It's destructive => There was no requirement to not do that. I'll resort to my old saying "If it passes all the test cases, it's correct :)"

Repeated splits => Just concatenate as we go, and fix up right before the end. Is it really faster? I don't know and I don't care :)

Like so: 

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11106779
use warnings;
use List::Util qw( uniq );

my @AoH = (
  { count => 1, origin => "AMG", targetL => "foisonnement" },
  { count => 1, origin => "IDBR", targetL => "foisonnement" },
  { count => 1, origin => "IWWF", targetL => "gonfler" },
  { count => 1, origin => "IWWF", targetL => "due" },
  { count => 1, origin => "IWWF", targetL => "due" },
);

my %seen;
my @AoHfinal = grep { $_->{origin} = join ' ', uniq split ' ', $_->{or
+igin} }
  map
    {
    if( my $prev = $seen{$_->{targetL}} )
      {
      $prev->{count} += $_->{count};
      $prev->{origin} .= ' ' . $_->{origin};
      () # skip duplicate
      }
    else
      {
      $seen{$_->{targetL}} = { %$_ };
      }
    } @AoH;

use Data::Dump 'dd'; dd @AoHfinal;

[download]

In reply to Re^3: Counting elements in array of cases by tybalt89
in thread Counting elements in array of cases by Anonymous Monk

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