Fix yet another error

1 files changed, 13 insertions, 9 deletions

diff --git a/challenge-209/wlmb/perl/ch-2.pl b/challenge-209/wlmb/perl/ch-2.pl
index 46ad3198c8..ff3285d04a 100755
--- a/challenge-209/wlmb/perl/ch-2.pl
+++ b/challenge-209/wlmb/perl/ch-2.pl
@@ -5,20 +5,24 @@
 # See https://wlmb.github.io/2023/03/20/PWC209/#task-2-merge-account
 use v5.36;
 use English;
+use List::Util qw(uniq);
 my %line_of;
+my %addresses_of;
 my @names;
 while(<>){
     chomp;
-    my ($name, @addresses)=split / /;
+    # Assume input is of the form: name address1 address2...
+    my ($name, @addresses)=split ' ';
     next unless $name; # skip empty lines
     $names[$INPUT_LINE_NUMBER]=$name;
-    my ($merged)=grep {defined $_} map {$line_of{$_}} @addresses;
-    $merged//=$INPUT_LINE_NUMBER; # current line by default
-    @line_of{@addresses}=($merged) x @addresses;
+    my @merged=grep {defined $_} map {$line_of{$_}} @addresses; # lines to merge with current
+    push @addresses, map {@{$addresses_of{$_}}} @merged;        # add their addresses
+    @addresses=uniq @addresses;                                 # avoid repetitions
+    delete $addresses_of{$_} for @merged;                       # delete merged lines
+    @line_of{@addresses}=($INPUT_LINE_NUMBER) x @addresses;     # map addresses to line
+    $addresses_of{$INPUT_LINE_NUMBER}=[@addresses];             # map line to addresses
 }
-my %accounts;
-push @{$accounts{$line_of{$_}}}, $_ for(keys %line_of);
-# Sort output by account name and line number, and sort addresses
+# Output. Sort by account name and line number, and sort addresses
 say "$names[$_] ($_): ", join " ",
-    sort {$a cmp $b} @{$accounts{$_}}
-    for sort {$names[$a] cmp $names[$b] || $a <=>$b} keys %accounts;
+    sort {$a cmp $b} @{$addresses_of{$_}}
+    for sort {$names[$a] cmp $names[$b] || $a <=>$b} keys %addresses_of;