use strict; use warnings; my @arrays = ( [ qw( A 1 2 3 4 5 ) ], [ qw( B 1 2 5 6 ) ], [ qw( C 2 3 ) ], ); my %actors; my %actors_by_role; foreach my $array (@arrays) { my @roles = @$array; my $actor = shift(@roles); $actors{$actor} = 1; foreach my $role (@roles) { $actors_by_role{$role}{$actor} = 1; } } my @roles = sort keys %actors_by_role; my @actors = sort keys %actors; { foreach my $actor (@actors) { print("\t", $actor); } print("\n"); } foreach my $role (@roles) { print($role); foreach my $actor (@actors) { print("\t", $actors_by_role{$role}{$actor} ? 'X' : ' '); } print("\n"); }