Solution to task 2

1 files changed, 89 insertions, 0 deletions

diff --git a/challenge-284/jo-37/perl/ch-2.pl b/challenge-284/jo-37/perl/ch-2.pl
new file mode 100755
index 0000000000..5536c97cbc
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+++ b/challenge-284/jo-37/perl/ch-2.pl
@@ -0,0 +1,89 @@
+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0;
+use experimental 'signatures';
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV == 2;
+usage: $0 [-examples] [-tests] [N1,N2,... M1,M2,...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+N1,N2,...
+    numbers in \@list1, comma and/or space separated
+
+M1,M2,...
+    numbers in \@list2, comma and/or space separated
+
+EOS
+
+
+### Input and Output
+
+say "(@{relative_sort(map [split /[, ] */, $_], @ARGV)})";
+
+
+### Implementation
+#
+# For details see:
+# https://github.sommrey.de/the-bears-den/2024/08/30/ch-284.html#task-2
+
+sub relative_sort ($list1, $list2) {
+    (\my %list2)->@{@$list2} = ();
+    my @part2;
+    for my $n (@$list1) {
+        if (exists $list2{$n}) {
+            $list2{$n}++;
+        } else {
+            push @part2, $n;
+        }
+    }
+
+    [
+        (map +($_) x $list2{$_}, @$list2),
+        (sort {$a <=> $b} @part2),
+    ];
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is relative_sort( [2, 3, 9, 3, 1, 4, 6, 7, 2, 8, 5],
+                [2, 1, 4, 3, 5, 6]),
+                [2, 2, 1, 4, 3, 3, 5, 6, 7, 8, 9],
+                'example 1';
+        is relative_sort( [3, 3, 4, 6, 2, 4, 2, 1, 3],
+                [1, 3, 2]),
+                [1, 3, 3, 3, 2, 2, 4, 4, 6],
+                'example 2';
+        is relative_sort( [3, 0, 5, 0, 2, 1, 4, 1, 1],
+                [1, 0, 3, 2]),
+                [1, 1, 1, 0, 0, 3, 2, 4, 5],
+                'example 3';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is relative_sort( [-20, 0, 1, 2],
+                [2, 1]),
+                [2, 1, -20, 0],
+                'negative';
+    }
+
+
+    done_testing;
+    exit;
+}