Challenge 289 Task 1 and 2 solutions in Perl by Matthias Muth - Update

1 files changed, 34 insertions, 4 deletions

diff --git a/challenge-289/matthias-muth/perl/ch-2.pl b/challenge-289/matthias-muth/perl/ch-2.pl
index f86c3e78ba..44cc388bc7 100755
--- a/challenge-289/matthias-muth/perl/ch-2.pl
+++ b/challenge-289/matthias-muth/perl/ch-2.pl
@@ -10,14 +10,42 @@
 
 use v5.36;
 
-use utf8;
-binmode(STDOUT, ":utf8");
-
+# Fisher-Yates shuffle (or Knuth shuffle).
 sub jumble_string( $str ) {
     my @chars = split "", $str;
     return join "", map { splice @chars, rand( @chars ), 1, () } 0..$#chars;
 }
 
+# Modern version (Durstenfeld shuffle).
+sub jumble_string( $str ) {
+    my @chars = split "", $str;
+    for my $i ( reverse 0..$#chars ) {
+        my $j = rand( $i + 1 );
+        ( $chars[$i], $chars[$j] ) = ( $chars[$j], $chars[$i] );
+    }
+    return join "", @chars;
+}
+
+# Modern version (Durstenfeld shuffle).
+sub jumble_string( $str ) {
+    my @chars = split "", $str;
+    for my $i ( reverse 0..$#chars ) {
+        my $j = rand( $i + 1 );
+        ( $chars[$i], $chars[$j] ) = ( $chars[$j], $chars[$i] );
+    }
+    return join "", @chars;
+}
+
+# Durstenfeld shuffle directly on characters.
+sub jumble_string( $str ) {
+    for my $i ( reverse 0 .. length( $str ) - 1 ) {
+        my $j = rand( $i + 1 );
+        ( substr( $str, $i, 1 ), substr( $str, $j, 1 ) ) =
+            ( substr( $str, $j, 1 ), substr( $str, $i, 1 ) );
+    }
+    return $str;
+}
+
 sub jumbled_letters( $str ) {
     return $str =~ s{
             (?<=[A-Za-z]) [a-z]+ (?=[a-z])
@@ -27,7 +55,9 @@ sub jumbled_letters( $str ) {
 }
 
 use Test2::V0 qw( -no_srand );
-use Data::Dump qw( pp );
+
+use utf8;
+binmode(STDOUT, ":utf8");
 
 my $input_text = <<EOF;
 According to a researchch at Cambridge University, it doesn’t matter in what