
                [
                   "Perl",
@@ -773,11 +771,13 @@
                   "Blog",
                   11
                ]
-            ]
+            ],
+            "id" : "043",
+            "name" : "043"
          },
          {
-            "id" : "044",
             "name" : "044",
+            "id" : "044",
             "data" : [
                [
                   "Perl",
@@ -794,6 +794,7 @@
             ]
          },
          {
+            "name" : "045",
             "data" : [
                [
                   "Perl",
@@ -808,10 +809,10 @@
                   11
                ]
             ],
-            "name" : "045",
             "id" : "045"
          },
          {
+            "name" : "046",
             "data" : [
                [
                   "Perl",
@@ -826,11 +827,10 @@
                   10
                ]
             ],
-            "name" : "046",
             "id" : "046"
          },
          {
-            "id" : "047",
+            "name" : "047",
             "data" : [
                [
                   "Perl",
@@ -845,10 +845,9 @@
                   10
                ]
             ],
-            "name" : "047"
+            "id" : "047"