- Added solutions by Fabio Valeri.

25 files changed, 214 insertions, 31 deletions

diff --git a/challenge-331/fabio-valeri/perl/ch-1.pl b/challenge-331/fabio-valeri/perl/ch-1.pl
new file mode 100644
index 0000000000..74e5680134
--- /dev/null
+++ b/challenge-331/fabio-valeri/perl/ch-1.pl
@@ -0,0 +1,57 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+# Task 1: Last Word
+# Submitted by: Mohammad Sajid Anwar
+#
+# You are given a string.
+# Write a script to find the length of last word in the given string.
+#
+# Example 1
+# Input: $str = "The Weekly Challenge"
+# Output: 9
+#
+# Example 2
+# Input: $str = "   Hello   World    "
+# Output: 5
+#
+# Example 3
+# Input: $str = "Let's begin the fun"
+# Output: 3
+
+
+# Function to count the number of letters of the last word
+sub last_word {
+    my $input = shift;
+
+    # Read last word considering empty spaces
+    $input =~ /(\S+)\s*$/;
+    # compute length
+    return length($1);
+
+}
+
+# Test cases
+my @test_strings = (
+                     "The Weekly Challenge"
+                    , "Hello   World    "
+                    , "Let's begin the fun"
+);
+
+# Test the function with all test cases
+say "Testing last_word function:\n";
+
+foreach my $test (@test_strings) {
+    my $result = last_word($test);
+    printf "Input:  %-25s => Output: %s\n", "\"$test\"", "\"$result\"";
+}
+
+# Also allow command line testing
+if (@ARGV) {
+    say "\nCommand line input:";
+    my $result = last_word($ARGV[0]);
+    say "Input:  \"$ARGV[0]\" => Output: \"$result\"";
+  }
diff --git a/challenge-331/fabio-valeri/perl/ch-2.pl b/challenge-331/fabio-valeri/perl/ch-2.pl
new file mode 100644
index 0000000000..e7d389f33b
--- /dev/null
+++ b/challenge-331/fabio-valeri/perl/ch-2.pl
@@ -0,0 +1,111 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+
+# Task 2: Buddy Strings
+# Submitted by: Mohammad Sajid Anwar
+#
+# You are given two strings, source and target.
+# Write a script to find out if the given strings are Buddy Strings.
+# If swapping of a letter in one string make them same as the other then they are `Buddy Strings`.
+#
+# Example 1
+# Input: $source = "fuck"
+#        $target = "fcuk"
+# Output: true
+# The swapping of 'u' with 'c' makes it buddy strings.
+#
+# Example 2
+# Input: $source = "love"
+#        $target = "love"
+# Output: false
+#
+# Example 3
+# Input: $source = "fodo"
+#        $target = "food"
+# Output: true
+#
+# Example 4
+# Input: $source = "feed"
+#        $target = "feed"
+# Output: true
+
+
+# Function to check if two strings are buddy strings
+sub are_buddy_strings {
+    my ($source, $target) = @_;
+
+    # Must be same length
+    return 0 if length($source) != length($target);
+
+    # Find differences
+    my @diff_positions = ();
+    for my $i (0 .. length($source) - 1) {
+        if (substr($source, $i, 1) ne substr($target, $i, 1)) {
+            push @diff_positions, $i;
+        }
+    }
+
+    # Case 1: No differences - strings are identical
+    if (@diff_positions == 0) {
+        # Check if source has duplicate characters (can swap identical chars)
+        my %char_count = ();
+        for my $char (split //, $source) {
+            $char_count{$char}++;
+            return 1 if $char_count{$char} >= 2;  # Found duplicate
+        }
+        return 0;  # No duplicates, can't swap
+    }
+
+    # Case 2: Exactly 2 differences
+    elsif (@diff_positions == 2) {
+        my ($pos1, $pos2) = @diff_positions;
+        # Check if swapping these positions makes strings equal
+        return (substr($source, $pos1, 1) eq substr($target, $pos2, 1) &&
+                substr($source, $pos2, 1) eq substr($target, $pos1, 1));
+    }
+
+    # Case 3: More than 2 differences - impossible with single swap
+    else {
+        return 0;
+    }
+}
+
+# Test cases from the problem
+my @test_cases = (
+              ["fuck", "fcuk", 1, "Swapping 'u' with 'c'"]
+             ,["love", "love", 0, "Identical with no duplicates"]
+             ,["fodo", "food", 1, "Swapping 'd' with 'o'"]
+             ,["feed", "feed", 1, "Identical with duplicate 'e'"]
+             ,["abc" , "def" , 0, "Completely different"]
+             ,["abcd", "abc" , 0, "Different lengths"]
+             ,["ab"  , "ba"  , 1, "Simple swap"]
+             ,["aa"  , "aa"  , 1, "Identical with duplicates"]
+             ,["abc" , "acb" , 1, "Swap b and c"]
+             ,["abcd", "badc", 0, "Too many differences"]
+);
+
+say "Testing Buddy Strings:\n";
+
+foreach my $test (@test_cases) {
+    my ($source, $target, $expected, $description) = @$test;
+    my $result = are_buddy_strings($source, $target);
+    my $status = ($result == $expected) ? "OK" : "ERROR";
+
+    printf "%s Source: %-6s Target: %-6s => %s (Expected: %s)  %s\n"
+           , $status, "\"$source\"", "\"$target\""
+           , $result ? "true" : "false"
+           , $expected ? "true" : "false"
+           , $description
+           f;
+}
+
+# Command line testing
+if (@ARGV >= 2) {
+    say "\nCommand line test:";
+    my $result = are_buddy_strings($ARGV[0], $ARGV[1]);
+    say "Source: \"$ARGV[0]\", Target: \"$ARGV[1]\" => " . ($result ? "true" : "false");
+}
diff --git a/stats/pwc-current.json b/stats/pwc-current.json
index d4f61aac0d..001fe36430 100644
--- a/stats/pwc-current.json
+++ b/stats/pwc-current.json
@@ -119,6 +119,16 @@
          {
             "data" : [
                [
+                  "Perl",
+                  2
+               ]
+            ],
+            "id" : "Fabio Valeri",
+            "name" : "Fabio Valeri"
+         },
+         {
+            "data" : [
+               [
                   "Raku",
                   2
                ]
@@ -485,6 +495,11 @@
                "y" : 2
             },
             {
+               "drilldown" : "Fabio Valeri",
+               "name" : "Fabio Valeri",
+               "y" : 2
+            },
+            {
                "drilldown" : "Feng Chang",
                "name" : "Feng Chang",
                "y" : 2
@@ -609,7 +624,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 34] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 35] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge - 331"
diff --git a/stats/pwc-language-breakdown-2019.json b/stats/pwc-language-breakdown-2019.json
index f92d7f2b5e..5c868efb3b 100644
--- a/stats/pwc-language-breakdown-2019.json
+++ b/stats/pwc-language-breakdown-2019.json
@@ -970,7 +970,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge Language"
diff --git a/stats/pwc-language-breakdown-2020.json b/stats/pwc-language-breakdown-2020.json
index 7488e00a86..56c53696bf 100644
--- a/stats/pwc-language-breakdown-2020.json
+++ b/stats/pwc-language-breakdown-2020.json
@@ -1223,7 +1223,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge Language"
diff --git a/stats/pwc-language-breakdown-2021.json b/stats/pwc-language-breakdown-2021.json
index b16afe756b..540e3158c2 100644
--- a/stats/pwc-language-breakdown-2021.json
+++ b/stats/pwc-language-breakdown-2021.json
@@ -1223,7 +1223,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge Language"
diff --git a/stats/pwc-language-breakdown-2022.json b/stats/pwc-language-breakdown-2022.json
index 3643368d38..bd9b0e10bd 100644
--- a/stats/pwc-language-breakdown-2022.json
+++ b/stats/pwc-language-breakdown-2022.json
@@ -1223,7 +1223,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge Language"
diff --git a/stats/pwc-language-breakdown-2023.json b/stats/pwc-language-breakdown-2023.json
index fb36c98ed0..c7c4a7d704 100644
--- a/stats/pwc-language-breakdown-2023.json
+++ b/stats/pwc-language-breakdown-2023.json
@@ -1200,7 +1200,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge Language"
diff --git a/stats/pwc-language-breakdown-2024.json b/stats/pwc-language-breakdown-2024.json
index e1fbbc5124..7221e2c3e2 100644
--- a/stats/pwc-language-breakdown-2024.json
+++ b/stats/pwc-language-breakdown-2024.json
@@ -1246,7 +1246,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge Language"
diff --git a/stats/pwc-language-breakdown-2025.json b/stats/pwc-language-breakdown-2025.json
index 481bca6794..1df3292cf6 100644
--- a/stats/pwc-language-breakdown-2025.json
+++ b/stats/pwc-language-breakdown-2025.json
@@ -8,7 +8,7 @@
             "data" : [
                [
                   "Perl",
-                  50
+                  52
                ],
                [
                   "Raku",
@@ -547,7 +547,7 @@
             {
                "drilldown" : "331",
                "name" : "331",
-               "y" : 100
+               "y" : 102
             },
             {
                "drilldown" : "330",
@@ -694,7 +694,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge Language"
diff --git a/stats/pwc-language-breakdown-summary.json b/stats/pwc-language-breakdown-summary.json
index 7f784bde26..3d54487678 100644
--- a/stats/pwc-language-breakdown-summary.json
+++ b/stats/pwc-language-breakdown-summary.json
@@ -10,7 +10,7 @@
          "data" : [
             [
                "Perl",
-               17104
+               17106
             ],
             [
                "Raku",
@@ -37,7 +37,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge Contributions [2019 - 2025]"
diff --git a/stats/pwc-leaders.json b/stats/pwc-leaders.json
index 69cb4363a6..ee344908b3 100644
--- a/stats/pwc-leaders.json
+++ b/stats/pwc-leaders.json
@@ -1049,7 +1049,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Click the columns to drilldown the score breakdown. Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Click the columns to drilldown the score breakdown. Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "Team Leaders (TOP 50)"
diff --git a/stats/pwc-summary-1-30.json b/stats/pwc-summary-1-30.json
index dd3bf0295a..0c78f615f6 100644
--- a/stats/pwc-summary-1-30.json
+++ b/stats/pwc-summary-1-30.json
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-121-150.json b/stats/pwc-summary-121-150.json
index aea9a2bf7a..252e9da71c 100644
--- a/stats/pwc-summary-121-150.json
+++ b/stats/pwc-summary-121-150.json
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-151-180.json b/stats/pwc-summary-151-180.json
index f34f105539..a7ff809091 100644
--- a/stats/pwc-summary-151-180.json
+++ b/stats/pwc-summary-151-180.json
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-181-210.json b/stats/pwc-summary-181-210.json
index 753d68436b..fc174a7256 100644
--- a/stats/pwc-summary-181-210.json
+++ b/stats/pwc-summary-181-210.json
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-211-240.json b/stats/pwc-summary-211-240.json
index c8e3789687..9a16eb15dc 100644
--- a/stats/pwc-summary-211-240.json
+++ b/stats/pwc-summary-211-240.json
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-241-270.json b/stats/pwc-summary-241-270.json
index d6200e01ba..6c20e5f6ed 100644
--- a/stats/pwc-summary-241-270.json
+++ b/stats/pwc-summary-241-270.json
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-271-300.json b/stats/pwc-summary-271-300.json
index 9dab42172a..03103bba92 100644
--- a/stats/pwc-summary-271-300.json
+++ b/stats/pwc-summary-271-300.json
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-301-330.json b/stats/pwc-summary-301-330.json
index 88ac4d4e58..f147b6f40d 100644
--- a/stats/pwc-summary-301-330.json
+++ b/stats/pwc-summary-301-330.json
@@ -106,7 +106,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 27] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 27] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-31-60.json b/stats/pwc-summary-31-60.json
index bdcf22e8f3..3aec9d8078 100644
--- a/stats/pwc-summary-31-60.json
+++ b/stats/pwc-summary-31-60.json
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-61-90.json b/stats/pwc-summary-61-90.json
index 4bd124758b..d4699715aa 100644
--- a/stats/pwc-summary-61-90.json
+++ b/stats/pwc-summary-61-90.json
@@ -35,7 +35,7 @@
             396,
             651,
             2,
-            3,
+            5,
             8,
             22,
             0,
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary-91-120.json b/stats/pwc-summary-91-120.json
index a15ad71aa4..c62fe8c451 100644
--- a/stats/pwc-summary-91-120.json
+++ b/stats/pwc-summary-91-120.json
@@ -115,7 +115,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 30] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 30] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-summary.json b/stats/pwc-summary.json
index f31f5fac33..34376f1dc9 100644
--- a/stats/pwc-summary.json
+++ b/stats/pwc-summary.json
@@ -95,7 +95,7 @@
             202,
             326,
             1,
-            2,
+            3,
             4,
             12,
             0,
@@ -396,8 +396,8 @@
             6,
             0,
             0,
-            9,
             1,
+            9,
             0,
             104,
             0,
@@ -1006,7 +1006,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "[Champions: 327] Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "[Champions: 327] Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge [2019 - 2025]"
diff --git a/stats/pwc-yearly-language-summary.json b/stats/pwc-yearly-language-summary.json
index 58064d7d03..918cc0f29b 100644
--- a/stats/pwc-yearly-language-summary.json
+++ b/stats/pwc-yearly-language-summary.json
@@ -8,7 +8,7 @@
             "data" : [
                [
                   "Perl",
-                  1333
+                  1335
                ],
                [
                   "Raku",
@@ -151,7 +151,7 @@
             {
                "drilldown" : "2025",
                "name" : "2025",
-               "y" : 2537
+               "y" : 2539
             },
             {
                "drilldown" : "2024",
@@ -188,7 +188,7 @@
       }
    ],
    "subtitle" : {
-      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:37:05 GMT"
+      "text" : "Click the columns to drilldown the language breakdown. Last updated at 2025-07-31 09:53:03 GMT"
    },
    "title" : {
       "text" : "The Weekly Challenge Language"